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Commit 2600a46e authored by Linus Torvalds's avatar Linus Torvalds
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Merge tag 'trace-v4.7' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace 

Pull tracing updates from Steven Rostedt:
 "This includes two new updates for the ftrace infrastructure.

   - With the changing of the code for filtering events by pid, from a
     list of pids to a bitmask, we can now easily implement following
     forks.  With a new tracing option "event-fork" which, when set,
     will have tasks with pids in set_event_pid, when they fork, to have
     their child pids added to set_event_pid and the child will be
     traced as well.

     Note, if "event-fork" is set and a task with its pid in
     set_event_pid exits, its pid will be removed from set_event_pid

   - The addition of Tom Zanussi's hist triggers.  This includes a very
     thorough documentatino on how to use the hist triggers with events.
     This introduces a quick and easy way to get histogram data from
     events and their fields.

  Some other cleanups and updates were added as well.  Like Masami
  Hiramatsu added test cases for the event trigger and hist triggers.
  Also I added a speed up of filtering by using a temp buffer when
  filters are set"

* tag 'trace-v4.7' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: (45 commits)
  tracing: Use temp buffer when filtering events
  tracing: Remove TRACE_EVENT_FL_USE_CALL_FILTER logic
  tracing: Remove unused function trace_current_buffer_lock_reserve()
  tracing: Remove one use of trace_current_buffer_lock_reserve()
  tracing: Have trace_buffer_unlock_commit() call the _regs version with NULL
  tracing: Remove unused function trace_current_buffer_discard_commit()
  tracing: Move trace_buffer_unlock_commit{_regs}() to local header
  tracing: Fold filter_check_discard() into its only user
  tracing: Make filter_check_discard() local
  tracing: Move event_trigger_unlock_commit{_regs}() to local header
  tracing: Don't use the address of the buffer array name in copy_from_user
  tracing: Handle tracing_map_alloc_elts() error path correctly
  tracing: Add check for NULL event field when creating hist field
  tracing: checking for NULL instead of IS_ERR()
  tracing: Do not inherit event-fork option for instances
  tracing: Fix unsigned comparison to zero in hist trigger code
  kselftests/ftrace: Add a test for log2 modifier of hist trigger
  tracing: Add hist trigger 'log2' modifier
  kselftests/ftrace: Add hist trigger testcases
  kselftests/ftrace : Add event trigger testcases
  ...
parents 03e1aa1c 0fc1b09f
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Documentation/trace/events.txt
View file @ 2600a46e
......@@ -512,3 +512,1558 @@ The following commands are supported:
Note that there can be only one traceon or traceoff trigger per
triggering event.
- hist
This command aggregates event hits into a hash table keyed on one or
more trace event format fields (or stacktrace) and a set of running
totals derived from one or more trace event format fields and/or
event counts (hitcount).
The format of a hist trigger is as follows:
hist:keys=<field1[,field2,...]>[:values=<field1[,field2,...]>]
[:sort=<field1[,field2,...]>][:size=#entries][:pause][:continue]
[:clear][:name=histname1] [if <filter>]
When a matching event is hit, an entry is added to a hash table
using the key(s) and value(s) named. Keys and values correspond to
fields in the event's format description. Values must correspond to
numeric fields - on an event hit, the value(s) will be added to a
sum kept for that field. The special string 'hitcount' can be used
in place of an explicit value field - this is simply a count of
event hits. If 'values' isn't specified, an implicit 'hitcount'
value will be automatically created and used as the only value.
Keys can be any field, or the special string 'stacktrace', which
will use the event's kernel stacktrace as the key. The keywords
'keys' or 'key' can be used to specify keys, and the keywords
'values', 'vals', or 'val' can be used to specify values. Compound
keys consisting of up to two fields can be specified by the 'keys'
keyword. Hashing a compound key produces a unique entry in the
table for each unique combination of component keys, and can be
useful for providing more fine-grained summaries of event data.
Additionally, sort keys consisting of up to two fields can be
specified by the 'sort' keyword. If more than one field is
specified, the result will be a 'sort within a sort': the first key
is taken to be the primary sort key and the second the secondary
key. If a hist trigger is given a name using the 'name' parameter,
its histogram data will be shared with other triggers of the same
name, and trigger hits will update this common data. Only triggers
with 'compatible' fields can be combined in this way; triggers are
'compatible' if the fields named in the trigger share the same
number and type of fields and those fields also have the same names.
Note that any two events always share the compatible 'hitcount' and
'stacktrace' fields and can therefore be combined using those
fields, however pointless that may be.
'hist' triggers add a 'hist' file to each event's subdirectory.
Reading the 'hist' file for the event will dump the hash table in
its entirety to stdout. If there are multiple hist triggers
attached to an event, there will be a table for each trigger in the
output. The table displayed for a named trigger will be the same as
any other instance having the same name. Each printed hash table
entry is a simple list of the keys and values comprising the entry;
keys are printed first and are delineated by curly braces, and are
followed by the set of value fields for the entry. By default,
numeric fields are displayed as base-10 integers. This can be
modified by appending any of the following modifiers to the field
name:
.hex display a number as a hex value
.sym display an address as a symbol
.sym-offset display an address as a symbol and offset
.syscall display a syscall id as a system call name
.execname display a common_pid as a program name
Note that in general the semantics of a given field aren't
interpreted when applying a modifier to it, but there are some
restrictions to be aware of in this regard:
- only the 'hex' modifier can be used for values (because values
are essentially sums, and the other modifiers don't make sense
in that context).
- the 'execname' modifier can only be used on a 'common_pid'. The
reason for this is that the execname is simply the 'comm' value
saved for the 'current' process when an event was triggered,
which is the same as the common_pid value saved by the event
tracing code. Trying to apply that comm value to other pid
values wouldn't be correct, and typically events that care save
pid-specific comm fields in the event itself.
A typical usage scenario would be the following to enable a hist
trigger, read its current contents, and then turn it off:
# echo 'hist:keys=skbaddr.hex:vals=len' > \
/sys/kernel/debug/tracing/events/net/netif_rx/trigger
# cat /sys/kernel/debug/tracing/events/net/netif_rx/hist
# echo '!hist:keys=skbaddr.hex:vals=len' > \
/sys/kernel/debug/tracing/events/net/netif_rx/trigger
The trigger file itself can be read to show the details of the
currently attached hist trigger. This information is also displayed
at the top of the 'hist' file when read.
By default, the size of the hash table is 2048 entries. The 'size'
parameter can be used to specify more or fewer than that. The units
are in terms of hashtable entries - if a run uses more entries than
specified, the results will show the number of 'drops', the number
of hits that were ignored. The size should be a power of 2 between
128 and 131072 (any non- power-of-2 number specified will be rounded
up).
The 'sort' parameter can be used to specify a value field to sort
on. The default if unspecified is 'hitcount' and the default sort
order is 'ascending'. To sort in the opposite direction, append
.descending' to the sort key.
The 'pause' parameter can be used to pause an existing hist trigger
or to start a hist trigger but not log any events until told to do
so. 'continue' or 'cont' can be used to start or restart a paused
hist trigger.
The 'clear' parameter will clear the contents of a running hist
trigger and leave its current paused/active state.
Note that the 'pause', 'cont', and 'clear' parameters should be
applied using 'append' shell operator ('>>') if applied to an
existing trigger, rather than via the '>' operator, which will cause
the trigger to be removed through truncation.
- enable_hist/disable_hist
The enable_hist and disable_hist triggers can be used to have one
event conditionally start and stop another event's already-attached
hist trigger. Any number of enable_hist and disable_hist triggers
can be attached to a given event, allowing that event to kick off
and stop aggregations on a host of other events.
The format is very similar to the enable/disable_event triggers:
enable_hist:<system>:<event>[:count]
disable_hist:<system>:<event>[:count]
Instead of enabling or disabling the tracing of the target event
into the trace buffer as the enable/disable_event triggers do, the
enable/disable_hist triggers enable or disable the aggregation of
the target event into a hash table.
A typical usage scenario for the enable_hist/disable_hist triggers
would be to first set up a paused hist trigger on some event,
followed by an enable_hist/disable_hist pair that turns the hist
aggregation on and off when conditions of interest are hit:
# echo 'hist:keys=skbaddr.hex:vals=len:pause' > \
/sys/kernel/debug/tracing/events/net/netif_receive_skb/trigger
# echo 'enable_hist:net:netif_receive_skb if filename==/usr/bin/wget' > \
/sys/kernel/debug/tracing/events/sched/sched_process_exec/trigger
# echo 'disable_hist:net:netif_receive_skb if comm==wget' > \
/sys/kernel/debug/tracing/events/sched/sched_process_exit/trigger
The above sets up an initially paused hist trigger which is unpaused
and starts aggregating events when a given program is executed, and
which stops aggregating when the process exits and the hist trigger
is paused again.
The examples below provide a more concrete illustration of the
concepts and typical usage patterns discussed above.
6.2 'hist' trigger examples
---------------------------
The first set of examples creates aggregations using the kmalloc
event. The fields that can be used for the hist trigger are listed
in the kmalloc event's format file:
# cat /sys/kernel/debug/tracing/events/kmem/kmalloc/format
name: kmalloc
ID: 374
format:
field:unsigned short common_type; offset:0; size:2; signed:0;
field:unsigned char common_flags; offset:2; size:1; signed:0;
field:unsigned char common_preempt_count; offset:3; size:1; signed:0;
field:int common_pid; offset:4; size:4; signed:1;
field:unsigned long call_site; offset:8; size:8; signed:0;
field:const void * ptr; offset:16; size:8; signed:0;
field:size_t bytes_req; offset:24; size:8; signed:0;
field:size_t bytes_alloc; offset:32; size:8; signed:0;
field:gfp_t gfp_flags; offset:40; size:4; signed:0;
We'll start by creating a hist trigger that generates a simple table
that lists the total number of bytes requested for each function in
the kernel that made one or more calls to kmalloc:
# echo 'hist:key=call_site:val=bytes_req' > \
/sys/kernel/debug/tracing/events/kmem/kmalloc/trigger
This tells the tracing system to create a 'hist' trigger using the
call_site field of the kmalloc event as the key for the table, which
just means that each unique call_site address will have an entry
created for it in the table. The 'val=bytes_req' parameter tells
the hist trigger that for each unique entry (call_site) in the
table, it should keep a running total of the number of bytes
requested by that call_site.
We'll let it run for awhile and then dump the contents of the 'hist'
file in the kmalloc event's subdirectory (for readability, a number
of entries have been omitted):
# cat /sys/kernel/debug/tracing/events/kmem/kmalloc/hist
# trigger info: hist:keys=call_site:vals=bytes_req:sort=hitcount:size=2048 [active]
{ call_site: 18446744072106379007 } hitcount: 1 bytes_req: 176
{ call_site: 18446744071579557049 } hitcount: 1 bytes_req: 1024
{ call_site: 18446744071580608289 } hitcount: 1 bytes_req: 16384
{ call_site: 18446744071581827654 } hitcount: 1 bytes_req: 24
{ call_site: 18446744071580700980 } hitcount: 1 bytes_req: 8
{ call_site: 18446744071579359876 } hitcount: 1 bytes_req: 152
{ call_site: 18446744071580795365 } hitcount: 3 bytes_req: 144
{ call_site: 18446744071581303129 } hitcount: 3 bytes_req: 144
{ call_site: 18446744071580713234 } hitcount: 4 bytes_req: 2560
{ call_site: 18446744071580933750 } hitcount: 4 bytes_req: 736
.
.
.
{ call_site: 18446744072106047046 } hitcount: 69 bytes_req: 5576
{ call_site: 18446744071582116407 } hitcount: 73 bytes_req: 2336
{ call_site: 18446744072106054684 } hitcount: 136 bytes_req: 140504
{ call_site: 18446744072106224230 } hitcount: 136 bytes_req: 19584
{ call_site: 18446744072106078074 } hitcount: 153 bytes_req: 2448
{ call_site: 18446744072106062406 } hitcount: 153 bytes_req: 36720
{ call_site: 18446744071582507929 } hitcount: 153 bytes_req: 37088
{ call_site: 18446744072102520590 } hitcount: 273 bytes_req: 10920
{ call_site: 18446744071582143559 } hitcount: 358 bytes_req: 716
{ call_site: 18446744072106465852 } hitcount: 417 bytes_req: 56712
{ call_site: 18446744072102523378 } hitcount: 485 bytes_req: 27160
{ call_site: 18446744072099568646 } hitcount: 1676 bytes_req: 33520
Totals:
Hits: 4610
Entries: 45
Dropped: 0
The output displays a line for each entry, beginning with the key
specified in the trigger, followed by the value(s) also specified in
the trigger. At the beginning of the output is a line that displays
the trigger info, which can also be displayed by reading the
'trigger' file:
# cat /sys/kernel/debug/tracing/events/kmem/kmalloc/trigger
hist:keys=call_site:vals=bytes_req:sort=hitcount:size=2048 [active]
At the end of the output are a few lines that display the overall
totals for the run. The 'Hits' field shows the total number of
times the event trigger was hit, the 'Entries' field shows the total
number of used entries in the hash table, and the 'Dropped' field
shows the number of hits that were dropped because the number of
used entries for the run exceeded the maximum number of entries
allowed for the table (normally 0, but if not a hint that you may
want to increase the size of the table using the 'size' parameter).
Notice in the above output that there's an extra field, 'hitcount',
which wasn't specified in the trigger. Also notice that in the
trigger info output, there's a parameter, 'sort=hitcount', which
wasn't specified in the trigger either. The reason for that is that
every trigger implicitly keeps a count of the total number of hits
attributed to a given entry, called the 'hitcount'. That hitcount
information is explicitly displayed in the output, and in the
absence of a user-specified sort parameter, is used as the default
sort field.
The value 'hitcount' can be used in place of an explicit value in
the 'values' parameter if you don't really need to have any
particular field summed and are mainly interested in hit
frequencies.
To turn the hist trigger off, simply call up the trigger in the
command history and re-execute it with a '!' prepended:
# echo '!hist:key=call_site:val=bytes_req' > \
/sys/kernel/debug/tracing/events/kmem/kmalloc/trigger
Finally, notice that the call_site as displayed in the output above
isn't really very useful. It's an address, but normally addresses
are displayed in hex. To have a numeric field displayed as a hex
value, simply append '.hex' to the field name in the trigger:
# echo 'hist:key=call_site.hex:val=bytes_req' > \
/sys/kernel/debug/tracing/events/kmem/kmalloc/trigger
# cat /sys/kernel/debug/tracing/events/kmem/kmalloc/hist
# trigger info: hist:keys=call_site.hex:vals=bytes_req:sort=hitcount:size=2048 [active]
{ call_site: ffffffffa026b291 } hitcount: 1 bytes_req: 433
{ call_site: ffffffffa07186ff } hitcount: 1 bytes_req: 176
{ call_site: ffffffff811ae721 } hitcount: 1 bytes_req: 16384
{ call_site: ffffffff811c5134 } hitcount: 1 bytes_req: 8
{ call_site: ffffffffa04a9ebb } hitcount: 1 bytes_req: 511
{ call_site: ffffffff8122e0a6 } hitcount: 1 bytes_req: 12
{ call_site: ffffffff8107da84 } hitcount: 1 bytes_req: 152
{ call_site: ffffffff812d8246 } hitcount: 1 bytes_req: 24
{ call_site: ffffffff811dc1e5 } hitcount: 3 bytes_req: 144
{ call_site: ffffffffa02515e8 } hitcount: 3 bytes_req: 648
{ call_site: ffffffff81258159 } hitcount: 3 bytes_req: 144
{ call_site: ffffffff811c80f4 } hitcount: 4 bytes_req: 544
.
.
.
{ call_site: ffffffffa06c7646 } hitcount: 106 bytes_req: 8024
{ call_site: ffffffffa06cb246 } hitcount: 132 bytes_req: 31680
{ call_site: ffffffffa06cef7a } hitcount: 132 bytes_req: 2112
{ call_site: ffffffff8137e399 } hitcount: 132 bytes_req: 23232
{ call_site: ffffffffa06c941c } hitcount: 185 bytes_req: 171360
{ call_site: ffffffffa06f2a66 } hitcount: 185 bytes_req: 26640
{ call_site: ffffffffa036a70e } hitcount: 265 bytes_req: 10600
{ call_site: ffffffff81325447 } hitcount: 292 bytes_req: 584
{ call_site: ffffffffa072da3c } hitcount: 446 bytes_req: 60656
{ call_site: ffffffffa036b1f2 } hitcount: 526 bytes_req: 29456
{ call_site: ffffffffa0099c06 } hitcount: 1780 bytes_req: 35600
Totals:
Hits: 4775
Entries: 46
Dropped: 0
Even that's only marginally more useful - while hex values do look
more like addresses, what users are typically more interested in
when looking at text addresses are the corresponding symbols
instead. To have an address displayed as symbolic value instead,
simply append '.sym' or '.sym-offset' to the field name in the
trigger:
# echo 'hist:key=call_site.sym:val=bytes_req' > \
/sys/kernel/debug/tracing/events/kmem/kmalloc/trigger
# cat /sys/kernel/debug/tracing/events/kmem/kmalloc/hist
# trigger info: hist:keys=call_site.sym:vals=bytes_req:sort=hitcount:size=2048 [active]
{ call_site: [ffffffff810adcb9] syslog_print_all } hitcount: 1 bytes_req: 1024
{ call_site: [ffffffff8154bc62] usb_control_msg } hitcount: 1 bytes_req: 8
{ call_site: [ffffffffa00bf6fe] hidraw_send_report [hid] } hitcount: 1 bytes_req: 7
{ call_site: [ffffffff8154acbe] usb_alloc_urb } hitcount: 1 bytes_req: 192
{ call_site: [ffffffffa00bf1ca] hidraw_report_event [hid] } hitcount: 1 bytes_req: 7
{ call_site: [ffffffff811e3a25] __seq_open_private } hitcount: 1 bytes_req: 40
{ call_site: [ffffffff8109524a] alloc_fair_sched_group } hitcount: 2 bytes_req: 128
{ call_site: [ffffffff811febd5] fsnotify_alloc_group } hitcount: 2 bytes_req: 528
{ call_site: [ffffffff81440f58] __tty_buffer_request_room } hitcount: 2 bytes_req: 2624
{ call_site: [ffffffff81200ba6] inotify_new_group } hitcount: 2 bytes_req: 96
{ call_site: [ffffffffa05e19af] ieee80211_start_tx_ba_session [mac80211] } hitcount: 2 bytes_req: 464
{ call_site: [ffffffff81672406] tcp_get_metrics } hitcount: 2 bytes_req: 304
{ call_site: [ffffffff81097ec2] alloc_rt_sched_group } hitcount: 2 bytes_req: 128
{ call_site: [ffffffff81089b05] sched_create_group } hitcount: 2 bytes_req: 1424
.
.
.
{ call_site: [ffffffffa04a580c] intel_crtc_page_flip [i915] } hitcount: 1185 bytes_req: 123240
{ call_site: [ffffffffa0287592] drm_mode_page_flip_ioctl [drm] } hitcount: 1185 bytes_req: 104280
{ call_site: [ffffffffa04c4a3c] intel_plane_duplicate_state [i915] } hitcount: 1402 bytes_req: 190672
{ call_site: [ffffffff812891ca] ext4_find_extent } hitcount: 1518 bytes_req: 146208
{ call_site: [ffffffffa029070e] drm_vma_node_allow [drm] } hitcount: 1746 bytes_req: 69840
{ call_site: [ffffffffa045e7c4] i915_gem_do_execbuffer.isra.23 [i915] } hitcount: 2021 bytes_req: 792312
{ call_site: [ffffffffa02911f2] drm_modeset_lock_crtc [drm] } hitcount: 2592 bytes_req: 145152
{ call_site: [ffffffffa0489a66] intel_ring_begin [i915] } hitcount: 2629 bytes_req: 378576
{ call_site: [ffffffffa046041c] i915_gem_execbuffer2 [i915] } hitcount: 2629 bytes_req: 3783248
{ call_site: [ffffffff81325607] apparmor_file_alloc_security } hitcount: 5192 bytes_req: 10384
{ call_site: [ffffffffa00b7c06] hid_report_raw_event [hid] } hitcount: 5529 bytes_req: 110584
{ call_site: [ffffffff8131ebf7] aa_alloc_task_context } hitcount: 21943 bytes_req: 702176
{ call_site: [ffffffff8125847d] ext4_htree_store_dirent } hitcount: 55759 bytes_req: 5074265
Totals:
Hits: 109928
Entries: 71
Dropped: 0
Because the default sort key above is 'hitcount', the above shows a
the list of call_sites by increasing hitcount, so that at the bottom
we see the functions that made the most kmalloc calls during the
run. If instead we we wanted to see the top kmalloc callers in
terms of the number of bytes requested rather than the number of
calls, and we wanted the top caller to appear at the top, we can use
the 'sort' parameter, along with the 'descending' modifier:
# echo 'hist:key=call_site.sym:val=bytes_req:sort=bytes_req.descending' > \
/sys/kernel/debug/tracing/events/kmem/kmalloc/trigger
# cat /sys/kernel/debug/tracing/events/kmem/kmalloc/hist
# trigger info: hist:keys=call_site.sym:vals=bytes_req:sort=bytes_req.descending:size=2048 [active]
{ call_site: [ffffffffa046041c] i915_gem_execbuffer2 [i915] } hitcount: 2186 bytes_req: 3397464
{ call_site: [ffffffffa045e7c4] i915_gem_do_execbuffer.isra.23 [i915] } hitcount: 1790 bytes_req: 712176
{ call_site: [ffffffff8125847d] ext4_htree_store_dirent } hitcount: 8132 bytes_req: 513135
{ call_site: [ffffffff811e2a1b] seq_buf_alloc } hitcount: 106 bytes_req: 440128
{ call_site: [ffffffffa0489a66] intel_ring_begin [i915] } hitcount: 2186 bytes_req: 314784
{ call_site: [ffffffff812891ca] ext4_find_extent } hitcount: 2174 bytes_req: 208992
{ call_site: [ffffffff811ae8e1] __kmalloc } hitcount: 8 bytes_req: 131072
{ call_site: [ffffffffa04c4a3c] intel_plane_duplicate_state [i915] } hitcount: 859 bytes_req: 116824
{ call_site: [ffffffffa02911f2] drm_modeset_lock_crtc [drm] } hitcount: 1834 bytes_req: 102704
{ call_site: [ffffffffa04a580c] intel_crtc_page_flip [i915] } hitcount: 972 bytes_req: 101088
{ call_site: [ffffffffa0287592] drm_mode_page_flip_ioctl [drm] } hitcount: 972 bytes_req: 85536
{ call_site: [ffffffffa00b7c06] hid_report_raw_event [hid] } hitcount: 3333 bytes_req: 66664
{ call_site: [ffffffff8137e559] sg_kmalloc } hitcount: 209 bytes_req: 61632
.
.
.
{ call_site: [ffffffff81095225] alloc_fair_sched_group } hitcount: 2 bytes_req: 128
{ call_site: [ffffffff81097ec2] alloc_rt_sched_group } hitcount: 2 bytes_req: 128
{ call_site: [ffffffff812d8406] copy_semundo } hitcount: 2 bytes_req: 48
{ call_site: [ffffffff81200ba6] inotify_new_group } hitcount: 1 bytes_req: 48
{ call_site: [ffffffffa027121a] drm_getmagic [drm] } hitcount: 1 bytes_req: 48
{ call_site: [ffffffff811e3a25] __seq_open_private } hitcount: 1 bytes_req: 40
{ call_site: [ffffffff811c52f4] bprm_change_interp } hitcount: 2 bytes_req: 16
{ call_site: [ffffffff8154bc62] usb_control_msg } hitcount: 1 bytes_req: 8
{ call_site: [ffffffffa00bf1ca] hidraw_report_event [hid] } hitcount: 1 bytes_req: 7
{ call_site: [ffffffffa00bf6fe] hidraw_send_report [hid] } hitcount: 1 bytes_req: 7
Totals:
Hits: 32133
Entries: 81
Dropped: 0
To display the offset and size information in addition to the symbol
name, just use 'sym-offset' instead:
# echo 'hist:key=call_site.sym-offset:val=bytes_req:sort=bytes_req.descending' > \
/sys/kernel/debug/tracing/events/kmem/kmalloc/trigger
# cat /sys/kernel/debug/tracing/events/kmem/kmalloc/hist
# trigger info: hist:keys=call_site.sym-offset:vals=bytes_req:sort=bytes_req.descending:size=2048 [active]
{ call_site: [ffffffffa046041c] i915_gem_execbuffer2+0x6c/0x2c0 [i915] } hitcount: 4569 bytes_req: 3163720
{ call_site: [ffffffffa0489a66] intel_ring_begin+0xc6/0x1f0 [i915] } hitcount: 4569 bytes_req: 657936
{ call_site: [ffffffffa045e7c4] i915_gem_do_execbuffer.isra.23+0x694/0x1020 [i915] } hitcount: 1519 bytes_req: 472936
{ call_site: [ffffffffa045e646] i915_gem_do_execbuffer.isra.23+0x516/0x1020 [i915] } hitcount: 3050 bytes_req: 211832
{ call_site: [ffffffff811e2a1b] seq_buf_alloc+0x1b/0x50 } hitcount: 34 bytes_req: 148384
{ call_site: [ffffffffa04a580c] intel_crtc_page_flip+0xbc/0x870 [i915] } hitcount: 1385 bytes_req: 144040
{ call_site: [ffffffff811ae8e1] __kmalloc+0x191/0x1b0 } hitcount: 8 bytes_req: 131072
{ call_site: [ffffffffa0287592] drm_mode_page_flip_ioctl+0x282/0x360 [drm] } hitcount: 1385 bytes_req: 121880
{ call_site: [ffffffffa02911f2] drm_modeset_lock_crtc+0x32/0x100 [drm] } hitcount: 1848 bytes_req: 103488
{ call_site: [ffffffffa04c4a3c] intel_plane_duplicate_state+0x2c/0xa0 [i915] } hitcount: 461 bytes_req: 62696
{ call_site: [ffffffffa029070e] drm_vma_node_allow+0x2e/0xd0 [drm] } hitcount: 1541 bytes_req: 61640
{ call_site: [ffffffff815f8d7b] sk_prot_alloc+0xcb/0x1b0 } hitcount: 57 bytes_req: 57456
.
.
.
{ call_site: [ffffffff8109524a] alloc_fair_sched_group+0x5a/0x1a0 } hitcount: 2 bytes_req: 128
{ call_site: [ffffffffa027b921] drm_vm_open_locked+0x31/0xa0 [drm] } hitcount: 3 bytes_req: 96
{ call_site: [ffffffff8122e266] proc_self_follow_link+0x76/0xb0 } hitcount: 8 bytes_req: 96
{ call_site: [ffffffff81213e80] load_elf_binary+0x240/0x1650 } hitcount: 3 bytes_req: 84
{ call_site: [ffffffff8154bc62] usb_control_msg+0x42/0x110 } hitcount: 1 bytes_req: 8
{ call_site: [ffffffffa00bf6fe] hidraw_send_report+0x7e/0x1a0 [hid] } hitcount: 1 bytes_req: 7
{ call_site: [ffffffffa00bf1ca] hidraw_report_event+0x8a/0x120 [hid] } hitcount: 1 bytes_req: 7
Totals:
Hits: 26098
Entries: 64
Dropped: 0
We can also add multiple fields to the 'values' parameter. For
example, we might want to see the total number of bytes allocated
alongside bytes requested, and display the result sorted by bytes
allocated in a descending order:
# echo 'hist:keys=call_site.sym:values=bytes_req,bytes_alloc:sort=bytes_alloc.descending' > \
/sys/kernel/debug/tracing/events/kmem/kmalloc/trigger
# cat /sys/kernel/debug/tracing/events/kmem/kmalloc/hist
# trigger info: hist:keys=call_site.sym:vals=bytes_req,bytes_alloc:sort=bytes_alloc.descending:size=2048 [active]
{ call_site: [ffffffffa046041c] i915_gem_execbuffer2 [i915] } hitcount: 7403 bytes_req: 4084360 bytes_alloc: 5958016
{ call_site: [ffffffff811e2a1b] seq_buf_alloc } hitcount: 541 bytes_req: 2213968 bytes_alloc: 2228224
{ call_site: [ffffffffa0489a66] intel_ring_begin [i915] } hitcount: 7404 bytes_req: 1066176 bytes_alloc: 1421568
{ call_site: [ffffffffa045e7c4] i915_gem_do_execbuffer.isra.23 [i915] } hitcount: 1565 bytes_req: 557368 bytes_alloc: 1037760
{ call_site: [ffffffff8125847d] ext4_htree_store_dirent } hitcount: 9557 bytes_req: 595778 bytes_alloc: 695744
{ call_site: [ffffffffa045e646] i915_gem_do_execbuffer.isra.23 [i915] } hitcount: 5839 bytes_req: 430680 bytes_alloc: 470400
{ call_site: [ffffffffa04c4a3c] intel_plane_duplicate_state [i915] } hitcount: 2388 bytes_req: 324768 bytes_alloc: 458496
{ call_site: [ffffffffa02911f2] drm_modeset_lock_crtc [drm] } hitcount: 3911 bytes_req: 219016 bytes_alloc: 250304
{ call_site: [ffffffff815f8d7b] sk_prot_alloc } hitcount: 235 bytes_req: 236880 bytes_alloc: 240640
{ call_site: [ffffffff8137e559] sg_kmalloc } hitcount: 557 bytes_req: 169024 bytes_alloc: 221760
{ call_site: [ffffffffa00b7c06] hid_report_raw_event [hid] } hitcount: 9378 bytes_req: 187548 bytes_alloc: 206312
{ call_site: [ffffffffa04a580c] intel_crtc_page_flip [i915] } hitcount: 1519 bytes_req: 157976 bytes_alloc: 194432
.
.
.
{ call_site: [ffffffff8109bd3b] sched_autogroup_create_attach } hitcount: 2 bytes_req: 144 bytes_alloc: 192
{ call_site: [ffffffff81097ee8] alloc_rt_sched_group } hitcount: 2 bytes_req: 128 bytes_alloc: 128
{ call_site: [ffffffff8109524a] alloc_fair_sched_group } hitcount: 2 bytes_req: 128 bytes_alloc: 128
{ call_site: [ffffffff81095225] alloc_fair_sched_group } hitcount: 2 bytes_req: 128 bytes_alloc: 128
{ call_site: [ffffffff81097ec2] alloc_rt_sched_group } hitcount: 2 bytes_req: 128 bytes_alloc: 128
{ call_site: [ffffffff81213e80] load_elf_binary } hitcount: 3 bytes_req: 84 bytes_alloc: 96
{ call_site: [ffffffff81079a2e] kthread_create_on_node } hitcount: 1 bytes_req: 56 bytes_alloc: 64
{ call_site: [ffffffffa00bf6fe] hidraw_send_report [hid] } hitcount: 1 bytes_req: 7 bytes_alloc: 8
{ call_site: [ffffffff8154bc62] usb_control_msg } hitcount: 1 bytes_req: 8 bytes_alloc: 8
{ call_site: [ffffffffa00bf1ca] hidraw_report_event [hid] } hitcount: 1 bytes_req: 7 bytes_alloc: 8
Totals:
Hits: 66598
Entries: 65
Dropped: 0
Finally, to finish off our kmalloc example, instead of simply having
the hist trigger display symbolic call_sites, we can have the hist
trigger additionally display the complete set of kernel stack traces
that led to each call_site. To do that, we simply use the special
value 'stacktrace' for the key parameter:
# echo 'hist:keys=stacktrace:values=bytes_req,bytes_alloc:sort=bytes_alloc' > \
/sys/kernel/debug/tracing/events/kmem/kmalloc/trigger
The above trigger will use the kernel stack trace in effect when an
event is triggered as the key for the hash table. This allows the
enumeration of every kernel callpath that led up to a particular
event, along with a running total of any of the event fields for
that event. Here we tally bytes requested and bytes allocated for
every callpath in the system that led up to a kmalloc (in this case
every callpath to a kmalloc for a kernel compile):
# cat /sys/kernel/debug/tracing/events/kmem/kmalloc/hist
# trigger info: hist:keys=stacktrace:vals=bytes_req,bytes_alloc:sort=bytes_alloc:size=2048 [active]
{ stacktrace:
__kmalloc_track_caller+0x10b/0x1a0
kmemdup+0x20/0x50
hidraw_report_event+0x8a/0x120 [hid]
hid_report_raw_event+0x3ea/0x440 [hid]
hid_input_report+0x112/0x190 [hid]
hid_irq_in+0xc2/0x260 [usbhid]
__usb_hcd_giveback_urb+0x72/0x120
usb_giveback_urb_bh+0x9e/0xe0
tasklet_hi_action+0xf8/0x100
__do_softirq+0x114/0x2c0
irq_exit+0xa5/0xb0
do_IRQ+0x5a/0xf0
ret_from_intr+0x0/0x30
cpuidle_enter+0x17/0x20
cpu_startup_entry+0x315/0x3e0
rest_init+0x7c/0x80
} hitcount: 3 bytes_req: 21 bytes_alloc: 24
{ stacktrace:
__kmalloc_track_caller+0x10b/0x1a0
kmemdup+0x20/0x50
hidraw_report_event+0x8a/0x120 [hid]
hid_report_raw_event+0x3ea/0x440 [hid]
hid_input_report+0x112/0x190 [hid]
hid_irq_in+0xc2/0x260 [usbhid]
__usb_hcd_giveback_urb+0x72/0x120
usb_giveback_urb_bh+0x9e/0xe0
tasklet_hi_action+0xf8/0x100
__do_softirq+0x114/0x2c0
irq_exit+0xa5/0xb0
do_IRQ+0x5a/0xf0
ret_from_intr+0x0/0x30
} hitcount: 3 bytes_req: 21 bytes_alloc: 24
{ stacktrace:
kmem_cache_alloc_trace+0xeb/0x150
aa_alloc_task_context+0x27/0x40
apparmor_cred_prepare+0x1f/0x50
security_prepare_creds+0x16/0x20
prepare_creds+0xdf/0x1a0
SyS_capset+0xb5/0x200
system_call_fastpath+0x12/0x6a
} hitcount: 1 bytes_req: 32 bytes_alloc: 32
.
.
.
{ stacktrace:
__kmalloc+0x11b/0x1b0
i915_gem_execbuffer2+0x6c/0x2c0 [i915]
drm_ioctl+0x349/0x670 [drm]
do_vfs_ioctl+0x2f0/0x4f0
SyS_ioctl+0x81/0xa0
system_call_fastpath+0x12/0x6a
} hitcount: 17726 bytes_req: 13944120 bytes_alloc: 19593808
{ stacktrace:
__kmalloc+0x11b/0x1b0
load_elf_phdrs+0x76/0xa0
load_elf_binary+0x102/0x1650
search_binary_handler+0x97/0x1d0
do_execveat_common.isra.34+0x551/0x6e0
SyS_execve+0x3a/0x50
return_from_execve+0x0/0x23
} hitcount: 33348 bytes_req: 17152128 bytes_alloc: 20226048
{ stacktrace:
kmem_cache_alloc_trace+0xeb/0x150
apparmor_file_alloc_security+0x27/0x40
security_file_alloc+0x16/0x20
get_empty_filp+0x93/0x1c0
path_openat+0x31/0x5f0
do_filp_open+0x3a/0x90
do_sys_open+0x128/0x220
SyS_open+0x1e/0x20
system_call_fastpath+0x12/0x6a
} hitcount: 4766422 bytes_req: 9532844 bytes_alloc: 38131376
{ stacktrace:
__kmalloc+0x11b/0x1b0
seq_buf_alloc+0x1b/0x50
seq_read+0x2cc/0x370
proc_reg_read+0x3d/0x80
__vfs_read+0x28/0xe0
vfs_read+0x86/0x140
SyS_read+0x46/0xb0
system_call_fastpath+0x12/0x6a
} hitcount: 19133 bytes_req: 78368768 bytes_alloc: 78368768
Totals:
Hits: 6085872
Entries: 253
Dropped: 0
If you key a hist trigger on common_pid, in order for example to
gather and display sorted totals for each process, you can use the
special .execname modifier to display the executable names for the
processes in the table rather than raw pids. The example below
keeps a per-process sum of total bytes read:
# echo 'hist:key=common_pid.execname:val=count:sort=count.descending' > \
/sys/kernel/debug/tracing/events/syscalls/sys_enter_read/trigger
# cat /sys/kernel/debug/tracing/events/syscalls/sys_enter_read/hist
# trigger info: hist:keys=common_pid.execname:vals=count:sort=count.descending:size=2048 [active]
{ common_pid: gnome-terminal [ 3196] } hitcount: 280 count: 1093512
{ common_pid: Xorg [ 1309] } hitcount: 525 count: 256640
{ common_pid: compiz [ 2889] } hitcount: 59 count: 254400
{ common_pid: bash [ 8710] } hitcount: 3 count: 66369
{ common_pid: dbus-daemon-lau [ 8703] } hitcount: 49 count: 47739
{ common_pid: irqbalance [ 1252] } hitcount: 27 count: 27648
{ common_pid: 01ifupdown [ 8705] } hitcount: 3 count: 17216
{ common_pid: dbus-daemon [ 772] } hitcount: 10 count: 12396
{ common_pid: Socket Thread [ 8342] } hitcount: 11 count: 11264
{ common_pid: nm-dhcp-client. [ 8701] } hitcount: 6 count: 7424
{ common_pid: gmain [ 1315] } hitcount: 18 count: 6336
.
.
.
{ common_pid: postgres [ 1892] } hitcount: 2 count: 32
{ common_pid: postgres [ 1891] } hitcount: 2 count: 32
{ common_pid: gmain [ 8704] } hitcount: 2 count: 32
{ common_pid: upstart-dbus-br [ 2740] } hitcount: 21 count: 21
{ common_pid: nm-dispatcher.a [ 8696] } hitcount: 1 count: 16
{ common_pid: indicator-datet [ 2904] } hitcount: 1 count: 16
{ common_pid: gdbus [ 2998] } hitcount: 1 count: 16
{ common_pid: rtkit-daemon [ 2052] } hitcount: 1 count: 8
{ common_pid: init [ 1] } hitcount: 2 count: 2
Totals:
Hits: 2116
Entries: 51
Dropped: 0
Similarly, if you key a hist trigger on syscall id, for example to
gather and display a list of systemwide syscall hits, you can use
the special .syscall modifier to display the syscall names rather
than raw ids. The example below keeps a running total of syscall
counts for the system during the run:
# echo 'hist:key=id.syscall:val=hitcount' > \
/sys/kernel/debug/tracing/events/raw_syscalls/sys_enter/trigger
# cat /sys/kernel/debug/tracing/events/raw_syscalls/sys_enter/hist
# trigger info: hist:keys=id.syscall:vals=hitcount:sort=hitcount:size=2048 [active]
{ id: sys_fsync [ 74] } hitcount: 1
{ id: sys_newuname [ 63] } hitcount: 1
{ id: sys_prctl [157] } hitcount: 1
{ id: sys_statfs [137] } hitcount: 1
{ id: sys_symlink [ 88] } hitcount: 1
{ id: sys_sendmmsg [307] } hitcount: 1
{ id: sys_semctl [ 66] } hitcount: 1
{ id: sys_readlink [ 89] } hitcount: 3
{ id: sys_bind [ 49] } hitcount: 3
{ id: sys_getsockname [ 51] } hitcount: 3
{ id: sys_unlink [ 87] } hitcount: 3
{ id: sys_rename [ 82] } hitcount: 4
{ id: unknown_syscall [ 58] } hitcount: 4
{ id: sys_connect [ 42] } hitcount: 4
{ id: sys_getpid [ 39] } hitcount: 4
.
.
.
{ id: sys_rt_sigprocmask [ 14] } hitcount: 952
{ id: sys_futex [202] } hitcount: 1534
{ id: sys_write [ 1] } hitcount: 2689
{ id: sys_setitimer [ 38] } hitcount: 2797
{ id: sys_read [ 0] } hitcount: 3202
{ id: sys_select [ 23] } hitcount: 3773
{ id: sys_writev [ 20] } hitcount: 4531
{ id: sys_poll [ 7] } hitcount: 8314
{ id: sys_recvmsg [ 47] } hitcount: 13738
{ id: sys_ioctl [ 16] } hitcount: 21843
Totals:
Hits: 67612
Entries: 72
Dropped: 0
The syscall counts above provide a rough overall picture of system
call activity on the system; we can see for example that the most
popular system call on this system was the 'sys_ioctl' system call.
We can use 'compound' keys to refine that number and provide some
further insight as to which processes exactly contribute to the
overall ioctl count.
The command below keeps a hitcount for every unique combination of
system call id and pid - the end result is essentially a table
that keeps a per-pid sum of system call hits. The results are
sorted using the system call id as the primary key, and the
hitcount sum as the secondary key:
# echo 'hist:key=id.syscall,common_pid.execname:val=hitcount:sort=id,hitcount' > \
/sys/kernel/debug/tracing/events/raw_syscalls/sys_enter/trigger
# cat /sys/kernel/debug/tracing/events/raw_syscalls/sys_enter/hist
# trigger info: hist:keys=id.syscall,common_pid.execname:vals=hitcount:sort=id.syscall,hitcount:size=2048 [active]
{ id: sys_read [ 0], common_pid: rtkit-daemon [ 1877] } hitcount: 1
{ id: sys_read [ 0], common_pid: gdbus [ 2976] } hitcount: 1
{ id: sys_read [ 0], common_pid: console-kit-dae [ 3400] } hitcount: 1
{ id: sys_read [ 0], common_pid: postgres [ 1865] } hitcount: 1
{ id: sys_read [ 0], common_pid: deja-dup-monito [ 3543] } hitcount: 2
{ id: sys_read [ 0], common_pid: NetworkManager [ 890] } hitcount: 2
{ id: sys_read [ 0], common_pid: evolution-calen [ 3048] } hitcount: 2
{ id: sys_read [ 0], common_pid: postgres [ 1864] } hitcount: 2
{ id: sys_read [ 0], common_pid: nm-applet [ 3022] } hitcount: 2
{ id: sys_read [ 0], common_pid: whoopsie [ 1212] } hitcount: 2
.
.
.
{ id: sys_ioctl [ 16], common_pid: bash [ 8479] } hitcount: 1
{ id: sys_ioctl [ 16], common_pid: bash [ 3472] } hitcount: 12
{ id: sys_ioctl [ 16], common_pid: gnome-terminal [ 3199] } hitcount: 16
{ id: sys_ioctl [ 16], common_pid: Xorg [ 1267] } hitcount: 1808
{ id: sys_ioctl [ 16], common_pid: compiz [ 2994] } hitcount: 5580
.
.
.
{ id: sys_waitid [247], common_pid: upstart-dbus-br [ 2690] } hitcount: 3
{ id: sys_waitid [247], common_pid: upstart-dbus-br [ 2688] } hitcount: 16
{ id: sys_inotify_add_watch [254], common_pid: gmain [ 975] } hitcount: 2
{ id: sys_inotify_add_watch [254], common_pid: gmain [ 3204] } hitcount: 4
{ id: sys_inotify_add_watch [254], common_pid: gmain [ 2888] } hitcount: 4
{ id: sys_inotify_add_watch [254], common_pid: gmain [ 3003] } hitcount: 4
{ id: sys_inotify_add_watch [254], common_pid: gmain [ 2873] } hitcount: 4
{ id: sys_inotify_add_watch [254], common_pid: gmain [ 3196] } hitcount: 6
{ id: sys_openat [257], common_pid: java [ 2623] } hitcount: 2
{ id: sys_eventfd2 [290], common_pid: ibus-ui-gtk3 [ 2760] } hitcount: 4
{ id: sys_eventfd2 [290], common_pid: compiz [ 2994] } hitcount: 6
Totals:
Hits: 31536
Entries: 323
Dropped: 0
The above list does give us a breakdown of the ioctl syscall by
pid, but it also gives us quite a bit more than that, which we
don't really care about at the moment. Since we know the syscall
id for sys_ioctl (16, displayed next to the sys_ioctl name), we
can use that to filter out all the other syscalls:
# echo 'hist:key=id.syscall,common_pid.execname:val=hitcount:sort=id,hitcount if id == 16' > \
/sys/kernel/debug/tracing/events/raw_syscalls/sys_enter/trigger
# cat /sys/kernel/debug/tracing/events/raw_syscalls/sys_enter/hist
# trigger info: hist:keys=id.syscall,common_pid.execname:vals=hitcount:sort=id.syscall,hitcount:size=2048 if id == 16 [active]
{ id: sys_ioctl [ 16], common_pid: gmain [ 2769] } hitcount: 1
{ id: sys_ioctl [ 16], common_pid: evolution-addre [ 8571] } hitcount: 1
{ id: sys_ioctl [ 16], common_pid: gmain [ 3003] } hitcount: 1
{ id: sys_ioctl [ 16], common_pid: gmain [ 2781] } hitcount: 1
{ id: sys_ioctl [ 16], common_pid: gmain [ 2829] } hitcount: 1
{ id: sys_ioctl [ 16], common_pid: bash [ 8726] } hitcount: 1
{ id: sys_ioctl [ 16], common_pid: bash [ 8508] } hitcount: 1
{ id: sys_ioctl [ 16], common_pid: gmain [ 2970] } hitcount: 1
{ id: sys_ioctl [ 16], common_pid: gmain [ 2768] } hitcount: 1
.
.
.
{ id: sys_ioctl [ 16], common_pid: pool [ 8559] } hitcount: 45
{ id: sys_ioctl [ 16], common_pid: pool [ 8555] } hitcount: 48
{ id: sys_ioctl [ 16], common_pid: pool [ 8551] } hitcount: 48
{ id: sys_ioctl [ 16], common_pid: avahi-daemon [ 896] } hitcount: 66
{ id: sys_ioctl [ 16], common_pid: Xorg [ 1267] } hitcount: 26674
{ id: sys_ioctl [ 16], common_pid: compiz [ 2994] } hitcount: 73443
Totals:
Hits: 101162
Entries: 103
Dropped: 0
The above output shows that 'compiz' and 'Xorg' are far and away
the heaviest ioctl callers (which might lead to questions about
whether they really need to be making all those calls and to
possible avenues for further investigation.)
The compound key examples used a key and a sum value (hitcount) to
sort the output, but we can just as easily use two keys instead.
Here's an example where we use a compound key composed of the the
common_pid and size event fields. Sorting with pid as the primary
key and 'size' as the secondary key allows us to display an
ordered summary of the recvfrom sizes, with counts, received by
each process:
# echo 'hist:key=common_pid.execname,size:val=hitcount:sort=common_pid,size' > \
/sys/kernel/debug/tracing/events/syscalls/sys_enter_recvfrom/trigger
# cat /sys/kernel/debug/tracing/events/syscalls/sys_enter_recvfrom/hist
# trigger info: hist:keys=common_pid.execname,size:vals=hitcount:sort=common_pid.execname,size:size=2048 [active]
{ common_pid: smbd [ 784], size: 4 } hitcount: 1
{ common_pid: dnsmasq [ 1412], size: 4096 } hitcount: 672
{ common_pid: postgres [ 1796], size: 1000 } hitcount: 6
{ common_pid: postgres [ 1867], size: 1000 } hitcount: 10
{ common_pid: bamfdaemon [ 2787], size: 28 } hitcount: 2
{ common_pid: bamfdaemon [ 2787], size: 14360 } hitcount: 1
{ common_pid: compiz [ 2994], size: 8 } hitcount: 1
{ common_pid: compiz [ 2994], size: 20 } hitcount: 11
{ common_pid: gnome-terminal [ 3199], size: 4 } hitcount: 2
{ common_pid: firefox [ 8817], size: 4 } hitcount: 1
{ common_pid: firefox [ 8817], size: 8 } hitcount: 5
{ common_pid: firefox [ 8817], size: 588 } hitcount: 2
{ common_pid: firefox [ 8817], size: 628 } hitcount: 1
{ common_pid: firefox [ 8817], size: 6944 } hitcount: 1
{ common_pid: firefox [ 8817], size: 408880 } hitcount: 2
{ common_pid: firefox [ 8822], size: 8 } hitcount: 2
{ common_pid: firefox [ 8822], size: 160 } hitcount: 2
{ common_pid: firefox [ 8822], size: 320 } hitcount: 2
{ common_pid: firefox [ 8822], size: 352 } hitcount: 1
.
.
.
{ common_pid: pool [ 8923], size: 1960 } hitcount: 10
{ common_pid: pool [ 8923], size: 2048 } hitcount: 10
{ common_pid: pool [ 8924], size: 1960 } hitcount: 10
{ common_pid: pool [ 8924], size: 2048 } hitcount: 10
{ common_pid: pool [ 8928], size: 1964 } hitcount: 4
{ common_pid: pool [ 8928], size: 1965 } hitcount: 2
{ common_pid: pool [ 8928], size: 2048 } hitcount: 6
{ common_pid: pool [ 8929], size: 1982 } hitcount: 1
{ common_pid: pool [ 8929], size: 2048 } hitcount: 1
Totals:
Hits: 2016
Entries: 224
Dropped: 0
The above example also illustrates the fact that although a compound
key is treated as a single entity for hashing purposes, the sub-keys
it's composed of can be accessed independently.
The next example uses a string field as the hash key and
demonstrates how you can manually pause and continue a hist trigger.
In this example, we'll aggregate fork counts and don't expect a
large number of entries in the hash table, so we'll drop it to a
much smaller number, say 256:
# echo 'hist:key=child_comm:val=hitcount:size=256' > \
/sys/kernel/debug/tracing/events/sched/sched_process_fork/trigger
# cat /sys/kernel/debug/tracing/events/sched/sched_process_fork/hist
# trigger info: hist:keys=child_comm:vals=hitcount:sort=hitcount:size=256 [active]
{ child_comm: dconf worker } hitcount: 1
{ child_comm: ibus-daemon } hitcount: 1
{ child_comm: whoopsie } hitcount: 1
{ child_comm: smbd } hitcount: 1
{ child_comm: gdbus } hitcount: 1
{ child_comm: kthreadd } hitcount: 1
{ child_comm: dconf worker } hitcount: 1
{ child_comm: evolution-alarm } hitcount: 2
{ child_comm: Socket Thread } hitcount: 2
{ child_comm: postgres } hitcount: 2
{ child_comm: bash } hitcount: 3
{ child_comm: compiz } hitcount: 3
{ child_comm: evolution-sourc } hitcount: 4
{ child_comm: dhclient } hitcount: 4
{ child_comm: pool } hitcount: 5
{ child_comm: nm-dispatcher.a } hitcount: 8
{ child_comm: firefox } hitcount: 8
{ child_comm: dbus-daemon } hitcount: 8
{ child_comm: glib-pacrunner } hitcount: 10
{ child_comm: evolution } hitcount: 23
Totals:
Hits: 89
Entries: 20
Dropped: 0
If we want to pause the hist trigger, we can simply append :pause to
the command that started the trigger. Notice that the trigger info
displays as [paused]:
# echo 'hist:key=child_comm:val=hitcount:size=256:pause' >> \
/sys/kernel/debug/tracing/events/sched/sched_process_fork/trigger
# cat /sys/kernel/debug/tracing/events/sched/sched_process_fork/hist
# trigger info: hist:keys=child_comm:vals=hitcount:sort=hitcount:size=256 [paused]
{ child_comm: dconf worker } hitcount: 1
{ child_comm: kthreadd } hitcount: 1
{ child_comm: dconf worker } hitcount: 1
{ child_comm: gdbus } hitcount: 1
{ child_comm: ibus-daemon } hitcount: 1
{ child_comm: Socket Thread } hitcount: 2
{ child_comm: evolution-alarm } hitcount: 2
{ child_comm: smbd } hitcount: 2
{ child_comm: bash } hitcount: 3
{ child_comm: whoopsie } hitcount: 3
{ child_comm: compiz } hitcount: 3
{ child_comm: evolution-sourc } hitcount: 4
{ child_comm: pool } hitcount: 5
{ child_comm: postgres } hitcount: 6
{ child_comm: firefox } hitcount: 8
{ child_comm: dhclient } hitcount: 10
{ child_comm: emacs } hitcount: 12
{ child_comm: dbus-daemon } hitcount: 20
{ child_comm: nm-dispatcher.a } hitcount: 20
{ child_comm: evolution } hitcount: 35
{ child_comm: glib-pacrunner } hitcount: 59
Totals:
Hits: 199
Entries: 21
Dropped: 0
To manually continue having the trigger aggregate events, append
:cont instead. Notice that the trigger info displays as [active]
again, and the data has changed:
# echo 'hist:key=child_comm:val=hitcount:size=256:cont' >> \
/sys/kernel/debug/tracing/events/sched/sched_process_fork/trigger
# cat /sys/kernel/debug/tracing/events/sched/sched_process_fork/hist
# trigger info: hist:keys=child_comm:vals=hitcount:sort=hitcount:size=256 [active]
{ child_comm: dconf worker } hitcount: 1
{ child_comm: dconf worker } hitcount: 1
{ child_comm: kthreadd } hitcount: 1
{ child_comm: gdbus } hitcount: 1
{ child_comm: ibus-daemon } hitcount: 1
{ child_comm: Socket Thread } hitcount: 2
{ child_comm: evolution-alarm } hitcount: 2
{ child_comm: smbd } hitcount: 2
{ child_comm: whoopsie } hitcount: 3
{ child_comm: compiz } hitcount: 3
{ child_comm: evolution-sourc } hitcount: 4
{ child_comm: bash } hitcount: 5
{ child_comm: pool } hitcount: 5
{ child_comm: postgres } hitcount: 6
{ child_comm: firefox } hitcount: 8
{ child_comm: dhclient } hitcount: 11
{ child_comm: emacs } hitcount: 12
{ child_comm: dbus-daemon } hitcount: 22
{ child_comm: nm-dispatcher.a } hitcount: 22
{ child_comm: evolution } hitcount: 35
{ child_comm: glib-pacrunner } hitcount: 59
Totals:
Hits: 206
Entries: 21
Dropped: 0
The previous example showed how to start and stop a hist trigger by
appending 'pause' and 'continue' to the hist trigger command. A
hist trigger can also be started in a paused state by initially
starting the trigger with ':pause' appended. This allows you to
start the trigger only when you're ready to start collecting data
and not before. For example, you could start the trigger in a
paused state, then unpause it and do something you want to measure,
then pause the trigger again when done.
Of course, doing this manually can be difficult and error-prone, but
it is possible to automatically start and stop a hist trigger based
on some condition, via the enable_hist and disable_hist triggers.
For example, suppose we wanted to take a look at the relative
weights in terms of skb length for each callpath that leads to a
netif_receieve_skb event when downloading a decent-sized file using
wget.
First we set up an initially paused stacktrace trigger on the
netif_receive_skb event:
# echo 'hist:key=stacktrace:vals=len:pause' > \
/sys/kernel/debug/tracing/events/net/netif_receive_skb/trigger
Next, we set up an 'enable_hist' trigger on the sched_process_exec
event, with an 'if filename==/usr/bin/wget' filter. The effect of
this new trigger is that it will 'unpause' the hist trigger we just
set up on netif_receive_skb if and only if it sees a
sched_process_exec event with a filename of '/usr/bin/wget'. When
that happens, all netif_receive_skb events are aggregated into a
hash table keyed on stacktrace:
# echo 'enable_hist:net:netif_receive_skb if filename==/usr/bin/wget' > \
/sys/kernel/debug/tracing/events/sched/sched_process_exec/trigger
The aggregation continues until the netif_receive_skb is paused
again, which is what the following disable_hist event does by
creating a similar setup on the sched_process_exit event, using the
filter 'comm==wget':
# echo 'disable_hist:net:netif_receive_skb if comm==wget' > \
/sys/kernel/debug/tracing/events/sched/sched_process_exit/trigger
Whenever a process exits and the comm field of the disable_hist
trigger filter matches 'comm==wget', the netif_receive_skb hist
trigger is disabled.
The overall effect is that netif_receive_skb events are aggregated
into the hash table for only the duration of the wget. Executing a
wget command and then listing the 'hist' file will display the
output generated by the wget command:
$ wget https://www.kernel.org/pub/linux/kernel/v3.x/patch-3.19.xz
# cat /sys/kernel/debug/tracing/events/net/netif_receive_skb/hist
# trigger info: hist:keys=stacktrace:vals=len:sort=hitcount:size=2048 [paused]
{ stacktrace:
__netif_receive_skb_core+0x46d/0x990
__netif_receive_skb+0x18/0x60
netif_receive_skb_internal+0x23/0x90
napi_gro_receive+0xc8/0x100
ieee80211_deliver_skb+0xd6/0x270 [mac80211]
ieee80211_rx_handlers+0xccf/0x22f0 [mac80211]
ieee80211_prepare_and_rx_handle+0x4e7/0xc40 [mac80211]
ieee80211_rx+0x31d/0x900 [mac80211]
iwlagn_rx_reply_rx+0x3db/0x6f0 [iwldvm]
iwl_rx_dispatch+0x8e/0xf0 [iwldvm]
iwl_pcie_irq_handler+0xe3c/0x12f0 [iwlwifi]
irq_thread_fn+0x20/0x50
irq_thread+0x11f/0x150
kthread+0xd2/0xf0
ret_from_fork+0x42/0x70
} hitcount: 85 len: 28884
{ stacktrace:
__netif_receive_skb_core+0x46d/0x990
__netif_receive_skb+0x18/0x60
netif_receive_skb_internal+0x23/0x90
napi_gro_complete+0xa4/0xe0
dev_gro_receive+0x23a/0x360
napi_gro_receive+0x30/0x100
ieee80211_deliver_skb+0xd6/0x270 [mac80211]
ieee80211_rx_handlers+0xccf/0x22f0 [mac80211]
ieee80211_prepare_and_rx_handle+0x4e7/0xc40 [mac80211]
ieee80211_rx+0x31d/0x900 [mac80211]
iwlagn_rx_reply_rx+0x3db/0x6f0 [iwldvm]
iwl_rx_dispatch+0x8e/0xf0 [iwldvm]
iwl_pcie_irq_handler+0xe3c/0x12f0 [iwlwifi]
irq_thread_fn+0x20/0x50
irq_thread+0x11f/0x150
kthread+0xd2/0xf0
} hitcount: 98 len: 664329
{ stacktrace:
__netif_receive_skb_core+0x46d/0x990
__netif_receive_skb+0x18/0x60
process_backlog+0xa8/0x150
net_rx_action+0x15d/0x340
__do_softirq+0x114/0x2c0
do_softirq_own_stack+0x1c/0x30
do_softirq+0x65/0x70
__local_bh_enable_ip+0xb5/0xc0
ip_finish_output+0x1f4/0x840
ip_output+0x6b/0xc0
ip_local_out_sk+0x31/0x40
ip_send_skb+0x1a/0x50
udp_send_skb+0x173/0x2a0
udp_sendmsg+0x2bf/0x9f0
inet_sendmsg+0x64/0xa0
sock_sendmsg+0x3d/0x50
} hitcount: 115 len: 13030
{ stacktrace:
__netif_receive_skb_core+0x46d/0x990
__netif_receive_skb+0x18/0x60
netif_receive_skb_internal+0x23/0x90
napi_gro_complete+0xa4/0xe0
napi_gro_flush+0x6d/0x90
iwl_pcie_irq_handler+0x92a/0x12f0 [iwlwifi]
irq_thread_fn+0x20/0x50
irq_thread+0x11f/0x150
kthread+0xd2/0xf0
ret_from_fork+0x42/0x70
} hitcount: 934 len: 5512212
Totals:
Hits: 1232
Entries: 4
Dropped: 0
The above shows all the netif_receive_skb callpaths and their total
lengths for the duration of the wget command.
The 'clear' hist trigger param can be used to clear the hash table.
Suppose we wanted to try another run of the previous example but
this time also wanted to see the complete list of events that went
into the histogram. In order to avoid having to set everything up
again, we can just clear the histogram first:
# echo 'hist:key=stacktrace:vals=len:clear' >> \
/sys/kernel/debug/tracing/events/net/netif_receive_skb/trigger
Just to verify that it is in fact cleared, here's what we now see in
the hist file:
# cat /sys/kernel/debug/tracing/events/net/netif_receive_skb/hist
# trigger info: hist:keys=stacktrace:vals=len:sort=hitcount:size=2048 [paused]
Totals:
Hits: 0
Entries: 0
Dropped: 0
Since we want to see the detailed list of every netif_receive_skb
event occurring during the new run, which are in fact the same
events being aggregated into the hash table, we add some additional
'enable_event' events to the triggering sched_process_exec and
sched_process_exit events as such:
# echo 'enable_event:net:netif_receive_skb if filename==/usr/bin/wget' > \
/sys/kernel/debug/tracing/events/sched/sched_process_exec/trigger
# echo 'disable_event:net:netif_receive_skb if comm==wget' > \
/sys/kernel/debug/tracing/events/sched/sched_process_exit/trigger
If you read the trigger files for the sched_process_exec and
sched_process_exit triggers, you should see two triggers for each:
one enabling/disabling the hist aggregation and the other
enabling/disabling the logging of events:
# cat /sys/kernel/debug/tracing/events/sched/sched_process_exec/trigger
enable_event:net:netif_receive_skb:unlimited if filename==/usr/bin/wget
enable_hist:net:netif_receive_skb:unlimited if filename==/usr/bin/wget
# cat /sys/kernel/debug/tracing/events/sched/sched_process_exit/trigger
enable_event:net:netif_receive_skb:unlimited if comm==wget
disable_hist:net:netif_receive_skb:unlimited if comm==wget
In other words, whenever either of the sched_process_exec or
sched_process_exit events is hit and matches 'wget', it enables or
disables both the histogram and the event log, and what you end up
with is a hash table and set of events just covering the specified
duration. Run the wget command again:
$ wget https://www.kernel.org/pub/linux/kernel/v3.x/patch-3.19.xz
Displaying the 'hist' file should show something similar to what you
saw in the last run, but this time you should also see the
individual events in the trace file:
# cat /sys/kernel/debug/tracing/trace
# tracer: nop
#
# entries-in-buffer/entries-written: 183/1426 #P:4
#
# _-----=> irqs-off
# / _----=> need-resched
# | / _---=> hardirq/softirq
# || / _--=> preempt-depth
# ||| / delay
# TASK-PID CPU# |||| TIMESTAMP FUNCTION
# | | | |||| | |
wget-15108 [000] ..s1 31769.606929: netif_receive_skb: dev=lo skbaddr=ffff88009c353100 len=60
wget-15108 [000] ..s1 31769.606999: netif_receive_skb: dev=lo skbaddr=ffff88009c353200 len=60
dnsmasq-1382 [000] ..s1 31769.677652: netif_receive_skb: dev=lo skbaddr=ffff88009c352b00 len=130
dnsmasq-1382 [000] ..s1 31769.685917: netif_receive_skb: dev=lo skbaddr=ffff88009c352200 len=138
##### CPU 2 buffer started ####
irq/29-iwlwifi-559 [002] ..s. 31772.031529: netif_receive_skb: dev=wlan0 skbaddr=ffff88009d433d00 len=2948
irq/29-iwlwifi-559 [002] ..s. 31772.031572: netif_receive_skb: dev=wlan0 skbaddr=ffff88009d432200 len=1500
irq/29-iwlwifi-559 [002] ..s. 31772.032196: netif_receive_skb: dev=wlan0 skbaddr=ffff88009d433100 len=2948
irq/29-iwlwifi-559 [002] ..s. 31772.032761: netif_receive_skb: dev=wlan0 skbaddr=ffff88009d433000 len=2948
irq/29-iwlwifi-559 [002] ..s. 31772.033220: netif_receive_skb: dev=wlan0 skbaddr=ffff88009d432e00 len=1500
.
.
.
The following example demonstrates how multiple hist triggers can be
attached to a given event. This capability can be useful for
creating a set of different summaries derived from the same set of
events, or for comparing the effects of different filters, among
other things.
# echo 'hist:keys=skbaddr.hex:vals=len if len < 0' >> \
/sys/kernel/debug/tracing/events/net/netif_receive_skb/trigger
# echo 'hist:keys=skbaddr.hex:vals=len if len > 4096' >> \
/sys/kernel/debug/tracing/events/net/netif_receive_skb/trigger
# echo 'hist:keys=skbaddr.hex:vals=len if len == 256' >> \
/sys/kernel/debug/tracing/events/net/netif_receive_skb/trigger
# echo 'hist:keys=skbaddr.hex:vals=len' >> \
/sys/kernel/debug/tracing/events/net/netif_receive_skb/trigger
# echo 'hist:keys=len:vals=common_preempt_count' >> \
/sys/kernel/debug/tracing/events/net/netif_receive_skb/trigger
The above set of commands create four triggers differing only in
their filters, along with a completely different though fairly
nonsensical trigger. Note that in order to append multiple hist
triggers to the same file, you should use the '>>' operator to
append them ('>' will also add the new hist trigger, but will remove
any existing hist triggers beforehand).
Displaying the contents of the 'hist' file for the event shows the
contents of all five histograms:
# cat /sys/kernel/debug/tracing/events/net/netif_receive_skb/hist
# event histogram
#
# trigger info: hist:keys=len:vals=hitcount,common_preempt_count:sort=hitcount:size=2048 [active]
#
{ len: 176 } hitcount: 1 common_preempt_count: 0
{ len: 223 } hitcount: 1 common_preempt_count: 0
{ len: 4854 } hitcount: 1 common_preempt_count: 0
{ len: 395 } hitcount: 1 common_preempt_count: 0
{ len: 177 } hitcount: 1 common_preempt_count: 0
{ len: 446 } hitcount: 1 common_preempt_count: 0
{ len: 1601 } hitcount: 1 common_preempt_count: 0
.
.
.
{ len: 1280 } hitcount: 66 common_preempt_count: 0
{ len: 116 } hitcount: 81 common_preempt_count: 40
{ len: 708 } hitcount: 112 common_preempt_count: 0
{ len: 46 } hitcount: 221 common_preempt_count: 0
{ len: 1264 } hitcount: 458 common_preempt_count: 0
Totals:
Hits: 1428
Entries: 147
Dropped: 0
# event histogram
#
# trigger info: hist:keys=skbaddr.hex:vals=hitcount,len:sort=hitcount:size=2048 [active]
#
{ skbaddr: ffff8800baee5e00 } hitcount: 1 len: 130
{ skbaddr: ffff88005f3d5600 } hitcount: 1 len: 1280
{ skbaddr: ffff88005f3d4900 } hitcount: 1 len: 1280
{ skbaddr: ffff88009fed6300 } hitcount: 1 len: 115
{ skbaddr: ffff88009fe0ad00 } hitcount: 1 len: 115
{ skbaddr: ffff88008cdb1900 } hitcount: 1 len: 46
{ skbaddr: ffff880064b5ef00 } hitcount: 1 len: 118
{ skbaddr: ffff880044e3c700 } hitcount: 1 len: 60
{ skbaddr: ffff880100065900 } hitcount: 1 len: 46
{ skbaddr: ffff8800d46bd500 } hitcount: 1 len: 116
{ skbaddr: ffff88005f3d5f00 } hitcount: 1 len: 1280
{ skbaddr: ffff880100064700 } hitcount: 1 len: 365
{ skbaddr: ffff8800badb6f00 } hitcount: 1 len: 60
.
.
.
{ skbaddr: ffff88009fe0be00 } hitcount: 27 len: 24677
{ skbaddr: ffff88009fe0a400 } hitcount: 27 len: 23052
{ skbaddr: ffff88009fe0b700 } hitcount: 31 len: 25589
{ skbaddr: ffff88009fe0b600 } hitcount: 32 len: 27326
{ skbaddr: ffff88006a462800 } hitcount: 68 len: 71678
{ skbaddr: ffff88006a463700 } hitcount: 70 len: 72678
{ skbaddr: ffff88006a462b00 } hitcount: 71 len: 77589
{ skbaddr: ffff88006a463600 } hitcount: 73 len: 71307
{ skbaddr: ffff88006a462200 } hitcount: 81 len: 81032
Totals:
Hits: 1451
Entries: 318
Dropped: 0
# event histogram
#
# trigger info: hist:keys=skbaddr.hex:vals=hitcount,len:sort=hitcount:size=2048 if len == 256 [active]
#
Totals:
Hits: 0
Entries: 0
Dropped: 0
# event histogram
#
# trigger info: hist:keys=skbaddr.hex:vals=hitcount,len:sort=hitcount:size=2048 if len > 4096 [active]
#
{ skbaddr: ffff88009fd2c300 } hitcount: 1 len: 7212
{ skbaddr: ffff8800d2bcce00 } hitcount: 1 len: 7212
{ skbaddr: ffff8800d2bcd700 } hitcount: 1 len: 7212
{ skbaddr: ffff8800d2bcda00 } hitcount: 1 len: 21492
{ skbaddr: ffff8800ae2e2d00 } hitcount: 1 len: 7212
{ skbaddr: ffff8800d2bcdb00 } hitcount: 1 len: 7212
{ skbaddr: ffff88006a4df500 } hitcount: 1 len: 4854
{ skbaddr: ffff88008ce47b00 } hitcount: 1 len: 18636
{ skbaddr: ffff8800ae2e2200 } hitcount: 1 len: 12924
{ skbaddr: ffff88005f3e1000 } hitcount: 1 len: 4356
{ skbaddr: ffff8800d2bcdc00 } hitcount: 2 len: 24420
{ skbaddr: ffff8800d2bcc200 } hitcount: 2 len: 12996
Totals:
Hits: 14
Entries: 12
Dropped: 0
# event histogram
#
# trigger info: hist:keys=skbaddr.hex:vals=hitcount,len:sort=hitcount:size=2048 if len < 0 [active]
#
Totals:
Hits: 0
Entries: 0
Dropped: 0
Named triggers can be used to have triggers share a common set of
histogram data. This capability is mostly useful for combining the
output of events generated by tracepoints contained inside inline
functions, but names can be used in a hist trigger on any event.
For example, these two triggers when hit will update the same 'len'
field in the shared 'foo' histogram data:
# echo 'hist:name=foo:keys=skbaddr.hex:vals=len' > \
/sys/kernel/debug/tracing/events/net/netif_receive_skb/trigger
# echo 'hist:name=foo:keys=skbaddr.hex:vals=len' > \
/sys/kernel/debug/tracing/events/net/netif_rx/trigger
You can see that they're updating common histogram data by reading
each event's hist files at the same time:
# cat /sys/kernel/debug/tracing/events/net/netif_receive_skb/hist;
cat /sys/kernel/debug/tracing/events/net/netif_rx/hist
# event histogram
#
# trigger info: hist:name=foo:keys=skbaddr.hex:vals=hitcount,len:sort=hitcount:size=2048 [active]
#
{ skbaddr: ffff88000ad53500 } hitcount: 1 len: 46
{ skbaddr: ffff8800af5a1500 } hitcount: 1 len: 76
{ skbaddr: ffff8800d62a1900 } hitcount: 1 len: 46
{ skbaddr: ffff8800d2bccb00 } hitcount: 1 len: 468
{ skbaddr: ffff8800d3c69900 } hitcount: 1 len: 46
{ skbaddr: ffff88009ff09100 } hitcount: 1 len: 52
{ skbaddr: ffff88010f13ab00 } hitcount: 1 len: 168
{ skbaddr: ffff88006a54f400 } hitcount: 1 len: 46
{ skbaddr: ffff8800d2bcc500 } hitcount: 1 len: 260
{ skbaddr: ffff880064505000 } hitcount: 1 len: 46
{ skbaddr: ffff8800baf24e00 } hitcount: 1 len: 32
{ skbaddr: ffff88009fe0ad00 } hitcount: 1 len: 46
{ skbaddr: ffff8800d3edff00 } hitcount: 1 len: 44
{ skbaddr: ffff88009fe0b400 } hitcount: 1 len: 168
{ skbaddr: ffff8800a1c55a00 } hitcount: 1 len: 40
{ skbaddr: ffff8800d2bcd100 } hitcount: 1 len: 40
{ skbaddr: ffff880064505f00 } hitcount: 1 len: 174
{ skbaddr: ffff8800a8bff200 } hitcount: 1 len: 160
{ skbaddr: ffff880044e3cc00 } hitcount: 1 len: 76
{ skbaddr: ffff8800a8bfe700 } hitcount: 1 len: 46
{ skbaddr: ffff8800d2bcdc00 } hitcount: 1 len: 32
{ skbaddr: ffff8800a1f64800 } hitcount: 1 len: 46
{ skbaddr: ffff8800d2bcde00 } hitcount: 1 len: 988
{ skbaddr: ffff88006a5dea00 } hitcount: 1 len: 46
{ skbaddr: ffff88002e37a200 } hitcount: 1 len: 44
{ skbaddr: ffff8800a1f32c00 } hitcount: 2 len: 676
{ skbaddr: ffff88000ad52600 } hitcount: 2 len: 107
{ skbaddr: ffff8800a1f91e00 } hitcount: 2 len: 92
{ skbaddr: ffff8800af5a0200 } hitcount: 2 len: 142
{ skbaddr: ffff8800d2bcc600 } hitcount: 2 len: 220
{ skbaddr: ffff8800ba36f500 } hitcount: 2 len: 92
{ skbaddr: ffff8800d021f800 } hitcount: 2 len: 92
{ skbaddr: ffff8800a1f33600 } hitcount: 2 len: 675
{ skbaddr: ffff8800a8bfff00 } hitcount: 3 len: 138
{ skbaddr: ffff8800d62a1300 } hitcount: 3 len: 138
{ skbaddr: ffff88002e37a100 } hitcount: 4 len: 184
{ skbaddr: ffff880064504400 } hitcount: 4 len: 184
{ skbaddr: ffff8800a8bfec00 } hitcount: 4 len: 184
{ skbaddr: ffff88000ad53700 } hitcount: 5 len: 230
{ skbaddr: ffff8800d2bcdb00 } hitcount: 5 len: 196
{ skbaddr: ffff8800a1f90000 } hitcount: 6 len: 276
{ skbaddr: ffff88006a54f900 } hitcount: 6 len: 276
Totals:
Hits: 81
Entries: 42
Dropped: 0
# event histogram
#
# trigger info: hist:name=foo:keys=skbaddr.hex:vals=hitcount,len:sort=hitcount:size=2048 [active]
#
{ skbaddr: ffff88000ad53500 } hitcount: 1 len: 46
{ skbaddr: ffff8800af5a1500 } hitcount: 1 len: 76
{ skbaddr: ffff8800d62a1900 } hitcount: 1 len: 46
{ skbaddr: ffff8800d2bccb00 } hitcount: 1 len: 468
{ skbaddr: ffff8800d3c69900 } hitcount: 1 len: 46
{ skbaddr: ffff88009ff09100 } hitcount: 1 len: 52
{ skbaddr: ffff88010f13ab00 } hitcount: 1 len: 168
{ skbaddr: ffff88006a54f400 } hitcount: 1 len: 46
{ skbaddr: ffff8800d2bcc500 } hitcount: 1 len: 260
{ skbaddr: ffff880064505000 } hitcount: 1 len: 46
{ skbaddr: ffff8800baf24e00 } hitcount: 1 len: 32
{ skbaddr: ffff88009fe0ad00 } hitcount: 1 len: 46
{ skbaddr: ffff8800d3edff00 } hitcount: 1 len: 44
{ skbaddr: ffff88009fe0b400 } hitcount: 1 len: 168
{ skbaddr: ffff8800a1c55a00 } hitcount: 1 len: 40
{ skbaddr: ffff8800d2bcd100 } hitcount: 1 len: 40
{ skbaddr: ffff880064505f00 } hitcount: 1 len: 174
{ skbaddr: ffff8800a8bff200 } hitcount: 1 len: 160
{ skbaddr: ffff880044e3cc00 } hitcount: 1 len: 76
{ skbaddr: ffff8800a8bfe700 } hitcount: 1 len: 46
{ skbaddr: ffff8800d2bcdc00 } hitcount: 1 len: 32
{ skbaddr: ffff8800a1f64800 } hitcount: 1 len: 46
{ skbaddr: ffff8800d2bcde00 } hitcount: 1 len: 988
{ skbaddr: ffff88006a5dea00 } hitcount: 1 len: 46
{ skbaddr: ffff88002e37a200 } hitcount: 1 len: 44
{ skbaddr: ffff8800a1f32c00 } hitcount: 2 len: 676
{ skbaddr: ffff88000ad52600 } hitcount: 2 len: 107
{ skbaddr: ffff8800a1f91e00 } hitcount: 2 len: 92
{ skbaddr: ffff8800af5a0200 } hitcount: 2 len: 142
{ skbaddr: ffff8800d2bcc600 } hitcount: 2 len: 220
{ skbaddr: ffff8800ba36f500 } hitcount: 2 len: 92
{ skbaddr: ffff8800d021f800 } hitcount: 2 len: 92
{ skbaddr: ffff8800a1f33600 } hitcount: 2 len: 675
{ skbaddr: ffff8800a8bfff00 } hitcount: 3 len: 138
{ skbaddr: ffff8800d62a1300 } hitcount: 3 len: 138
{ skbaddr: ffff88002e37a100 } hitcount: 4 len: 184
{ skbaddr: ffff880064504400 } hitcount: 4 len: 184
{ skbaddr: ffff8800a8bfec00 } hitcount: 4 len: 184
{ skbaddr: ffff88000ad53700 } hitcount: 5 len: 230
{ skbaddr: ffff8800d2bcdb00 } hitcount: 5 len: 196
{ skbaddr: ffff8800a1f90000 } hitcount: 6 len: 276
{ skbaddr: ffff88006a54f900 } hitcount: 6 len: 276
Totals:
Hits: 81
Entries: 42
Dropped: 0
And here's an example that shows how to combine histogram data from
any two events even if they don't share any 'compatible' fields
other than 'hitcount' and 'stacktrace'. These commands create a
couple of triggers named 'bar' using those fields:
# echo 'hist:name=bar:key=stacktrace:val=hitcount' > \
/sys/kernel/debug/tracing/events/sched/sched_process_fork/trigger
# echo 'hist:name=bar:key=stacktrace:val=hitcount' > \
/sys/kernel/debug/tracing/events/net/netif_rx/trigger
And displaying the output of either shows some interesting if
somewhat confusing output:
# cat /sys/kernel/debug/tracing/events/sched/sched_process_fork/hist
# cat /sys/kernel/debug/tracing/events/net/netif_rx/hist
# event histogram
#
# trigger info: hist:name=bar:keys=stacktrace:vals=hitcount:sort=hitcount:size=2048 [active]
#
{ stacktrace:
_do_fork+0x18e/0x330
kernel_thread+0x29/0x30
kthreadd+0x154/0x1b0
ret_from_fork+0x3f/0x70
} hitcount: 1
{ stacktrace:
netif_rx_internal+0xb2/0xd0
netif_rx_ni+0x20/0x70
dev_loopback_xmit+0xaa/0xd0
ip_mc_output+0x126/0x240
ip_local_out_sk+0x31/0x40
igmp_send_report+0x1e9/0x230
igmp_timer_expire+0xe9/0x120
call_timer_fn+0x39/0xf0
run_timer_softirq+0x1e1/0x290
__do_softirq+0xfd/0x290
irq_exit+0x98/0xb0
smp_apic_timer_interrupt+0x4a/0x60
apic_timer_interrupt+0x6d/0x80
cpuidle_enter+0x17/0x20
call_cpuidle+0x3b/0x60
cpu_startup_entry+0x22d/0x310
} hitcount: 1
{ stacktrace:
netif_rx_internal+0xb2/0xd0
netif_rx_ni+0x20/0x70
dev_loopback_xmit+0xaa/0xd0
ip_mc_output+0x17f/0x240
ip_local_out_sk+0x31/0x40
ip_send_skb+0x1a/0x50
udp_send_skb+0x13e/0x270
udp_sendmsg+0x2bf/0x980
inet_sendmsg+0x67/0xa0
sock_sendmsg+0x38/0x50
SYSC_sendto+0xef/0x170
SyS_sendto+0xe/0x10
entry_SYSCALL_64_fastpath+0x12/0x6a
} hitcount: 2
{ stacktrace:
netif_rx_internal+0xb2/0xd0
netif_rx+0x1c/0x60
loopback_xmit+0x6c/0xb0
dev_hard_start_xmit+0x219/0x3a0
__dev_queue_xmit+0x415/0x4f0
dev_queue_xmit_sk+0x13/0x20
ip_finish_output2+0x237/0x340
ip_finish_output+0x113/0x1d0
ip_output+0x66/0xc0
ip_local_out_sk+0x31/0x40
ip_send_skb+0x1a/0x50
udp_send_skb+0x16d/0x270
udp_sendmsg+0x2bf/0x980
inet_sendmsg+0x67/0xa0
sock_sendmsg+0x38/0x50
___sys_sendmsg+0x14e/0x270
} hitcount: 76
{ stacktrace:
netif_rx_internal+0xb2/0xd0
netif_rx+0x1c/0x60
loopback_xmit+0x6c/0xb0
dev_hard_start_xmit+0x219/0x3a0
__dev_queue_xmit+0x415/0x4f0
dev_queue_xmit_sk+0x13/0x20
ip_finish_output2+0x237/0x340
ip_finish_output+0x113/0x1d0
ip_output+0x66/0xc0
ip_local_out_sk+0x31/0x40
ip_send_skb+0x1a/0x50
udp_send_skb+0x16d/0x270
udp_sendmsg+0x2bf/0x980
inet_sendmsg+0x67/0xa0
sock_sendmsg+0x38/0x50
___sys_sendmsg+0x269/0x270
} hitcount: 77
{ stacktrace:
netif_rx_internal+0xb2/0xd0
netif_rx+0x1c/0x60
loopback_xmit+0x6c/0xb0
dev_hard_start_xmit+0x219/0x3a0
__dev_queue_xmit+0x415/0x4f0
dev_queue_xmit_sk+0x13/0x20
ip_finish_output2+0x237/0x340
ip_finish_output+0x113/0x1d0
ip_output+0x66/0xc0
ip_local_out_sk+0x31/0x40
ip_send_skb+0x1a/0x50
udp_send_skb+0x16d/0x270
udp_sendmsg+0x2bf/0x980
inet_sendmsg+0x67/0xa0
sock_sendmsg+0x38/0x50
SYSC_sendto+0xef/0x170
} hitcount: 88
{ stacktrace:
_do_fork+0x18e/0x330
SyS_clone+0x19/0x20
entry_SYSCALL_64_fastpath+0x12/0x6a
} hitcount: 244
Totals:
Hits: 489
Entries: 7
Dropped: 0
Documentation/trace/ftrace.txt
View file @ 2600a46e
......@@ -210,6 +210,11 @@ of ftrace. Here is a list of some of the key files:
Note, sched_switch and sched_wake_up will also trace events
listed in this file.
To have the PIDs of children of tasks with their PID in this file
added on fork, enable the "event-fork" option. That option will also
cause the PIDs of tasks to be removed from this file when the task
exits.
set_graph_function:
Set a "trigger" function where tracing should start
......@@ -725,16 +730,14 @@ noraw
nohex
nobin
noblock
nostacktrace
trace_printk
noftrace_preempt
nobranch
annotate
nouserstacktrace
nosym-userobj
noprintk-msg-only
context-info
latency-format
nolatency-format
sleep-time
graph-time
record-cmd
......@@ -742,7 +745,10 @@ overwrite
nodisable_on_free
irq-info
markers
noevent-fork
function-trace
nodisplay-graph
nostacktrace
To disable one of the options, echo in the option prepended with
"no".
......@@ -796,11 +802,6 @@ Here are the available options:
block - When set, reading trace_pipe will not block when polled.
stacktrace - This is one of the options that changes the trace
itself. When a trace is recorded, so is the stack
of functions. This allows for back traces of
trace sites.
trace_printk - Can disable trace_printk() from writing into the buffer.
branch - Enable branch tracing with the tracer.
......@@ -897,6 +898,10 @@ x494] <- /root/a.out[+0x4a8] <- /lib/libc-2.7.so[+0x1e1a6]
When disabled, the trace_marker will error with EINVAL
on write.
event-fork - When set, tasks with PIDs listed in set_event_pid will have
the PIDs of their children added to set_event_pid when those
tasks fork. Also, when tasks with PIDs in set_event_pid exit,
their PIDs will be removed from the file.
function-trace - The latency tracers will enable function tracing
if this option is enabled (default it is). When
......@@ -904,8 +909,17 @@ x494] <- /root/a.out[+0x4a8] <- /lib/libc-2.7.so[+0x1e1a6]
functions. This keeps the overhead of the tracer down
when performing latency tests.
Note: Some tracers have their own options. They only appear
when the tracer is active.
display-graph - When set, the latency tracers (irqsoff, wakeup, etc) will
use function graph tracing instead of function tracing.
stacktrace - This is one of the options that changes the trace
itself. When a trace is recorded, so is the stack
of functions. This allows for back traces of
trace sites.
Note: Some tracers have their own options. They only appear in this
file when the tracer is active. They always appear in the
options directory.
......
include/linux/trace_events.h
View file @ 2600a46e
......@@ -154,21 +154,6 @@ trace_event_buffer_lock_reserve(struct ring_buffer **current_buffer,
struct trace_event_file *trace_file,
int type, unsigned long len,
unsigned long flags, int pc);
struct ring_buffer_event *
trace_current_buffer_lock_reserve(struct ring_buffer **current_buffer,
int type, unsigned long len,
unsigned long flags, int pc);
void trace_buffer_unlock_commit(struct trace_array *tr,
struct ring_buffer *buffer,
struct ring_buffer_event *event,
unsigned long flags, int pc);
void trace_buffer_unlock_commit_regs(struct trace_array *tr,
struct ring_buffer *buffer,
struct ring_buffer_event *event,
unsigned long flags, int pc,
struct pt_regs *regs);
void trace_current_buffer_discard_commit(struct ring_buffer *buffer,
struct ring_buffer_event *event);
void tracing_record_cmdline(struct task_struct *tsk);
......@@ -229,7 +214,6 @@ enum {
TRACE_EVENT_FL_NO_SET_FILTER_BIT,
TRACE_EVENT_FL_IGNORE_ENABLE_BIT,
TRACE_EVENT_FL_WAS_ENABLED_BIT,
TRACE_EVENT_FL_USE_CALL_FILTER_BIT,
TRACE_EVENT_FL_TRACEPOINT_BIT,
TRACE_EVENT_FL_KPROBE_BIT,
TRACE_EVENT_FL_UPROBE_BIT,
......@@ -244,7 +228,6 @@ enum {
* WAS_ENABLED - Set and stays set when an event was ever enabled
* (used for module unloading, if a module event is enabled,
* it is best to clear the buffers that used it).
* USE_CALL_FILTER - For trace internal events, don't use file filter
* TRACEPOINT - Event is a tracepoint
* KPROBE - Event is a kprobe
* UPROBE - Event is a uprobe
......@@ -255,7 +238,6 @@ enum {
TRACE_EVENT_FL_NO_SET_FILTER = (1 << TRACE_EVENT_FL_NO_SET_FILTER_BIT),
TRACE_EVENT_FL_IGNORE_ENABLE = (1 << TRACE_EVENT_FL_IGNORE_ENABLE_BIT),
TRACE_EVENT_FL_WAS_ENABLED = (1 << TRACE_EVENT_FL_WAS_ENABLED_BIT),
TRACE_EVENT_FL_USE_CALL_FILTER = (1 << TRACE_EVENT_FL_USE_CALL_FILTER_BIT),
TRACE_EVENT_FL_TRACEPOINT = (1 << TRACE_EVENT_FL_TRACEPOINT_BIT),
TRACE_EVENT_FL_KPROBE = (1 << TRACE_EVENT_FL_KPROBE_BIT),
TRACE_EVENT_FL_UPROBE = (1 << TRACE_EVENT_FL_UPROBE_BIT),
......@@ -407,16 +389,12 @@ enum event_trigger_type {
ETT_SNAPSHOT = (1 << 1),
ETT_STACKTRACE = (1 << 2),
ETT_EVENT_ENABLE = (1 << 3),
ETT_EVENT_HIST = (1 << 4),
ETT_HIST_ENABLE = (1 << 5),
};
extern int filter_match_preds(struct event_filter *filter, void *rec);
extern int filter_check_discard(struct trace_event_file *file, void *rec,
struct ring_buffer *buffer,
struct ring_buffer_event *event);
extern int call_filter_check_discard(struct trace_event_call *call, void *rec,
struct ring_buffer *buffer,
struct ring_buffer_event *event);
extern enum event_trigger_type event_triggers_call(struct trace_event_file *file,
void *rec);
extern void event_triggers_post_call(struct trace_event_file *file,
......@@ -450,100 +428,6 @@ trace_trigger_soft_disabled(struct trace_event_file *file)
return false;
}
/*
* Helper function for event_trigger_unlock_commit{_regs}().
* If there are event triggers attached to this event that requires
* filtering against its fields, then they wil be called as the
* entry already holds the field information of the current event.
*
* It also checks if the event should be discarded or not.
* It is to be discarded if the event is soft disabled and the
* event was only recorded to process triggers, or if the event
* filter is active and this event did not match the filters.
*
* Returns true if the event is discarded, false otherwise.
*/
static inline bool
__event_trigger_test_discard(struct trace_event_file *file,
struct ring_buffer *buffer,
struct ring_buffer_event *event,
void *entry,
enum event_trigger_type *tt)
{
unsigned long eflags = file->flags;
if (eflags & EVENT_FILE_FL_TRIGGER_COND)
*tt = event_triggers_call(file, entry);
if (test_bit(EVENT_FILE_FL_SOFT_DISABLED_BIT, &file->flags))
ring_buffer_discard_commit(buffer, event);
else if (!filter_check_discard(file, entry, buffer, event))
return false;
return true;
}
/**
* event_trigger_unlock_commit - handle triggers and finish event commit
* @file: The file pointer assoctiated to the event
* @buffer: The ring buffer that the event is being written to
* @event: The event meta data in the ring buffer
* @entry: The event itself
* @irq_flags: The state of the interrupts at the start of the event
* @pc: The state of the preempt count at the start of the event.
*
* This is a helper function to handle triggers that require data
* from the event itself. It also tests the event against filters and
* if the event is soft disabled and should be discarded.
*/
static inline void
event_trigger_unlock_commit(struct trace_event_file *file,
struct ring_buffer *buffer,
struct ring_buffer_event *event,
void *entry, unsigned long irq_flags, int pc)
{
enum event_trigger_type tt = ETT_NONE;
if (!__event_trigger_test_discard(file, buffer, event, entry, &tt))
trace_buffer_unlock_commit(file->tr, buffer, event, irq_flags, pc);
if (tt)
event_triggers_post_call(file, tt, entry);
}
/**
* event_trigger_unlock_commit_regs - handle triggers and finish event commit
* @file: The file pointer assoctiated to the event
* @buffer: The ring buffer that the event is being written to
* @event: The event meta data in the ring buffer
* @entry: The event itself
* @irq_flags: The state of the interrupts at the start of the event
* @pc: The state of the preempt count at the start of the event.
*
* This is a helper function to handle triggers that require data
* from the event itself. It also tests the event against filters and
* if the event is soft disabled and should be discarded.
*
* Same as event_trigger_unlock_commit() but calls
* trace_buffer_unlock_commit_regs() instead of trace_buffer_unlock_commit().
*/
static inline void
event_trigger_unlock_commit_regs(struct trace_event_file *file,
struct ring_buffer *buffer,
struct ring_buffer_event *event,
void *entry, unsigned long irq_flags, int pc,
struct pt_regs *regs)
{
enum event_trigger_type tt = ETT_NONE;
if (!__event_trigger_test_discard(file, buffer, event, entry, &tt))
trace_buffer_unlock_commit_regs(file->tr, buffer, event,
irq_flags, pc, regs);
if (tt)
event_triggers_post_call(file, tt, entry);
}
#ifdef CONFIG_BPF_EVENTS
unsigned int trace_call_bpf(struct bpf_prog *prog, void *ctx);
#else
......
kernel/trace/Kconfig
View file @ 2600a46e
......@@ -528,6 +528,32 @@ config MMIOTRACE
See Documentation/trace/mmiotrace.txt.
If you are not helping to develop drivers, say N.
config TRACING_MAP
bool
depends on ARCH_HAVE_NMI_SAFE_CMPXCHG
help
tracing_map is a special-purpose lock-free map for tracing,
separated out as a stand-alone facility in order to allow it
to be shared between multiple tracers. It isn't meant to be
generally used outside of that context, and is normally
selected by tracers that use it.
config HIST_TRIGGERS
bool "Histogram triggers"
depends on ARCH_HAVE_NMI_SAFE_CMPXCHG
select TRACING_MAP
default n
help
Hist triggers allow one or more arbitrary trace event fields
to be aggregated into hash tables and dumped to stdout by
reading a debugfs/tracefs file. They're useful for
gathering quick and dirty (though precise) summaries of
event activity as an initial guide for further investigation
using more advanced tools.
See Documentation/trace/events.txt.
If in doubt, say N.
config MMIOTRACE_TEST
tristate "Test module for mmiotrace"
depends on MMIOTRACE && m
......
kernel/trace/Makefile
View file @ 2600a46e
......@@ -31,6 +31,7 @@ obj-$(CONFIG_TRACING) += trace_output.o
obj-$(CONFIG_TRACING) += trace_seq.o
obj-$(CONFIG_TRACING) += trace_stat.o
obj-$(CONFIG_TRACING) += trace_printk.o
obj-$(CONFIG_TRACING_MAP) += tracing_map.o
obj-$(CONFIG_CONTEXT_SWITCH_TRACER) += trace_sched_switch.o
obj-$(CONFIG_FUNCTION_TRACER) += trace_functions.o
obj-$(CONFIG_IRQSOFF_TRACER) += trace_irqsoff.o
......@@ -53,6 +54,7 @@ obj-$(CONFIG_EVENT_TRACING) += trace_event_perf.o
endif
obj-$(CONFIG_EVENT_TRACING) += trace_events_filter.o
obj-$(CONFIG_EVENT_TRACING) += trace_events_trigger.o
obj-$(CONFIG_HIST_TRIGGERS) += trace_events_hist.o
obj-$(CONFIG_BPF_EVENTS) += bpf_trace.o
obj-$(CONFIG_KPROBE_EVENT) += trace_kprobe.o
obj-$(CONFIG_TRACEPOINTS) += power-traces.o
......
kernel/trace/trace.c
View file @ 2600a46e
......@@ -253,6 +253,9 @@ unsigned long long ns2usecs(cycle_t nsec)
#define TOP_LEVEL_TRACE_FLAGS (TRACE_ITER_PRINTK | \
TRACE_ITER_PRINTK_MSGONLY | TRACE_ITER_RECORD_CMD)
/* trace_flags that are default zero for instances */
#define ZEROED_TRACE_FLAGS \
TRACE_ITER_EVENT_FORK
/*
* The global_trace is the descriptor that holds the tracing
......@@ -303,33 +306,18 @@ void trace_array_put(struct trace_array *this_tr)
mutex_unlock(&trace_types_lock);
}
int filter_check_discard(struct trace_event_file *file, void *rec,
struct ring_buffer *buffer,
struct ring_buffer_event *event)
{
if (unlikely(file->flags & EVENT_FILE_FL_FILTERED) &&
!filter_match_preds(file->filter, rec)) {
ring_buffer_discard_commit(buffer, event);
return 1;
}
return 0;
}
EXPORT_SYMBOL_GPL(filter_check_discard);
int call_filter_check_discard(struct trace_event_call *call, void *rec,
struct ring_buffer *buffer,
struct ring_buffer_event *event)
{
if (unlikely(call->flags & TRACE_EVENT_FL_FILTERED) &&
!filter_match_preds(call->filter, rec)) {
ring_buffer_discard_commit(buffer, event);
__trace_event_discard_commit(buffer, event);
return 1;
}
return 0;
}
EXPORT_SYMBOL_GPL(call_filter_check_discard);
static cycle_t buffer_ftrace_now(struct trace_buffer *buf, int cpu)
{
......@@ -1672,6 +1660,16 @@ tracing_generic_entry_update(struct trace_entry *entry, unsigned long flags,
}
EXPORT_SYMBOL_GPL(tracing_generic_entry_update);
static __always_inline void
trace_event_setup(struct ring_buffer_event *event,
int type, unsigned long flags, int pc)
{
struct trace_entry *ent = ring_buffer_event_data(event);
tracing_generic_entry_update(ent, flags, pc);
ent->type = type;
}
struct ring_buffer_event *
trace_buffer_lock_reserve(struct ring_buffer *buffer,
int type,
......@@ -1681,34 +1679,137 @@ trace_buffer_lock_reserve(struct ring_buffer *buffer,
struct ring_buffer_event *event;
event = ring_buffer_lock_reserve(buffer, len);
if (event != NULL) {
struct trace_entry *ent = ring_buffer_event_data(event);
if (event != NULL)
trace_event_setup(event, type, flags, pc);
return event;
}
DEFINE_PER_CPU(struct ring_buffer_event *, trace_buffered_event);
DEFINE_PER_CPU(int, trace_buffered_event_cnt);
static int trace_buffered_event_ref;
/**
* trace_buffered_event_enable - enable buffering events
*
* When events are being filtered, it is quicker to use a temporary
* buffer to write the event data into if there's a likely chance
* that it will not be committed. The discard of the ring buffer
* is not as fast as committing, and is much slower than copying
* a commit.
*
* When an event is to be filtered, allocate per cpu buffers to
* write the event data into, and if the event is filtered and discarded
* it is simply dropped, otherwise, the entire data is to be committed
* in one shot.
*/
void trace_buffered_event_enable(void)
{
struct ring_buffer_event *event;
struct page *page;
int cpu;
tracing_generic_entry_update(ent, flags, pc);
ent->type = type;
WARN_ON_ONCE(!mutex_is_locked(&event_mutex));
if (trace_buffered_event_ref++)
return;
for_each_tracing_cpu(cpu) {
page = alloc_pages_node(cpu_to_node(cpu),
GFP_KERNEL | __GFP_NORETRY, 0);
if (!page)
goto failed;
event = page_address(page);
memset(event, 0, sizeof(*event));
per_cpu(trace_buffered_event, cpu) = event;
preempt_disable();
if (cpu == smp_processor_id() &&
this_cpu_read(trace_buffered_event) !=
per_cpu(trace_buffered_event, cpu))
WARN_ON_ONCE(1);
preempt_enable();
}
return event;
return;
failed:
trace_buffered_event_disable();
}
void
__buffer_unlock_commit(struct ring_buffer *buffer, struct ring_buffer_event *event)
static void enable_trace_buffered_event(void *data)
{
__this_cpu_write(trace_cmdline_save, true);
ring_buffer_unlock_commit(buffer, event);
/* Probably not needed, but do it anyway */
smp_rmb();
this_cpu_dec(trace_buffered_event_cnt);
}
void trace_buffer_unlock_commit(struct trace_array *tr,
struct ring_buffer *buffer,
struct ring_buffer_event *event,
unsigned long flags, int pc)
static void disable_trace_buffered_event(void *data)
{
__buffer_unlock_commit(buffer, event);
this_cpu_inc(trace_buffered_event_cnt);
}
ftrace_trace_stack(tr, buffer, flags, 6, pc, NULL);
ftrace_trace_userstack(buffer, flags, pc);
/**
* trace_buffered_event_disable - disable buffering events
*
* When a filter is removed, it is faster to not use the buffered
* events, and to commit directly into the ring buffer. Free up
* the temp buffers when there are no more users. This requires
* special synchronization with current events.
*/
void trace_buffered_event_disable(void)
{
int cpu;
WARN_ON_ONCE(!mutex_is_locked(&event_mutex));
if (WARN_ON_ONCE(!trace_buffered_event_ref))
return;
if (--trace_buffered_event_ref)
return;
preempt_disable();
/* For each CPU, set the buffer as used. */
smp_call_function_many(tracing_buffer_mask,
disable_trace_buffered_event, NULL, 1);
preempt_enable();
/* Wait for all current users to finish */
synchronize_sched();
for_each_tracing_cpu(cpu) {
free_page((unsigned long)per_cpu(trace_buffered_event, cpu));
per_cpu(trace_buffered_event, cpu) = NULL;
}
/*
* Make sure trace_buffered_event is NULL before clearing
* trace_buffered_event_cnt.
*/
smp_wmb();
preempt_disable();
/* Do the work on each cpu */
smp_call_function_many(tracing_buffer_mask,
enable_trace_buffered_event, NULL, 1);
preempt_enable();
}
void
__buffer_unlock_commit(struct ring_buffer *buffer, struct ring_buffer_event *event)
{
__this_cpu_write(trace_cmdline_save, true);
/* If this is the temp buffer, we need to commit fully */
if (this_cpu_read(trace_buffered_event) == event) {
/* Length is in event->array[0] */
ring_buffer_write(buffer, event->array[0], &event->array[1]);
/* Release the temp buffer */
this_cpu_dec(trace_buffered_event_cnt);
} else
ring_buffer_unlock_commit(buffer, event);
}
EXPORT_SYMBOL_GPL(trace_buffer_unlock_commit);
static struct ring_buffer *temp_buffer;
......@@ -1719,8 +1820,23 @@ trace_event_buffer_lock_reserve(struct ring_buffer **current_rb,
unsigned long flags, int pc)
{
struct ring_buffer_event *entry;
int val;
*current_rb = trace_file->tr->trace_buffer.buffer;
if ((trace_file->flags &
(EVENT_FILE_FL_SOFT_DISABLED | EVENT_FILE_FL_FILTERED)) &&
(entry = this_cpu_read(trace_buffered_event))) {
/* Try to use the per cpu buffer first */
val = this_cpu_inc_return(trace_buffered_event_cnt);
if (val == 1) {
trace_event_setup(entry, type, flags, pc);
entry->array[0] = len;
return entry;
}
this_cpu_dec(trace_buffered_event_cnt);
}
entry = trace_buffer_lock_reserve(*current_rb,
type, len, flags, pc);
/*
......@@ -1738,17 +1854,6 @@ trace_event_buffer_lock_reserve(struct ring_buffer **current_rb,
}
EXPORT_SYMBOL_GPL(trace_event_buffer_lock_reserve);
struct ring_buffer_event *
trace_current_buffer_lock_reserve(struct ring_buffer **current_rb,
int type, unsigned long len,
unsigned long flags, int pc)
{
*current_rb = global_trace.trace_buffer.buffer;
return trace_buffer_lock_reserve(*current_rb,
type, len, flags, pc);
}
EXPORT_SYMBOL_GPL(trace_current_buffer_lock_reserve);
void trace_buffer_unlock_commit_regs(struct trace_array *tr,
struct ring_buffer *buffer,
struct ring_buffer_event *event,
......@@ -1760,14 +1865,6 @@ void trace_buffer_unlock_commit_regs(struct trace_array *tr,
ftrace_trace_stack(tr, buffer, flags, 0, pc, regs);
ftrace_trace_userstack(buffer, flags, pc);
}
EXPORT_SYMBOL_GPL(trace_buffer_unlock_commit_regs);
void trace_current_buffer_discard_commit(struct ring_buffer *buffer,
struct ring_buffer_event *event)
{
ring_buffer_discard_commit(buffer, event);
}
EXPORT_SYMBOL_GPL(trace_current_buffer_discard_commit);
void
trace_function(struct trace_array *tr,
......@@ -3571,6 +3668,9 @@ int set_tracer_flag(struct trace_array *tr, unsigned int mask, int enabled)
if (mask == TRACE_ITER_RECORD_CMD)
trace_event_enable_cmd_record(enabled);
if (mask == TRACE_ITER_EVENT_FORK)
trace_event_follow_fork(tr, enabled);
if (mask == TRACE_ITER_OVERWRITE) {
ring_buffer_change_overwrite(tr->trace_buffer.buffer, enabled);
#ifdef CONFIG_TRACER_MAX_TRACE
......@@ -3658,7 +3758,7 @@ tracing_trace_options_write(struct file *filp, const char __user *ubuf,
if (cnt >= sizeof(buf))
return -EINVAL;
if (copy_from_user(&buf, ubuf, cnt))
if (copy_from_user(buf, ubuf, cnt))
return -EFAULT;
buf[cnt] = 0;
......@@ -3804,11 +3904,18 @@ static const char readme_msg[] =
"\t trigger: traceon, traceoff\n"
"\t enable_event:<system>:<event>\n"
"\t disable_event:<system>:<event>\n"
#ifdef CONFIG_HIST_TRIGGERS
"\t enable_hist:<system>:<event>\n"
"\t disable_hist:<system>:<event>\n"
#endif
#ifdef CONFIG_STACKTRACE
"\t\t stacktrace\n"
#endif
#ifdef CONFIG_TRACER_SNAPSHOT
"\t\t snapshot\n"
#endif
#ifdef CONFIG_HIST_TRIGGERS
"\t\t hist (see below)\n"
#endif
"\t example: echo traceoff > events/block/block_unplug/trigger\n"
"\t echo traceoff:3 > events/block/block_unplug/trigger\n"
......@@ -3825,6 +3932,56 @@ static const char readme_msg[] =
"\t To remove a trigger with a count:\n"
"\t echo '!<trigger>:0 > <system>/<event>/trigger\n"
"\t Filters can be ignored when removing a trigger.\n"
#ifdef CONFIG_HIST_TRIGGERS
" hist trigger\t- If set, event hits are aggregated into a hash table\n"
"\t Format: hist:keys=<field1[,field2,...]>\n"
"\t [:values=<field1[,field2,...]>]\n"
"\t [:sort=<field1[,field2,...]>]\n"
"\t [:size=#entries]\n"
"\t [:pause][:continue][:clear]\n"
"\t [:name=histname1]\n"
"\t [if <filter>]\n\n"
"\t When a matching event is hit, an entry is added to a hash\n"
"\t table using the key(s) and value(s) named, and the value of a\n"
"\t sum called 'hitcount' is incremented. Keys and values\n"
"\t correspond to fields in the event's format description. Keys\n"
"\t can be any field, or the special string 'stacktrace'.\n"
"\t Compound keys consisting of up to two fields can be specified\n"
"\t by the 'keys' keyword. Values must correspond to numeric\n"
"\t fields. Sort keys consisting of up to two fields can be\n"
"\t specified using the 'sort' keyword. The sort direction can\n"
"\t be modified by appending '.descending' or '.ascending' to a\n"
"\t sort field. The 'size' parameter can be used to specify more\n"
"\t or fewer than the default 2048 entries for the hashtable size.\n"
"\t If a hist trigger is given a name using the 'name' parameter,\n"
"\t its histogram data will be shared with other triggers of the\n"
"\t same name, and trigger hits will update this common data.\n\n"
"\t Reading the 'hist' file for the event will dump the hash\n"
"\t table in its entirety to stdout. If there are multiple hist\n"
"\t triggers attached to an event, there will be a table for each\n"
"\t trigger in the output. The table displayed for a named\n"
"\t trigger will be the same as any other instance having the\n"
"\t same name. The default format used to display a given field\n"
"\t can be modified by appending any of the following modifiers\n"
"\t to the field name, as applicable:\n\n"
"\t .hex display a number as a hex value\n"
"\t .sym display an address as a symbol\n"
"\t .sym-offset display an address as a symbol and offset\n"
"\t .execname display a common_pid as a program name\n"
"\t .syscall display a syscall id as a syscall name\n\n"
"\t .log2 display log2 value rather than raw number\n\n"
"\t The 'pause' parameter can be used to pause an existing hist\n"
"\t trigger or to start a hist trigger but not log any events\n"
"\t until told to do so. 'continue' can be used to start or\n"
"\t restart a paused hist trigger.\n\n"
"\t The 'clear' parameter will clear the contents of a running\n"
"\t hist trigger and leave its current paused/active state\n"
"\t unchanged.\n\n"
"\t The enable_hist and disable_hist triggers can be used to\n"
"\t have one event conditionally start and stop another event's\n"
"\t already-attached hist trigger. The syntax is analagous to\n"
"\t the enable_event and disable_event triggers.\n"
#endif
;
static ssize_t
......@@ -4474,7 +4631,7 @@ tracing_set_trace_write(struct file *filp, const char __user *ubuf,
if (cnt > MAX_TRACER_SIZE)
cnt = MAX_TRACER_SIZE;
if (copy_from_user(&buf, ubuf, cnt))
if (copy_from_user(buf, ubuf, cnt))
return -EFAULT;
buf[cnt] = 0;
......@@ -5264,7 +5421,7 @@ static ssize_t tracing_clock_write(struct file *filp, const char __user *ubuf,
if (cnt >= sizeof(buf))
return -EINVAL;
if (copy_from_user(&buf, ubuf, cnt))
if (copy_from_user(buf, ubuf, cnt))
return -EFAULT;
buf[cnt] = 0;
......@@ -6650,7 +6807,7 @@ static int instance_mkdir(const char *name)
if (!alloc_cpumask_var(&tr->tracing_cpumask, GFP_KERNEL))
goto out_free_tr;
tr->trace_flags = global_trace.trace_flags;
tr->trace_flags = global_trace.trace_flags & ~ZEROED_TRACE_FLAGS;
cpumask_copy(tr->tracing_cpumask, cpu_all_mask);
......@@ -6724,6 +6881,12 @@ static int instance_rmdir(const char *name)
list_del(&tr->list);
/* Disable all the flags that were enabled coming in */
for (i = 0; i < TRACE_FLAGS_MAX_SIZE; i++) {
if ((1 << i) & ZEROED_TRACE_FLAGS)
set_tracer_flag(tr, 1 << i, 0);
}
tracing_set_nop(tr);
event_trace_del_tracer(tr);
ftrace_destroy_function_files(tr);
......
kernel/trace/trace.h
View file @ 2600a46e
......@@ -177,9 +177,8 @@ struct trace_options {
};
struct trace_pid_list {
unsigned int nr_pids;
int order;
pid_t *pids;
int pid_max;
unsigned long *pids;
};
/*
......@@ -656,6 +655,7 @@ static inline void __trace_stack(struct trace_array *tr, unsigned long flags,
extern cycle_t ftrace_now(int cpu);
extern void trace_find_cmdline(int pid, char comm[]);
extern void trace_event_follow_fork(struct trace_array *tr, bool enable);
#ifdef CONFIG_DYNAMIC_FTRACE
extern unsigned long ftrace_update_tot_cnt;
......@@ -967,6 +967,7 @@ extern int trace_get_user(struct trace_parser *parser, const char __user *ubuf,
C(STOP_ON_FREE, "disable_on_free"), \
C(IRQ_INFO, "irq-info"), \
C(MARKERS, "markers"), \
C(EVENT_FORK, "event-fork"), \
FUNCTION_FLAGS \
FGRAPH_FLAGS \
STACK_FLAGS \
......@@ -1064,6 +1065,137 @@ struct trace_subsystem_dir {
int nr_events;
};
extern int call_filter_check_discard(struct trace_event_call *call, void *rec,
struct ring_buffer *buffer,
struct ring_buffer_event *event);
void trace_buffer_unlock_commit_regs(struct trace_array *tr,
struct ring_buffer *buffer,
struct ring_buffer_event *event,
unsigned long flags, int pc,
struct pt_regs *regs);
static inline void trace_buffer_unlock_commit(struct trace_array *tr,
struct ring_buffer *buffer,
struct ring_buffer_event *event,
unsigned long flags, int pc)
{
trace_buffer_unlock_commit_regs(tr, buffer, event, flags, pc, NULL);
}
DECLARE_PER_CPU(struct ring_buffer_event *, trace_buffered_event);
DECLARE_PER_CPU(int, trace_buffered_event_cnt);
void trace_buffered_event_disable(void);
void trace_buffered_event_enable(void);
static inline void
__trace_event_discard_commit(struct ring_buffer *buffer,
struct ring_buffer_event *event)
{
if (this_cpu_read(trace_buffered_event) == event) {
/* Simply release the temp buffer */
this_cpu_dec(trace_buffered_event_cnt);
return;
}
ring_buffer_discard_commit(buffer, event);
}
/*
* Helper function for event_trigger_unlock_commit{_regs}().
* If there are event triggers attached to this event that requires
* filtering against its fields, then they wil be called as the
* entry already holds the field information of the current event.
*
* It also checks if the event should be discarded or not.
* It is to be discarded if the event is soft disabled and the
* event was only recorded to process triggers, or if the event
* filter is active and this event did not match the filters.
*
* Returns true if the event is discarded, false otherwise.
*/
static inline bool
__event_trigger_test_discard(struct trace_event_file *file,
struct ring_buffer *buffer,
struct ring_buffer_event *event,
void *entry,
enum event_trigger_type *tt)
{
unsigned long eflags = file->flags;
if (eflags & EVENT_FILE_FL_TRIGGER_COND)
*tt = event_triggers_call(file, entry);
if (test_bit(EVENT_FILE_FL_SOFT_DISABLED_BIT, &file->flags) ||
(unlikely(file->flags & EVENT_FILE_FL_FILTERED) &&
!filter_match_preds(file->filter, entry))) {
__trace_event_discard_commit(buffer, event);
return true;
}
return false;
}
/**
* event_trigger_unlock_commit - handle triggers and finish event commit
* @file: The file pointer assoctiated to the event
* @buffer: The ring buffer that the event is being written to
* @event: The event meta data in the ring buffer
* @entry: The event itself
* @irq_flags: The state of the interrupts at the start of the event
* @pc: The state of the preempt count at the start of the event.
*
* This is a helper function to handle triggers that require data
* from the event itself. It also tests the event against filters and
* if the event is soft disabled and should be discarded.
*/
static inline void
event_trigger_unlock_commit(struct trace_event_file *file,
struct ring_buffer *buffer,
struct ring_buffer_event *event,
void *entry, unsigned long irq_flags, int pc)
{
enum event_trigger_type tt = ETT_NONE;
if (!__event_trigger_test_discard(file, buffer, event, entry, &tt))
trace_buffer_unlock_commit(file->tr, buffer, event, irq_flags, pc);
if (tt)
event_triggers_post_call(file, tt, entry);
}
/**
* event_trigger_unlock_commit_regs - handle triggers and finish event commit
* @file: The file pointer assoctiated to the event
* @buffer: The ring buffer that the event is being written to
* @event: The event meta data in the ring buffer
* @entry: The event itself
* @irq_flags: The state of the interrupts at the start of the event
* @pc: The state of the preempt count at the start of the event.
*
* This is a helper function to handle triggers that require data
* from the event itself. It also tests the event against filters and
* if the event is soft disabled and should be discarded.
*
* Same as event_trigger_unlock_commit() but calls
* trace_buffer_unlock_commit_regs() instead of trace_buffer_unlock_commit().
*/
static inline void
event_trigger_unlock_commit_regs(struct trace_event_file *file,
struct ring_buffer *buffer,
struct ring_buffer_event *event,
void *entry, unsigned long irq_flags, int pc,
struct pt_regs *regs)
{
enum event_trigger_type tt = ETT_NONE;
if (!__event_trigger_test_discard(file, buffer, event, entry, &tt))
trace_buffer_unlock_commit_regs(file->tr, buffer, event,
irq_flags, pc, regs);
if (tt)
event_triggers_post_call(file, tt, entry);
}
#define FILTER_PRED_INVALID ((unsigned short)-1)
#define FILTER_PRED_IS_RIGHT (1 << 15)
#define FILTER_PRED_FOLD (1 << 15)
......@@ -1161,6 +1293,15 @@ extern struct mutex event_mutex;
extern struct list_head ftrace_events;
extern const struct file_operations event_trigger_fops;
extern const struct file_operations event_hist_fops;
#ifdef CONFIG_HIST_TRIGGERS
extern int register_trigger_hist_cmd(void);
extern int register_trigger_hist_enable_disable_cmds(void);
#else
static inline int register_trigger_hist_cmd(void) { return 0; }
static inline int register_trigger_hist_enable_disable_cmds(void) { return 0; }
#endif
extern int register_trigger_cmds(void);
extern void clear_event_triggers(struct trace_array *tr);
......@@ -1174,9 +1315,41 @@ struct event_trigger_data {
char *filter_str;
void *private_data;
bool paused;
bool paused_tmp;
struct list_head list;
char *name;
struct list_head named_list;
struct event_trigger_data *named_data;
};
/* Avoid typos */
#define ENABLE_EVENT_STR "enable_event"
#define DISABLE_EVENT_STR "disable_event"
#define ENABLE_HIST_STR "enable_hist"
#define DISABLE_HIST_STR "disable_hist"
struct enable_trigger_data {
struct trace_event_file *file;
bool enable;
bool hist;
};
extern int event_enable_trigger_print(struct seq_file *m,
struct event_trigger_ops *ops,
struct event_trigger_data *data);
extern void event_enable_trigger_free(struct event_trigger_ops *ops,
struct event_trigger_data *data);
extern int event_enable_trigger_func(struct event_command *cmd_ops,
struct trace_event_file *file,
char *glob, char *cmd, char *param);
extern int event_enable_register_trigger(char *glob,
struct event_trigger_ops *ops,
struct event_trigger_data *data,
struct trace_event_file *file);
extern void event_enable_unregister_trigger(char *glob,
struct event_trigger_ops *ops,
struct event_trigger_data *test,
struct trace_event_file *file);
extern void trigger_data_free(struct event_trigger_data *data);
extern int event_trigger_init(struct event_trigger_ops *ops,
struct event_trigger_data *data);
......@@ -1189,7 +1362,18 @@ extern void unregister_trigger(char *glob, struct event_trigger_ops *ops,
extern int set_trigger_filter(char *filter_str,
struct event_trigger_data *trigger_data,
struct trace_event_file *file);
extern struct event_trigger_data *find_named_trigger(const char *name);
extern bool is_named_trigger(struct event_trigger_data *test);
extern int save_named_trigger(const char *name,
struct event_trigger_data *data);
extern void del_named_trigger(struct event_trigger_data *data);
extern void pause_named_trigger(struct event_trigger_data *data);
extern void unpause_named_trigger(struct event_trigger_data *data);
extern void set_named_trigger_data(struct event_trigger_data *data,
struct event_trigger_data *named_data);
extern int register_event_command(struct event_command *cmd);
extern int unregister_event_command(struct event_command *cmd);
extern int register_trigger_hist_enable_disable_cmds(void);
/**
* struct event_trigger_ops - callbacks for trace event triggers
......
kernel/trace/trace_events.c
View file @ 2600a46e
......@@ -15,7 +15,7 @@
#include <linux/kthread.h>
#include <linux/tracefs.h>
#include <linux/uaccess.h>
#include <linux/bsearch.h>
#include <linux/vmalloc.h>
#include <linux/module.h>
#include <linux/ctype.h>
#include <linux/sort.h>
......@@ -381,6 +381,7 @@ static int __ftrace_event_enable_disable(struct trace_event_file *file,
{
struct trace_event_call *call = file->event_call;
struct trace_array *tr = file->tr;
unsigned long file_flags = file->flags;
int ret = 0;
int disable;
......@@ -463,6 +464,15 @@ static int __ftrace_event_enable_disable(struct trace_event_file *file,
break;
}
/* Enable or disable use of trace_buffered_event */
if ((file_flags & EVENT_FILE_FL_SOFT_DISABLED) !=
(file->flags & EVENT_FILE_FL_SOFT_DISABLED)) {
if (file->flags & EVENT_FILE_FL_SOFT_DISABLED)
trace_buffered_event_enable();
else
trace_buffered_event_disable();
}
return ret;
}
......@@ -489,24 +499,26 @@ static void ftrace_clear_events(struct trace_array *tr)
mutex_unlock(&event_mutex);
}
static int cmp_pid(const void *key, const void *elt)
/* Shouldn't this be in a header? */
extern int pid_max;
/* Returns true if found in filter */
static bool
find_filtered_pid(struct trace_pid_list *filtered_pids, pid_t search_pid)
{
const pid_t *search_pid = key;
const pid_t *pid = elt;
/*
* If pid_max changed after filtered_pids was created, we
* by default ignore all pids greater than the previous pid_max.
*/
if (search_pid >= filtered_pids->pid_max)
return false;
if (*search_pid == *pid)
return 0;
if (*search_pid < *pid)
return -1;
return 1;
return test_bit(search_pid, filtered_pids->pids);
}
static bool
check_ignore_pid(struct trace_pid_list *filtered_pids, struct task_struct *task)
ignore_this_task(struct trace_pid_list *filtered_pids, struct task_struct *task)
{
pid_t search_pid;
pid_t *pid;
/*
* Return false, because if filtered_pids does not exist,
* all pids are good to trace.
......@@ -514,15 +526,68 @@ check_ignore_pid(struct trace_pid_list *filtered_pids, struct task_struct *task)
if (!filtered_pids)
return false;
search_pid = task->pid;
return !find_filtered_pid(filtered_pids, task->pid);
}
static void filter_add_remove_task(struct trace_pid_list *pid_list,
struct task_struct *self,
struct task_struct *task)
{
if (!pid_list)
return;
/* For forks, we only add if the forking task is listed */
if (self) {
if (!find_filtered_pid(pid_list, self->pid))
return;
}
pid = bsearch(&search_pid, filtered_pids->pids,
filtered_pids->nr_pids, sizeof(pid_t),
cmp_pid);
if (!pid)
return true;
/* Sorry, but we don't support pid_max changing after setting */
if (task->pid >= pid_list->pid_max)
return;
return false;
/* "self" is set for forks, and NULL for exits */
if (self)
set_bit(task->pid, pid_list->pids);
else
clear_bit(task->pid, pid_list->pids);
}
static void
event_filter_pid_sched_process_exit(void *data, struct task_struct *task)
{
struct trace_pid_list *pid_list;
struct trace_array *tr = data;
pid_list = rcu_dereference_sched(tr->filtered_pids);
filter_add_remove_task(pid_list, NULL, task);
}
static void
event_filter_pid_sched_process_fork(void *data,
struct task_struct *self,
struct task_struct *task)
{
struct trace_pid_list *pid_list;
struct trace_array *tr = data;
pid_list = rcu_dereference_sched(tr->filtered_pids);
filter_add_remove_task(pid_list, self, task);
}
void trace_event_follow_fork(struct trace_array *tr, bool enable)
{
if (enable) {
register_trace_prio_sched_process_fork(event_filter_pid_sched_process_fork,
tr, INT_MIN);
register_trace_prio_sched_process_exit(event_filter_pid_sched_process_exit,
tr, INT_MAX);
} else {
unregister_trace_sched_process_fork(event_filter_pid_sched_process_fork,
tr);
unregister_trace_sched_process_exit(event_filter_pid_sched_process_exit,
tr);
}
}
static void
......@@ -535,8 +600,8 @@ event_filter_pid_sched_switch_probe_pre(void *data, bool preempt,
pid_list = rcu_dereference_sched(tr->filtered_pids);
this_cpu_write(tr->trace_buffer.data->ignore_pid,
check_ignore_pid(pid_list, prev) &&
check_ignore_pid(pid_list, next));
ignore_this_task(pid_list, prev) &&
ignore_this_task(pid_list, next));
}
static void
......@@ -549,7 +614,7 @@ event_filter_pid_sched_switch_probe_post(void *data, bool preempt,
pid_list = rcu_dereference_sched(tr->filtered_pids);
this_cpu_write(tr->trace_buffer.data->ignore_pid,
check_ignore_pid(pid_list, next));
ignore_this_task(pid_list, next));
}
static void
......@@ -565,7 +630,7 @@ event_filter_pid_sched_wakeup_probe_pre(void *data, struct task_struct *task)
pid_list = rcu_dereference_sched(tr->filtered_pids);
this_cpu_write(tr->trace_buffer.data->ignore_pid,
check_ignore_pid(pid_list, task));
ignore_this_task(pid_list, task));
}
static void
......@@ -582,7 +647,7 @@ event_filter_pid_sched_wakeup_probe_post(void *data, struct task_struct *task)
/* Set tracing if current is enabled */
this_cpu_write(tr->trace_buffer.data->ignore_pid,
check_ignore_pid(pid_list, current));
ignore_this_task(pid_list, current));
}
static void __ftrace_clear_event_pids(struct trace_array *tr)
......@@ -620,7 +685,7 @@ static void __ftrace_clear_event_pids(struct trace_array *tr)
/* Wait till all users are no longer using pid filtering */
synchronize_sched();
free_pages((unsigned long)pid_list->pids, pid_list->order);
vfree(pid_list->pids);
kfree(pid_list);
}
......@@ -964,11 +1029,32 @@ static void t_stop(struct seq_file *m, void *p)
mutex_unlock(&event_mutex);
}
static void *
p_next(struct seq_file *m, void *v, loff_t *pos)
{
struct trace_array *tr = m->private;
struct trace_pid_list *pid_list = rcu_dereference_sched(tr->filtered_pids);
unsigned long pid = (unsigned long)v;
(*pos)++;
/* pid already is +1 of the actual prevous bit */
pid = find_next_bit(pid_list->pids, pid_list->pid_max, pid);
/* Return pid + 1 to allow zero to be represented */
if (pid < pid_list->pid_max)
return (void *)(pid + 1);
return NULL;
}
static void *p_start(struct seq_file *m, loff_t *pos)
__acquires(RCU)
{
struct trace_pid_list *pid_list;
struct trace_array *tr = m->private;
unsigned long pid;
loff_t l = 0;
/*
* Grab the mutex, to keep calls to p_next() having the same
......@@ -981,10 +1067,18 @@ static void *p_start(struct seq_file *m, loff_t *pos)
pid_list = rcu_dereference_sched(tr->filtered_pids);
if (!pid_list || *pos >= pid_list->nr_pids)
if (!pid_list)
return NULL;
pid = find_first_bit(pid_list->pids, pid_list->pid_max);
if (pid >= pid_list->pid_max)
return NULL;
return (void *)&pid_list->pids[*pos];
/* Return pid + 1 so that zero can be the exit value */
for (pid++; pid && l < *pos;
pid = (unsigned long)p_next(m, (void *)pid, &l))
;
return (void *)pid;
}
static void p_stop(struct seq_file *m, void *p)
......@@ -994,25 +1088,11 @@ static void p_stop(struct seq_file *m, void *p)
mutex_unlock(&event_mutex);
}
static void *
p_next(struct seq_file *m, void *v, loff_t *pos)
{
struct trace_array *tr = m->private;
struct trace_pid_list *pid_list = rcu_dereference_sched(tr->filtered_pids);
(*pos)++;
if (*pos >= pid_list->nr_pids)
return NULL;
return (void *)&pid_list->pids[*pos];
}
static int p_show(struct seq_file *m, void *v)
{
pid_t *pid = v;
unsigned long pid = (unsigned long)v - 1;
seq_printf(m, "%d\n", *pid);
seq_printf(m, "%lu\n", pid);
return 0;
}
......@@ -1561,11 +1641,6 @@ show_header(struct file *filp, char __user *ubuf, size_t cnt, loff_t *ppos)
return r;
}
static int max_pids(struct trace_pid_list *pid_list)
{
return (PAGE_SIZE << pid_list->order) / sizeof(pid_t);
}
static void ignore_task_cpu(void *data)
{
struct trace_array *tr = data;
......@@ -1579,7 +1654,7 @@ static void ignore_task_cpu(void *data)
mutex_is_locked(&event_mutex));
this_cpu_write(tr->trace_buffer.data->ignore_pid,
check_ignore_pid(pid_list, current));
ignore_this_task(pid_list, current));
}
static ssize_t
......@@ -1589,7 +1664,7 @@ ftrace_event_pid_write(struct file *filp, const char __user *ubuf,
struct seq_file *m = filp->private_data;
struct trace_array *tr = m->private;
struct trace_pid_list *filtered_pids = NULL;
struct trace_pid_list *pid_list = NULL;
struct trace_pid_list *pid_list;
struct trace_event_file *file;
struct trace_parser parser;
unsigned long val;
......@@ -1597,7 +1672,7 @@ ftrace_event_pid_write(struct file *filp, const char __user *ubuf,
ssize_t read = 0;
ssize_t ret = 0;
pid_t pid;
int i;
int nr_pids = 0;
if (!cnt)
return 0;
......@@ -1610,10 +1685,43 @@ ftrace_event_pid_write(struct file *filp, const char __user *ubuf,
return -ENOMEM;
mutex_lock(&event_mutex);
filtered_pids = rcu_dereference_protected(tr->filtered_pids,
lockdep_is_held(&event_mutex));
/*
* Load as many pids into the array before doing a
* swap from the tr->filtered_pids to the new list.
* Always recreate a new array. The write is an all or nothing
* operation. Always create a new array when adding new pids by
* the user. If the operation fails, then the current list is
* not modified.
*/
pid_list = kmalloc(sizeof(*pid_list), GFP_KERNEL);
if (!pid_list) {
read = -ENOMEM;
goto out;
}
pid_list->pid_max = READ_ONCE(pid_max);
/* Only truncating will shrink pid_max */
if (filtered_pids && filtered_pids->pid_max > pid_list->pid_max)
pid_list->pid_max = filtered_pids->pid_max;
pid_list->pids = vzalloc((pid_list->pid_max + 7) >> 3);
if (!pid_list->pids) {
kfree(pid_list);
read = -ENOMEM;
goto out;
}
if (filtered_pids) {
/* copy the current bits to the new max */
pid = find_first_bit(filtered_pids->pids,
filtered_pids->pid_max);
while (pid < filtered_pids->pid_max) {
set_bit(pid, pid_list->pids);
pid = find_next_bit(filtered_pids->pids,
filtered_pids->pid_max,
pid + 1);
nr_pids++;
}
}
while (cnt > 0) {
this_pos = 0;
......@@ -1631,92 +1739,35 @@ ftrace_event_pid_write(struct file *filp, const char __user *ubuf,
ret = -EINVAL;
if (kstrtoul(parser.buffer, 0, &val))
break;
if (val > INT_MAX)
if (val >= pid_list->pid_max)
break;
pid = (pid_t)val;
ret = -ENOMEM;
if (!pid_list) {
pid_list = kmalloc(sizeof(*pid_list), GFP_KERNEL);
if (!pid_list)
break;
set_bit(pid, pid_list->pids);
nr_pids++;
filtered_pids = rcu_dereference_protected(tr->filtered_pids,
lockdep_is_held(&event_mutex));
if (filtered_pids)
pid_list->order = filtered_pids->order;
else
pid_list->order = 0;
pid_list->pids = (void *)__get_free_pages(GFP_KERNEL,
pid_list->order);
if (!pid_list->pids)
break;
if (filtered_pids) {
pid_list->nr_pids = filtered_pids->nr_pids;
memcpy(pid_list->pids, filtered_pids->pids,
pid_list->nr_pids * sizeof(pid_t));
} else
pid_list->nr_pids = 0;
}
if (pid_list->nr_pids >= max_pids(pid_list)) {
pid_t *pid_page;
pid_page = (void *)__get_free_pages(GFP_KERNEL,
pid_list->order + 1);
if (!pid_page)
break;
memcpy(pid_page, pid_list->pids,
pid_list->nr_pids * sizeof(pid_t));
free_pages((unsigned long)pid_list->pids, pid_list->order);
pid_list->order++;
pid_list->pids = pid_page;
}
pid_list->pids[pid_list->nr_pids++] = pid;
trace_parser_clear(&parser);
ret = 0;
}
trace_parser_put(&parser);
if (ret < 0) {
if (pid_list)
free_pages((unsigned long)pid_list->pids, pid_list->order);
vfree(pid_list->pids);
kfree(pid_list);
mutex_unlock(&event_mutex);
return ret;
}
if (!pid_list) {
mutex_unlock(&event_mutex);
return ret;
read = ret;
goto out;
}
sort(pid_list->pids, pid_list->nr_pids, sizeof(pid_t), cmp_pid, NULL);
/* Remove duplicates */
for (i = 1; i < pid_list->nr_pids; i++) {
int start = i;
while (i < pid_list->nr_pids &&
pid_list->pids[i - 1] == pid_list->pids[i])
i++;
if (start != i) {
if (i < pid_list->nr_pids) {
memmove(&pid_list->pids[start], &pid_list->pids[i],
(pid_list->nr_pids - i) * sizeof(pid_t));
pid_list->nr_pids -= i - start;
i = start;
} else
pid_list->nr_pids = start;
}
if (!nr_pids) {
/* Cleared the list of pids */
vfree(pid_list->pids);
kfree(pid_list);
read = ret;
if (!filtered_pids)
goto out;
pid_list = NULL;
}
rcu_assign_pointer(tr->filtered_pids, pid_list);
list_for_each_entry(file, &tr->events, list) {
......@@ -1726,7 +1777,7 @@ ftrace_event_pid_write(struct file *filp, const char __user *ubuf,
if (filtered_pids) {
synchronize_sched();
free_pages((unsigned long)filtered_pids->pids, filtered_pids->order);
vfree(filtered_pids->pids);
kfree(filtered_pids);
} else {
/*
......@@ -1763,10 +1814,12 @@ ftrace_event_pid_write(struct file *filp, const char __user *ubuf,
*/
on_each_cpu(ignore_task_cpu, tr, 1);
out:
mutex_unlock(&event_mutex);
ret = read;
*ppos += read;
if (read > 0)
*ppos += read;
return ret;
}
......@@ -2121,6 +2174,10 @@ event_create_dir(struct dentry *parent, struct trace_event_file *file)
trace_create_file("trigger", 0644, file->dir, file,
&event_trigger_fops);
#ifdef CONFIG_HIST_TRIGGERS
trace_create_file("hist", 0444, file->dir, file,
&event_hist_fops);
#endif
trace_create_file("format", 0444, file->dir, call,
&ftrace_event_format_fops);
......@@ -3368,7 +3425,7 @@ static __init void event_trace_self_tests(void)
static DEFINE_PER_CPU(atomic_t, ftrace_test_event_disable);
static struct trace_array *event_tr;
static struct trace_event_file event_trace_file __initdata;
static void __init
function_test_events_call(unsigned long ip, unsigned long parent_ip,
......@@ -3392,17 +3449,17 @@ function_test_events_call(unsigned long ip, unsigned long parent_ip,
local_save_flags(flags);
event = trace_current_buffer_lock_reserve(&buffer,
TRACE_FN, sizeof(*entry),
flags, pc);
event = trace_event_buffer_lock_reserve(&buffer, &event_trace_file,
TRACE_FN, sizeof(*entry),
flags, pc);
if (!event)
goto out;
entry = ring_buffer_event_data(event);
entry->ip = ip;
entry->parent_ip = parent_ip;
trace_buffer_unlock_commit(event_tr, buffer, event, flags, pc);
event_trigger_unlock_commit(&event_trace_file, buffer, event,
entry, flags, pc);
out:
atomic_dec(&per_cpu(ftrace_test_event_disable, cpu));
preempt_enable_notrace();
......@@ -3417,9 +3474,11 @@ static struct ftrace_ops trace_ops __initdata =
static __init void event_trace_self_test_with_function(void)
{
int ret;
event_tr = top_trace_array();
if (WARN_ON(!event_tr))
event_trace_file.tr = top_trace_array();
if (WARN_ON(!event_trace_file.tr))
return;
ret = register_ftrace_function(&trace_ops);
if (WARN_ON(ret < 0)) {
pr_info("Failed to enable function tracer for event tests\n");
......
kernel/trace/trace_events_filter.c
View file @ 2600a46e
......@@ -689,10 +689,7 @@ static void append_filter_err(struct filter_parse_state *ps,
static inline struct event_filter *event_filter(struct trace_event_file *file)
{
if (file->event_call->flags & TRACE_EVENT_FL_USE_CALL_FILTER)
return file->event_call->filter;
else
return file->filter;
return file->filter;
}
/* caller must hold event_mutex */
......@@ -826,12 +823,12 @@ static void __free_preds(struct event_filter *filter)
static void filter_disable(struct trace_event_file *file)
{
struct trace_event_call *call = file->event_call;
unsigned long old_flags = file->flags;
if (call->flags & TRACE_EVENT_FL_USE_CALL_FILTER)
call->flags &= ~TRACE_EVENT_FL_FILTERED;
else
file->flags &= ~EVENT_FILE_FL_FILTERED;
file->flags &= ~EVENT_FILE_FL_FILTERED;
if (old_flags != file->flags)
trace_buffered_event_disable();
}
static void __free_filter(struct event_filter *filter)
......@@ -883,13 +880,8 @@ static int __alloc_preds(struct event_filter *filter, int n_preds)
static inline void __remove_filter(struct trace_event_file *file)
{
struct trace_event_call *call = file->event_call;
filter_disable(file);
if (call->flags & TRACE_EVENT_FL_USE_CALL_FILTER)
remove_filter_string(call->filter);
else
remove_filter_string(file->filter);
remove_filter_string(file->filter);
}
static void filter_free_subsystem_preds(struct trace_subsystem_dir *dir,
......@@ -906,15 +898,8 @@ static void filter_free_subsystem_preds(struct trace_subsystem_dir *dir,
static inline void __free_subsystem_filter(struct trace_event_file *file)
{
struct trace_event_call *call = file->event_call;
if (call->flags & TRACE_EVENT_FL_USE_CALL_FILTER) {
__free_filter(call->filter);
call->filter = NULL;
} else {
__free_filter(file->filter);
file->filter = NULL;
}
__free_filter(file->filter);
file->filter = NULL;
}
static void filter_free_subsystem_filters(struct trace_subsystem_dir *dir,
......@@ -1718,69 +1703,43 @@ static int replace_preds(struct trace_event_call *call,
static inline void event_set_filtered_flag(struct trace_event_file *file)
{
struct trace_event_call *call = file->event_call;
unsigned long old_flags = file->flags;
if (call->flags & TRACE_EVENT_FL_USE_CALL_FILTER)
call->flags |= TRACE_EVENT_FL_FILTERED;
else
file->flags |= EVENT_FILE_FL_FILTERED;
file->flags |= EVENT_FILE_FL_FILTERED;
if (old_flags != file->flags)
trace_buffered_event_enable();
}
static inline void event_set_filter(struct trace_event_file *file,
struct event_filter *filter)
{
struct trace_event_call *call = file->event_call;
if (call->flags & TRACE_EVENT_FL_USE_CALL_FILTER)
rcu_assign_pointer(call->filter, filter);
else
rcu_assign_pointer(file->filter, filter);
rcu_assign_pointer(file->filter, filter);
}
static inline void event_clear_filter(struct trace_event_file *file)
{
struct trace_event_call *call = file->event_call;
if (call->flags & TRACE_EVENT_FL_USE_CALL_FILTER)
RCU_INIT_POINTER(call->filter, NULL);
else
RCU_INIT_POINTER(file->filter, NULL);
RCU_INIT_POINTER(file->filter, NULL);
}
static inline void
event_set_no_set_filter_flag(struct trace_event_file *file)
{
struct trace_event_call *call = file->event_call;
if (call->flags & TRACE_EVENT_FL_USE_CALL_FILTER)
call->flags |= TRACE_EVENT_FL_NO_SET_FILTER;
else
file->flags |= EVENT_FILE_FL_NO_SET_FILTER;
file->flags |= EVENT_FILE_FL_NO_SET_FILTER;
}
static inline void
event_clear_no_set_filter_flag(struct trace_event_file *file)
{
struct trace_event_call *call = file->event_call;
if (call->flags & TRACE_EVENT_FL_USE_CALL_FILTER)
call->flags &= ~TRACE_EVENT_FL_NO_SET_FILTER;
else
file->flags &= ~EVENT_FILE_FL_NO_SET_FILTER;
file->flags &= ~EVENT_FILE_FL_NO_SET_FILTER;
}
static inline bool
event_no_set_filter_flag(struct trace_event_file *file)
{
struct trace_event_call *call = file->event_call;
if (file->flags & EVENT_FILE_FL_NO_SET_FILTER)
return true;
if ((call->flags & TRACE_EVENT_FL_USE_CALL_FILTER) &&
(call->flags & TRACE_EVENT_FL_NO_SET_FILTER))
return true;
return false;
}
......
kernel/trace/trace_events_hist.c 0 → 100644
View file @ 2600a46e
/*
* trace_events_hist - trace event hist triggers
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* Copyright (C) 2015 Tom Zanussi <tom.zanussi@linux.intel.com>
*/
#include <linux/module.h>
#include <linux/kallsyms.h>
#include <linux/mutex.h>
#include <linux/slab.h>
#include <linux/stacktrace.h>
#include "tracing_map.h"
#include "trace.h"
struct hist_field;
typedef u64 (*hist_field_fn_t) (struct hist_field *field, void *event);
struct hist_field {
struct ftrace_event_field *field;
unsigned long flags;
hist_field_fn_t fn;
unsigned int size;
unsigned int offset;
};
static u64 hist_field_none(struct hist_field *field, void *event)
{
return 0;
}
static u64 hist_field_counter(struct hist_field *field, void *event)
{
return 1;
}
static u64 hist_field_string(struct hist_field *hist_field, void *event)
{
char *addr = (char *)(event + hist_field->field->offset);
return (u64)(unsigned long)addr;
}
static u64 hist_field_dynstring(struct hist_field *hist_field, void *event)
{
u32 str_item = *(u32 *)(event + hist_field->field->offset);
int str_loc = str_item & 0xffff;
char *addr = (char *)(event + str_loc);
return (u64)(unsigned long)addr;
}
static u64 hist_field_pstring(struct hist_field *hist_field, void *event)
{
char **addr = (char **)(event + hist_field->field->offset);
return (u64)(unsigned long)*addr;
}
static u64 hist_field_log2(struct hist_field *hist_field, void *event)
{
u64 val = *(u64 *)(event + hist_field->field->offset);
return (u64) ilog2(roundup_pow_of_two(val));
}
#define DEFINE_HIST_FIELD_FN(type) \
static u64 hist_field_##type(struct hist_field *hist_field, void *event)\
{ \
type *addr = (type *)(event + hist_field->field->offset); \
\
return (u64)(unsigned long)*addr; \
}
DEFINE_HIST_FIELD_FN(s64);
DEFINE_HIST_FIELD_FN(u64);
DEFINE_HIST_FIELD_FN(s32);
DEFINE_HIST_FIELD_FN(u32);
DEFINE_HIST_FIELD_FN(s16);
DEFINE_HIST_FIELD_FN(u16);
DEFINE_HIST_FIELD_FN(s8);
DEFINE_HIST_FIELD_FN(u8);
#define for_each_hist_field(i, hist_data) \
for ((i) = 0; (i) < (hist_data)->n_fields; (i)++)
#define for_each_hist_val_field(i, hist_data) \
for ((i) = 0; (i) < (hist_data)->n_vals; (i)++)
#define for_each_hist_key_field(i, hist_data) \
for ((i) = (hist_data)->n_vals; (i) < (hist_data)->n_fields; (i)++)
#define HIST_STACKTRACE_DEPTH 16
#define HIST_STACKTRACE_SIZE (HIST_STACKTRACE_DEPTH * sizeof(unsigned long))
#define HIST_STACKTRACE_SKIP 5
#define HITCOUNT_IDX 0
#define HIST_KEY_SIZE_MAX (MAX_FILTER_STR_VAL + HIST_STACKTRACE_SIZE)
enum hist_field_flags {
HIST_FIELD_FL_HITCOUNT = 1,
HIST_FIELD_FL_KEY = 2,
HIST_FIELD_FL_STRING = 4,
HIST_FIELD_FL_HEX = 8,
HIST_FIELD_FL_SYM = 16,
HIST_FIELD_FL_SYM_OFFSET = 32,
HIST_FIELD_FL_EXECNAME = 64,
HIST_FIELD_FL_SYSCALL = 128,
HIST_FIELD_FL_STACKTRACE = 256,
HIST_FIELD_FL_LOG2 = 512,
};
struct hist_trigger_attrs {
char *keys_str;
char *vals_str;
char *sort_key_str;
char *name;
bool pause;
bool cont;
bool clear;
unsigned int map_bits;
};
struct hist_trigger_data {
struct hist_field *fields[TRACING_MAP_FIELDS_MAX];
unsigned int n_vals;
unsigned int n_keys;
unsigned int n_fields;
unsigned int key_size;
struct tracing_map_sort_key sort_keys[TRACING_MAP_SORT_KEYS_MAX];
unsigned int n_sort_keys;
struct trace_event_file *event_file;
struct hist_trigger_attrs *attrs;
struct tracing_map *map;
};
static hist_field_fn_t select_value_fn(int field_size, int field_is_signed)
{
hist_field_fn_t fn = NULL;
switch (field_size) {
case 8:
if (field_is_signed)
fn = hist_field_s64;
else
fn = hist_field_u64;
break;
case 4:
if (field_is_signed)
fn = hist_field_s32;
else
fn = hist_field_u32;
break;
case 2:
if (field_is_signed)
fn = hist_field_s16;
else
fn = hist_field_u16;
break;
case 1:
if (field_is_signed)
fn = hist_field_s8;
else
fn = hist_field_u8;
break;
}
return fn;
}
static int parse_map_size(char *str)
{
unsigned long size, map_bits;
int ret;
strsep(&str, "=");
if (!str) {
ret = -EINVAL;
goto out;
}
ret = kstrtoul(str, 0, &size);
if (ret)
goto out;
map_bits = ilog2(roundup_pow_of_two(size));
if (map_bits < TRACING_MAP_BITS_MIN ||
map_bits > TRACING_MAP_BITS_MAX)
ret = -EINVAL;
else
ret = map_bits;
out:
return ret;
}
static void destroy_hist_trigger_attrs(struct hist_trigger_attrs *attrs)
{
if (!attrs)
return;
kfree(attrs->name);
kfree(attrs->sort_key_str);
kfree(attrs->keys_str);
kfree(attrs->vals_str);
kfree(attrs);
}
static struct hist_trigger_attrs *parse_hist_trigger_attrs(char *trigger_str)
{
struct hist_trigger_attrs *attrs;
int ret = 0;
attrs = kzalloc(sizeof(*attrs), GFP_KERNEL);
if (!attrs)
return ERR_PTR(-ENOMEM);
while (trigger_str) {
char *str = strsep(&trigger_str, ":");
if ((strncmp(str, "key=", strlen("key=")) == 0) ||
(strncmp(str, "keys=", strlen("keys=")) == 0))
attrs->keys_str = kstrdup(str, GFP_KERNEL);
else if ((strncmp(str, "val=", strlen("val=")) == 0) ||
(strncmp(str, "vals=", strlen("vals=")) == 0) ||
(strncmp(str, "values=", strlen("values=")) == 0))
attrs->vals_str = kstrdup(str, GFP_KERNEL);
else if (strncmp(str, "sort=", strlen("sort=")) == 0)
attrs->sort_key_str = kstrdup(str, GFP_KERNEL);
else if (strncmp(str, "name=", strlen("name=")) == 0)
attrs->name = kstrdup(str, GFP_KERNEL);
else if (strcmp(str, "pause") == 0)
attrs->pause = true;
else if ((strcmp(str, "cont") == 0) ||
(strcmp(str, "continue") == 0))
attrs->cont = true;
else if (strcmp(str, "clear") == 0)
attrs->clear = true;
else if (strncmp(str, "size=", strlen("size=")) == 0) {
int map_bits = parse_map_size(str);
if (map_bits < 0) {
ret = map_bits;
goto free;
}
attrs->map_bits = map_bits;
} else {
ret = -EINVAL;
goto free;
}
}
if (!attrs->keys_str) {
ret = -EINVAL;
goto free;
}
return attrs;
free:
destroy_hist_trigger_attrs(attrs);
return ERR_PTR(ret);
}
static inline void save_comm(char *comm, struct task_struct *task)
{
if (!task->pid) {
strcpy(comm, "<idle>");
return;
}
if (WARN_ON_ONCE(task->pid < 0)) {
strcpy(comm, "<XXX>");
return;
}
memcpy(comm, task->comm, TASK_COMM_LEN);
}
static void hist_trigger_elt_comm_free(struct tracing_map_elt *elt)
{
kfree((char *)elt->private_data);
}
static int hist_trigger_elt_comm_alloc(struct tracing_map_elt *elt)
{
struct hist_trigger_data *hist_data = elt->map->private_data;
struct hist_field *key_field;
unsigned int i;
for_each_hist_key_field(i, hist_data) {
key_field = hist_data->fields[i];
if (key_field->flags & HIST_FIELD_FL_EXECNAME) {
unsigned int size = TASK_COMM_LEN + 1;
elt->private_data = kzalloc(size, GFP_KERNEL);
if (!elt->private_data)
return -ENOMEM;
break;
}
}
return 0;
}
static void hist_trigger_elt_comm_copy(struct tracing_map_elt *to,
struct tracing_map_elt *from)
{
char *comm_from = from->private_data;
char *comm_to = to->private_data;
if (comm_from)
memcpy(comm_to, comm_from, TASK_COMM_LEN + 1);
}
static void hist_trigger_elt_comm_init(struct tracing_map_elt *elt)
{
char *comm = elt->private_data;
if (comm)
save_comm(comm, current);
}
static const struct tracing_map_ops hist_trigger_elt_comm_ops = {
.elt_alloc = hist_trigger_elt_comm_alloc,
.elt_copy = hist_trigger_elt_comm_copy,
.elt_free = hist_trigger_elt_comm_free,
.elt_init = hist_trigger_elt_comm_init,
};
static void destroy_hist_field(struct hist_field *hist_field)
{
kfree(hist_field);
}
static struct hist_field *create_hist_field(struct ftrace_event_field *field,
unsigned long flags)
{
struct hist_field *hist_field;
if (field && is_function_field(field))
return NULL;
hist_field = kzalloc(sizeof(struct hist_field), GFP_KERNEL);
if (!hist_field)
return NULL;
if (flags & HIST_FIELD_FL_HITCOUNT) {
hist_field->fn = hist_field_counter;
goto out;
}
if (flags & HIST_FIELD_FL_STACKTRACE) {
hist_field->fn = hist_field_none;
goto out;
}
if (flags & HIST_FIELD_FL_LOG2) {
hist_field->fn = hist_field_log2;
goto out;
}
if (WARN_ON_ONCE(!field))
goto out;
if (is_string_field(field)) {
flags |= HIST_FIELD_FL_STRING;
if (field->filter_type == FILTER_STATIC_STRING)
hist_field->fn = hist_field_string;
else if (field->filter_type == FILTER_DYN_STRING)
hist_field->fn = hist_field_dynstring;
else
hist_field->fn = hist_field_pstring;
} else {
hist_field->fn = select_value_fn(field->size,
field->is_signed);
if (!hist_field->fn) {
destroy_hist_field(hist_field);
return NULL;
}
}
out:
hist_field->field = field;
hist_field->flags = flags;
return hist_field;
}
static void destroy_hist_fields(struct hist_trigger_data *hist_data)
{
unsigned int i;
for (i = 0; i < TRACING_MAP_FIELDS_MAX; i++) {
if (hist_data->fields[i]) {
destroy_hist_field(hist_data->fields[i]);
hist_data->fields[i] = NULL;
}
}
}
static int create_hitcount_val(struct hist_trigger_data *hist_data)
{
hist_data->fields[HITCOUNT_IDX] =
create_hist_field(NULL, HIST_FIELD_FL_HITCOUNT);
if (!hist_data->fields[HITCOUNT_IDX])
return -ENOMEM;
hist_data->n_vals++;
if (WARN_ON(hist_data->n_vals > TRACING_MAP_VALS_MAX))
return -EINVAL;
return 0;
}
static int create_val_field(struct hist_trigger_data *hist_data,
unsigned int val_idx,
struct trace_event_file *file,
char *field_str)
{
struct ftrace_event_field *field = NULL;
unsigned long flags = 0;
char *field_name;
int ret = 0;
if (WARN_ON(val_idx >= TRACING_MAP_VALS_MAX))
return -EINVAL;
field_name = strsep(&field_str, ".");
if (field_str) {
if (strcmp(field_str, "hex") == 0)
flags |= HIST_FIELD_FL_HEX;
else {
ret = -EINVAL;
goto out;
}
}
field = trace_find_event_field(file->event_call, field_name);
if (!field) {
ret = -EINVAL;
goto out;
}
hist_data->fields[val_idx] = create_hist_field(field, flags);
if (!hist_data->fields[val_idx]) {
ret = -ENOMEM;
goto out;
}
++hist_data->n_vals;
if (WARN_ON(hist_data->n_vals > TRACING_MAP_VALS_MAX))
ret = -EINVAL;
out:
return ret;
}
static int create_val_fields(struct hist_trigger_data *hist_data,
struct trace_event_file *file)
{
char *fields_str, *field_str;
unsigned int i, j;
int ret;
ret = create_hitcount_val(hist_data);
if (ret)
goto out;
fields_str = hist_data->attrs->vals_str;
if (!fields_str)
goto out;
strsep(&fields_str, "=");
if (!fields_str)
goto out;
for (i = 0, j = 1; i < TRACING_MAP_VALS_MAX &&
j < TRACING_MAP_VALS_MAX; i++) {
field_str = strsep(&fields_str, ",");
if (!field_str)
break;
if (strcmp(field_str, "hitcount") == 0)
continue;
ret = create_val_field(hist_data, j++, file, field_str);
if (ret)
goto out;
}
if (fields_str && (strcmp(fields_str, "hitcount") != 0))
ret = -EINVAL;
out:
return ret;
}
static int create_key_field(struct hist_trigger_data *hist_data,
unsigned int key_idx,
unsigned int key_offset,
struct trace_event_file *file,
char *field_str)
{
struct ftrace_event_field *field = NULL;
unsigned long flags = 0;
unsigned int key_size;
int ret = 0;
if (WARN_ON(key_idx >= TRACING_MAP_FIELDS_MAX))
return -EINVAL;
flags |= HIST_FIELD_FL_KEY;
if (strcmp(field_str, "stacktrace") == 0) {
flags |= HIST_FIELD_FL_STACKTRACE;
key_size = sizeof(unsigned long) * HIST_STACKTRACE_DEPTH;
} else {
char *field_name = strsep(&field_str, ".");
if (field_str) {
if (strcmp(field_str, "hex") == 0)
flags |= HIST_FIELD_FL_HEX;
else if (strcmp(field_str, "sym") == 0)
flags |= HIST_FIELD_FL_SYM;
else if (strcmp(field_str, "sym-offset") == 0)
flags |= HIST_FIELD_FL_SYM_OFFSET;
else if ((strcmp(field_str, "execname") == 0) &&
(strcmp(field_name, "common_pid") == 0))
flags |= HIST_FIELD_FL_EXECNAME;
else if (strcmp(field_str, "syscall") == 0)
flags |= HIST_FIELD_FL_SYSCALL;
else if (strcmp(field_str, "log2") == 0)
flags |= HIST_FIELD_FL_LOG2;
else {
ret = -EINVAL;
goto out;
}
}
field = trace_find_event_field(file->event_call, field_name);
if (!field) {
ret = -EINVAL;
goto out;
}
if (is_string_field(field))
key_size = MAX_FILTER_STR_VAL;
else
key_size = field->size;
}
hist_data->fields[key_idx] = create_hist_field(field, flags);
if (!hist_data->fields[key_idx]) {
ret = -ENOMEM;
goto out;
}
key_size = ALIGN(key_size, sizeof(u64));
hist_data->fields[key_idx]->size = key_size;
hist_data->fields[key_idx]->offset = key_offset;
hist_data->key_size += key_size;
if (hist_data->key_size > HIST_KEY_SIZE_MAX) {
ret = -EINVAL;
goto out;
}
hist_data->n_keys++;
if (WARN_ON(hist_data->n_keys > TRACING_MAP_KEYS_MAX))
return -EINVAL;
ret = key_size;
out:
return ret;
}
static int create_key_fields(struct hist_trigger_data *hist_data,
struct trace_event_file *file)
{
unsigned int i, key_offset = 0, n_vals = hist_data->n_vals;
char *fields_str, *field_str;
int ret = -EINVAL;
fields_str = hist_data->attrs->keys_str;
if (!fields_str)
goto out;
strsep(&fields_str, "=");
if (!fields_str)
goto out;
for (i = n_vals; i < n_vals + TRACING_MAP_KEYS_MAX; i++) {
field_str = strsep(&fields_str, ",");
if (!field_str)
break;
ret = create_key_field(hist_data, i, key_offset,
file, field_str);
if (ret < 0)
goto out;
key_offset += ret;
}
if (fields_str) {
ret = -EINVAL;
goto out;
}
ret = 0;
out:
return ret;
}
static int create_hist_fields(struct hist_trigger_data *hist_data,
struct trace_event_file *file)
{
int ret;
ret = create_val_fields(hist_data, file);
if (ret)
goto out;
ret = create_key_fields(hist_data, file);
if (ret)
goto out;
hist_data->n_fields = hist_data->n_vals + hist_data->n_keys;
out:
return ret;
}
static int is_descending(const char *str)
{
if (!str)
return 0;
if (strcmp(str, "descending") == 0)
return 1;
if (strcmp(str, "ascending") == 0)
return 0;
return -EINVAL;
}
static int create_sort_keys(struct hist_trigger_data *hist_data)
{
char *fields_str = hist_data->attrs->sort_key_str;
struct ftrace_event_field *field = NULL;
struct tracing_map_sort_key *sort_key;
int descending, ret = 0;
unsigned int i, j;
hist_data->n_sort_keys = 1; /* we always have at least one, hitcount */
if (!fields_str)
goto out;
strsep(&fields_str, "=");
if (!fields_str) {
ret = -EINVAL;
goto out;
}
for (i = 0; i < TRACING_MAP_SORT_KEYS_MAX; i++) {
char *field_str, *field_name;
sort_key = &hist_data->sort_keys[i];
field_str = strsep(&fields_str, ",");
if (!field_str) {
if (i == 0)
ret = -EINVAL;
break;
}
if ((i == TRACING_MAP_SORT_KEYS_MAX - 1) && fields_str) {
ret = -EINVAL;
break;
}
field_name = strsep(&field_str, ".");
if (!field_name) {
ret = -EINVAL;
break;
}
if (strcmp(field_name, "hitcount") == 0) {
descending = is_descending(field_str);
if (descending < 0) {
ret = descending;
break;
}
sort_key->descending = descending;
continue;
}
for (j = 1; j < hist_data->n_fields; j++) {
field = hist_data->fields[j]->field;
if (field && (strcmp(field_name, field->name) == 0)) {
sort_key->field_idx = j;
descending = is_descending(field_str);
if (descending < 0) {
ret = descending;
goto out;
}
sort_key->descending = descending;
break;
}
}
if (j == hist_data->n_fields) {
ret = -EINVAL;
break;
}
}
hist_data->n_sort_keys = i;
out:
return ret;
}
static void destroy_hist_data(struct hist_trigger_data *hist_data)
{
destroy_hist_trigger_attrs(hist_data->attrs);
destroy_hist_fields(hist_data);
tracing_map_destroy(hist_data->map);
kfree(hist_data);
}
static int create_tracing_map_fields(struct hist_trigger_data *hist_data)
{
struct tracing_map *map = hist_data->map;
struct ftrace_event_field *field;
struct hist_field *hist_field;
int i, idx;
for_each_hist_field(i, hist_data) {
hist_field = hist_data->fields[i];
if (hist_field->flags & HIST_FIELD_FL_KEY) {
tracing_map_cmp_fn_t cmp_fn;
field = hist_field->field;
if (hist_field->flags & HIST_FIELD_FL_STACKTRACE)
cmp_fn = tracing_map_cmp_none;
else if (is_string_field(field))
cmp_fn = tracing_map_cmp_string;
else
cmp_fn = tracing_map_cmp_num(field->size,
field->is_signed);
idx = tracing_map_add_key_field(map,
hist_field->offset,
cmp_fn);
} else
idx = tracing_map_add_sum_field(map);
if (idx < 0)
return idx;
}
return 0;
}
static bool need_tracing_map_ops(struct hist_trigger_data *hist_data)
{
struct hist_field *key_field;
unsigned int i;
for_each_hist_key_field(i, hist_data) {
key_field = hist_data->fields[i];
if (key_field->flags & HIST_FIELD_FL_EXECNAME)
return true;
}
return false;
}
static struct hist_trigger_data *
create_hist_data(unsigned int map_bits,
struct hist_trigger_attrs *attrs,
struct trace_event_file *file)
{
const struct tracing_map_ops *map_ops = NULL;
struct hist_trigger_data *hist_data;
int ret = 0;
hist_data = kzalloc(sizeof(*hist_data), GFP_KERNEL);
if (!hist_data)
return ERR_PTR(-ENOMEM);
hist_data->attrs = attrs;
ret = create_hist_fields(hist_data, file);
if (ret)
goto free;
ret = create_sort_keys(hist_data);
if (ret)
goto free;
if (need_tracing_map_ops(hist_data))
map_ops = &hist_trigger_elt_comm_ops;
hist_data->map = tracing_map_create(map_bits, hist_data->key_size,
map_ops, hist_data);
if (IS_ERR(hist_data->map)) {
ret = PTR_ERR(hist_data->map);
hist_data->map = NULL;
goto free;
}
ret = create_tracing_map_fields(hist_data);
if (ret)
goto free;
ret = tracing_map_init(hist_data->map);
if (ret)
goto free;
hist_data->event_file = file;
out:
return hist_data;
free:
hist_data->attrs = NULL;
destroy_hist_data(hist_data);
hist_data = ERR_PTR(ret);
goto out;
}
static void hist_trigger_elt_update(struct hist_trigger_data *hist_data,
struct tracing_map_elt *elt,
void *rec)
{
struct hist_field *hist_field;
unsigned int i;
u64 hist_val;
for_each_hist_val_field(i, hist_data) {
hist_field = hist_data->fields[i];
hist_val = hist_field->fn(hist_field, rec);
tracing_map_update_sum(elt, i, hist_val);
}
}
static inline void add_to_key(char *compound_key, void *key,
struct hist_field *key_field, void *rec)
{
size_t size = key_field->size;
if (key_field->flags & HIST_FIELD_FL_STRING) {
struct ftrace_event_field *field;
field = key_field->field;
if (field->filter_type == FILTER_DYN_STRING)
size = *(u32 *)(rec + field->offset) >> 16;
else if (field->filter_type == FILTER_PTR_STRING)
size = strlen(key);
else if (field->filter_type == FILTER_STATIC_STRING)
size = field->size;
/* ensure NULL-termination */
if (size > key_field->size - 1)
size = key_field->size - 1;
}
memcpy(compound_key + key_field->offset, key, size);
}
static void event_hist_trigger(struct event_trigger_data *data, void *rec)
{
struct hist_trigger_data *hist_data = data->private_data;
bool use_compound_key = (hist_data->n_keys > 1);
unsigned long entries[HIST_STACKTRACE_DEPTH];
char compound_key[HIST_KEY_SIZE_MAX];
struct stack_trace stacktrace;
struct hist_field *key_field;
struct tracing_map_elt *elt;
u64 field_contents;
void *key = NULL;
unsigned int i;
memset(compound_key, 0, hist_data->key_size);
for_each_hist_key_field(i, hist_data) {
key_field = hist_data->fields[i];
if (key_field->flags & HIST_FIELD_FL_STACKTRACE) {
stacktrace.max_entries = HIST_STACKTRACE_DEPTH;
stacktrace.entries = entries;
stacktrace.nr_entries = 0;
stacktrace.skip = HIST_STACKTRACE_SKIP;
memset(stacktrace.entries, 0, HIST_STACKTRACE_SIZE);
save_stack_trace(&stacktrace);
key = entries;
} else {
field_contents = key_field->fn(key_field, rec);
if (key_field->flags & HIST_FIELD_FL_STRING) {
key = (void *)(unsigned long)field_contents;
use_compound_key = true;
} else
key = (void *)&field_contents;
}
if (use_compound_key)
add_to_key(compound_key, key, key_field, rec);
}
if (use_compound_key)
key = compound_key;
elt = tracing_map_insert(hist_data->map, key);
if (elt)
hist_trigger_elt_update(hist_data, elt, rec);
}
static void hist_trigger_stacktrace_print(struct seq_file *m,
unsigned long *stacktrace_entries,
unsigned int max_entries)
{
char str[KSYM_SYMBOL_LEN];
unsigned int spaces = 8;
unsigned int i;
for (i = 0; i < max_entries; i++) {
if (stacktrace_entries[i] == ULONG_MAX)
return;
seq_printf(m, "%*c", 1 + spaces, ' ');
sprint_symbol(str, stacktrace_entries[i]);
seq_printf(m, "%s\n", str);
}
}
static void
hist_trigger_entry_print(struct seq_file *m,
struct hist_trigger_data *hist_data, void *key,
struct tracing_map_elt *elt)
{
struct hist_field *key_field;
char str[KSYM_SYMBOL_LEN];
bool multiline = false;
unsigned int i;
u64 uval;
seq_puts(m, "{ ");
for_each_hist_key_field(i, hist_data) {
key_field = hist_data->fields[i];
if (i > hist_data->n_vals)
seq_puts(m, ", ");
if (key_field->flags & HIST_FIELD_FL_HEX) {
uval = *(u64 *)(key + key_field->offset);
seq_printf(m, "%s: %llx",
key_field->field->name, uval);
} else if (key_field->flags & HIST_FIELD_FL_SYM) {
uval = *(u64 *)(key + key_field->offset);
sprint_symbol_no_offset(str, uval);
seq_printf(m, "%s: [%llx] %-45s",
key_field->field->name, uval, str);
} else if (key_field->flags & HIST_FIELD_FL_SYM_OFFSET) {
uval = *(u64 *)(key + key_field->offset);
sprint_symbol(str, uval);
seq_printf(m, "%s: [%llx] %-55s",
key_field->field->name, uval, str);
} else if (key_field->flags & HIST_FIELD_FL_EXECNAME) {
char *comm = elt->private_data;
uval = *(u64 *)(key + key_field->offset);
seq_printf(m, "%s: %-16s[%10llu]",
key_field->field->name, comm, uval);
} else if (key_field->flags & HIST_FIELD_FL_SYSCALL) {
const char *syscall_name;
uval = *(u64 *)(key + key_field->offset);
syscall_name = get_syscall_name(uval);
if (!syscall_name)
syscall_name = "unknown_syscall";
seq_printf(m, "%s: %-30s[%3llu]",
key_field->field->name, syscall_name, uval);
} else if (key_field->flags & HIST_FIELD_FL_STACKTRACE) {
seq_puts(m, "stacktrace:\n");
hist_trigger_stacktrace_print(m,
key + key_field->offset,
HIST_STACKTRACE_DEPTH);
multiline = true;
} else if (key_field->flags & HIST_FIELD_FL_LOG2) {
seq_printf(m, "%s: ~ 2^%-2llu", key_field->field->name,
*(u64 *)(key + key_field->offset));
} else if (key_field->flags & HIST_FIELD_FL_STRING) {
seq_printf(m, "%s: %-50s", key_field->field->name,
(char *)(key + key_field->offset));
} else {
uval = *(u64 *)(key + key_field->offset);
seq_printf(m, "%s: %10llu", key_field->field->name,
uval);
}
}
if (!multiline)
seq_puts(m, " ");
seq_puts(m, "}");
seq_printf(m, " hitcount: %10llu",
tracing_map_read_sum(elt, HITCOUNT_IDX));
for (i = 1; i < hist_data->n_vals; i++) {
if (hist_data->fields[i]->flags & HIST_FIELD_FL_HEX) {
seq_printf(m, " %s: %10llx",
hist_data->fields[i]->field->name,
tracing_map_read_sum(elt, i));
} else {
seq_printf(m, " %s: %10llu",
hist_data->fields[i]->field->name,
tracing_map_read_sum(elt, i));
}
}
seq_puts(m, "\n");
}
static int print_entries(struct seq_file *m,
struct hist_trigger_data *hist_data)
{
struct tracing_map_sort_entry **sort_entries = NULL;
struct tracing_map *map = hist_data->map;
int i, n_entries;
n_entries = tracing_map_sort_entries(map, hist_data->sort_keys,
hist_data->n_sort_keys,
&sort_entries);
if (n_entries < 0)
return n_entries;
for (i = 0; i < n_entries; i++)
hist_trigger_entry_print(m, hist_data,
sort_entries[i]->key,
sort_entries[i]->elt);
tracing_map_destroy_sort_entries(sort_entries, n_entries);
return n_entries;
}
static void hist_trigger_show(struct seq_file *m,
struct event_trigger_data *data, int n)
{
struct hist_trigger_data *hist_data;
int n_entries, ret = 0;
if (n > 0)
seq_puts(m, "\n\n");
seq_puts(m, "# event histogram\n#\n# trigger info: ");
data->ops->print(m, data->ops, data);
seq_puts(m, "#\n\n");
hist_data = data->private_data;
n_entries = print_entries(m, hist_data);
if (n_entries < 0) {
ret = n_entries;
n_entries = 0;
}
seq_printf(m, "\nTotals:\n Hits: %llu\n Entries: %u\n Dropped: %llu\n",
(u64)atomic64_read(&hist_data->map->hits),
n_entries, (u64)atomic64_read(&hist_data->map->drops));
}
static int hist_show(struct seq_file *m, void *v)
{
struct event_trigger_data *data;
struct trace_event_file *event_file;
int n = 0, ret = 0;
mutex_lock(&event_mutex);
event_file = event_file_data(m->private);
if (unlikely(!event_file)) {
ret = -ENODEV;
goto out_unlock;
}
list_for_each_entry_rcu(data, &event_file->triggers, list) {
if (data->cmd_ops->trigger_type == ETT_EVENT_HIST)
hist_trigger_show(m, data, n++);
}
out_unlock:
mutex_unlock(&event_mutex);
return ret;
}
static int event_hist_open(struct inode *inode, struct file *file)
{
return single_open(file, hist_show, file);
}
const struct file_operations event_hist_fops = {
.open = event_hist_open,
.read = seq_read,
.llseek = seq_lseek,
.release = single_release,
};
static const char *get_hist_field_flags(struct hist_field *hist_field)
{
const char *flags_str = NULL;
if (hist_field->flags & HIST_FIELD_FL_HEX)
flags_str = "hex";
else if (hist_field->flags & HIST_FIELD_FL_SYM)
flags_str = "sym";
else if (hist_field->flags & HIST_FIELD_FL_SYM_OFFSET)
flags_str = "sym-offset";
else if (hist_field->flags & HIST_FIELD_FL_EXECNAME)
flags_str = "execname";
else if (hist_field->flags & HIST_FIELD_FL_SYSCALL)
flags_str = "syscall";
else if (hist_field->flags & HIST_FIELD_FL_LOG2)
flags_str = "log2";
return flags_str;
}
static void hist_field_print(struct seq_file *m, struct hist_field *hist_field)
{
seq_printf(m, "%s", hist_field->field->name);
if (hist_field->flags) {
const char *flags_str = get_hist_field_flags(hist_field);
if (flags_str)
seq_printf(m, ".%s", flags_str);
}
}
static int event_hist_trigger_print(struct seq_file *m,
struct event_trigger_ops *ops,
struct event_trigger_data *data)
{
struct hist_trigger_data *hist_data = data->private_data;
struct hist_field *key_field;
unsigned int i;
seq_puts(m, "hist:");
if (data->name)
seq_printf(m, "%s:", data->name);
seq_puts(m, "keys=");
for_each_hist_key_field(i, hist_data) {
key_field = hist_data->fields[i];
if (i > hist_data->n_vals)
seq_puts(m, ",");
if (key_field->flags & HIST_FIELD_FL_STACKTRACE)
seq_puts(m, "stacktrace");
else
hist_field_print(m, key_field);
}
seq_puts(m, ":vals=");
for_each_hist_val_field(i, hist_data) {
if (i == HITCOUNT_IDX)
seq_puts(m, "hitcount");
else {
seq_puts(m, ",");
hist_field_print(m, hist_data->fields[i]);
}
}
seq_puts(m, ":sort=");
for (i = 0; i < hist_data->n_sort_keys; i++) {
struct tracing_map_sort_key *sort_key;
sort_key = &hist_data->sort_keys[i];
if (i > 0)
seq_puts(m, ",");
if (sort_key->field_idx == HITCOUNT_IDX)
seq_puts(m, "hitcount");
else {
unsigned int idx = sort_key->field_idx;
if (WARN_ON(idx >= TRACING_MAP_FIELDS_MAX))
return -EINVAL;
hist_field_print(m, hist_data->fields[idx]);
}
if (sort_key->descending)
seq_puts(m, ".descending");
}
seq_printf(m, ":size=%u", (1 << hist_data->map->map_bits));
if (data->filter_str)
seq_printf(m, " if %s", data->filter_str);
if (data->paused)
seq_puts(m, " [paused]");
else
seq_puts(m, " [active]");
seq_putc(m, '\n');
return 0;
}
static int event_hist_trigger_init(struct event_trigger_ops *ops,
struct event_trigger_data *data)
{
struct hist_trigger_data *hist_data = data->private_data;
if (!data->ref && hist_data->attrs->name)
save_named_trigger(hist_data->attrs->name, data);
data->ref++;
return 0;
}
static void event_hist_trigger_free(struct event_trigger_ops *ops,
struct event_trigger_data *data)
{
struct hist_trigger_data *hist_data = data->private_data;
if (WARN_ON_ONCE(data->ref <= 0))
return;
data->ref--;
if (!data->ref) {
if (data->name)
del_named_trigger(data);
trigger_data_free(data);
destroy_hist_data(hist_data);
}
}
static struct event_trigger_ops event_hist_trigger_ops = {
.func = event_hist_trigger,
.print = event_hist_trigger_print,
.init = event_hist_trigger_init,
.free = event_hist_trigger_free,
};
static int event_hist_trigger_named_init(struct event_trigger_ops *ops,
struct event_trigger_data *data)
{
data->ref++;
save_named_trigger(data->named_data->name, data);
event_hist_trigger_init(ops, data->named_data);
return 0;
}
static void event_hist_trigger_named_free(struct event_trigger_ops *ops,
struct event_trigger_data *data)
{
if (WARN_ON_ONCE(data->ref <= 0))
return;
event_hist_trigger_free(ops, data->named_data);
data->ref--;
if (!data->ref) {
del_named_trigger(data);
trigger_data_free(data);
}
}
static struct event_trigger_ops event_hist_trigger_named_ops = {
.func = event_hist_trigger,
.print = event_hist_trigger_print,
.init = event_hist_trigger_named_init,
.free = event_hist_trigger_named_free,
};
static struct event_trigger_ops *event_hist_get_trigger_ops(char *cmd,
char *param)
{
return &event_hist_trigger_ops;
}
static void hist_clear(struct event_trigger_data *data)
{
struct hist_trigger_data *hist_data = data->private_data;
if (data->name)
pause_named_trigger(data);
synchronize_sched();
tracing_map_clear(hist_data->map);
if (data->name)
unpause_named_trigger(data);
}
static bool compatible_field(struct ftrace_event_field *field,
struct ftrace_event_field *test_field)
{
if (field == test_field)
return true;
if (field == NULL || test_field == NULL)
return false;
if (strcmp(field->name, test_field->name) != 0)
return false;
if (strcmp(field->type, test_field->type) != 0)
return false;
if (field->size != test_field->size)
return false;
if (field->is_signed != test_field->is_signed)
return false;
return true;
}
static bool hist_trigger_match(struct event_trigger_data *data,
struct event_trigger_data *data_test,
struct event_trigger_data *named_data,
bool ignore_filter)
{
struct tracing_map_sort_key *sort_key, *sort_key_test;
struct hist_trigger_data *hist_data, *hist_data_test;
struct hist_field *key_field, *key_field_test;
unsigned int i;
if (named_data && (named_data != data_test) &&
(named_data != data_test->named_data))
return false;
if (!named_data && is_named_trigger(data_test))
return false;
hist_data = data->private_data;
hist_data_test = data_test->private_data;
if (hist_data->n_vals != hist_data_test->n_vals ||
hist_data->n_fields != hist_data_test->n_fields ||
hist_data->n_sort_keys != hist_data_test->n_sort_keys)
return false;
if (!ignore_filter) {
if ((data->filter_str && !data_test->filter_str) ||
(!data->filter_str && data_test->filter_str))
return false;
}
for_each_hist_field(i, hist_data) {
key_field = hist_data->fields[i];
key_field_test = hist_data_test->fields[i];
if (key_field->flags != key_field_test->flags)
return false;
if (!compatible_field(key_field->field, key_field_test->field))
return false;
if (key_field->offset != key_field_test->offset)
return false;
}
for (i = 0; i < hist_data->n_sort_keys; i++) {
sort_key = &hist_data->sort_keys[i];
sort_key_test = &hist_data_test->sort_keys[i];
if (sort_key->field_idx != sort_key_test->field_idx ||
sort_key->descending != sort_key_test->descending)
return false;
}
if (!ignore_filter && data->filter_str &&
(strcmp(data->filter_str, data_test->filter_str) != 0))
return false;
return true;
}
static int hist_register_trigger(char *glob, struct event_trigger_ops *ops,
struct event_trigger_data *data,
struct trace_event_file *file)
{
struct hist_trigger_data *hist_data = data->private_data;
struct event_trigger_data *test, *named_data = NULL;
int ret = 0;
if (hist_data->attrs->name) {
named_data = find_named_trigger(hist_data->attrs->name);
if (named_data) {
if (!hist_trigger_match(data, named_data, named_data,
true)) {
ret = -EINVAL;
goto out;
}
}
}
if (hist_data->attrs->name && !named_data)
goto new;
list_for_each_entry_rcu(test, &file->triggers, list) {
if (test->cmd_ops->trigger_type == ETT_EVENT_HIST) {
if (!hist_trigger_match(data, test, named_data, false))
continue;
if (hist_data->attrs->pause)
test->paused = true;
else if (hist_data->attrs->cont)
test->paused = false;
else if (hist_data->attrs->clear)
hist_clear(test);
else
ret = -EEXIST;
goto out;
}
}
new:
if (hist_data->attrs->cont || hist_data->attrs->clear) {
ret = -ENOENT;
goto out;
}
if (named_data) {
destroy_hist_data(data->private_data);
data->private_data = named_data->private_data;
set_named_trigger_data(data, named_data);
data->ops = &event_hist_trigger_named_ops;
}
if (hist_data->attrs->pause)
data->paused = true;
if (data->ops->init) {
ret = data->ops->init(data->ops, data);
if (ret < 0)
goto out;
}
list_add_rcu(&data->list, &file->triggers);
ret++;
update_cond_flag(file);
if (trace_event_trigger_enable_disable(file, 1) < 0) {
list_del_rcu(&data->list);
update_cond_flag(file);
ret--;
}
out:
return ret;
}
static void hist_unregister_trigger(char *glob, struct event_trigger_ops *ops,
struct event_trigger_data *data,
struct trace_event_file *file)
{
struct hist_trigger_data *hist_data = data->private_data;
struct event_trigger_data *test, *named_data = NULL;
bool unregistered = false;
if (hist_data->attrs->name)
named_data = find_named_trigger(hist_data->attrs->name);
list_for_each_entry_rcu(test, &file->triggers, list) {
if (test->cmd_ops->trigger_type == ETT_EVENT_HIST) {
if (!hist_trigger_match(data, test, named_data, false))
continue;
unregistered = true;
list_del_rcu(&test->list);
trace_event_trigger_enable_disable(file, 0);
update_cond_flag(file);
break;
}
}
if (unregistered && test->ops->free)
test->ops->free(test->ops, test);
}
static void hist_unreg_all(struct trace_event_file *file)
{
struct event_trigger_data *test;
list_for_each_entry_rcu(test, &file->triggers, list) {
if (test->cmd_ops->trigger_type == ETT_EVENT_HIST) {
list_del_rcu(&test->list);
trace_event_trigger_enable_disable(file, 0);
update_cond_flag(file);
if (test->ops->free)
test->ops->free(test->ops, test);
}
}
}
static int event_hist_trigger_func(struct event_command *cmd_ops,
struct trace_event_file *file,
char *glob, char *cmd, char *param)
{
unsigned int hist_trigger_bits = TRACING_MAP_BITS_DEFAULT;
struct event_trigger_data *trigger_data;
struct hist_trigger_attrs *attrs;
struct event_trigger_ops *trigger_ops;
struct hist_trigger_data *hist_data;
char *trigger;
int ret = 0;
if (!param)
return -EINVAL;
/* separate the trigger from the filter (k:v [if filter]) */
trigger = strsep(&param, " \t");
if (!trigger)
return -EINVAL;
attrs = parse_hist_trigger_attrs(trigger);
if (IS_ERR(attrs))
return PTR_ERR(attrs);
if (attrs->map_bits)
hist_trigger_bits = attrs->map_bits;
hist_data = create_hist_data(hist_trigger_bits, attrs, file);
if (IS_ERR(hist_data)) {
destroy_hist_trigger_attrs(attrs);
return PTR_ERR(hist_data);
}
trigger_ops = cmd_ops->get_trigger_ops(cmd, trigger);
ret = -ENOMEM;
trigger_data = kzalloc(sizeof(*trigger_data), GFP_KERNEL);
if (!trigger_data)
goto out_free;
trigger_data->count = -1;
trigger_data->ops = trigger_ops;
trigger_data->cmd_ops = cmd_ops;
INIT_LIST_HEAD(&trigger_data->list);
RCU_INIT_POINTER(trigger_data->filter, NULL);
trigger_data->private_data = hist_data;
/* if param is non-empty, it's supposed to be a filter */
if (param && cmd_ops->set_filter) {
ret = cmd_ops->set_filter(param, trigger_data, file);
if (ret < 0)
goto out_free;
}
if (glob[0] == '!') {
cmd_ops->unreg(glob+1, trigger_ops, trigger_data, file);
ret = 0;
goto out_free;
}
ret = cmd_ops->reg(glob, trigger_ops, trigger_data, file);
/*
* The above returns on success the # of triggers registered,
* but if it didn't register any it returns zero. Consider no
* triggers registered a failure too.
*/
if (!ret) {
if (!(attrs->pause || attrs->cont || attrs->clear))
ret = -ENOENT;
goto out_free;
} else if (ret < 0)
goto out_free;
/* Just return zero, not the number of registered triggers */
ret = 0;
out:
return ret;
out_free:
if (cmd_ops->set_filter)
cmd_ops->set_filter(NULL, trigger_data, NULL);
kfree(trigger_data);
destroy_hist_data(hist_data);
goto out;
}
static struct event_command trigger_hist_cmd = {
.name = "hist",
.trigger_type = ETT_EVENT_HIST,
.flags = EVENT_CMD_FL_NEEDS_REC,
.func = event_hist_trigger_func,
.reg = hist_register_trigger,
.unreg = hist_unregister_trigger,
.unreg_all = hist_unreg_all,
.get_trigger_ops = event_hist_get_trigger_ops,
.set_filter = set_trigger_filter,
};
__init int register_trigger_hist_cmd(void)
{
int ret;
ret = register_event_command(&trigger_hist_cmd);
WARN_ON(ret < 0);
return ret;
}
static void
hist_enable_trigger(struct event_trigger_data *data, void *rec)
{
struct enable_trigger_data *enable_data = data->private_data;
struct event_trigger_data *test;
list_for_each_entry_rcu(test, &enable_data->file->triggers, list) {
if (test->cmd_ops->trigger_type == ETT_EVENT_HIST) {
if (enable_data->enable)
test->paused = false;
else
test->paused = true;
}
}
}
static void
hist_enable_count_trigger(struct event_trigger_data *data, void *rec)
{
if (!data->count)
return;
if (data->count != -1)
(data->count)--;
hist_enable_trigger(data, rec);
}
static struct event_trigger_ops hist_enable_trigger_ops = {
.func = hist_enable_trigger,
.print = event_enable_trigger_print,
.init = event_trigger_init,
.free = event_enable_trigger_free,
};
static struct event_trigger_ops hist_enable_count_trigger_ops = {
.func = hist_enable_count_trigger,
.print = event_enable_trigger_print,
.init = event_trigger_init,
.free = event_enable_trigger_free,
};
static struct event_trigger_ops hist_disable_trigger_ops = {
.func = hist_enable_trigger,
.print = event_enable_trigger_print,
.init = event_trigger_init,
.free = event_enable_trigger_free,
};
static struct event_trigger_ops hist_disable_count_trigger_ops = {
.func = hist_enable_count_trigger,
.print = event_enable_trigger_print,
.init = event_trigger_init,
.free = event_enable_trigger_free,
};
static struct event_trigger_ops *
hist_enable_get_trigger_ops(char *cmd, char *param)
{
struct event_trigger_ops *ops;
bool enable;
enable = (strcmp(cmd, ENABLE_HIST_STR) == 0);
if (enable)
ops = param ? &hist_enable_count_trigger_ops :
&hist_enable_trigger_ops;
else
ops = param ? &hist_disable_count_trigger_ops :
&hist_disable_trigger_ops;
return ops;
}
static void hist_enable_unreg_all(struct trace_event_file *file)
{
struct event_trigger_data *test;
list_for_each_entry_rcu(test, &file->triggers, list) {
if (test->cmd_ops->trigger_type == ETT_HIST_ENABLE) {
list_del_rcu(&test->list);
update_cond_flag(file);
trace_event_trigger_enable_disable(file, 0);
if (test->ops->free)
test->ops->free(test->ops, test);
}
}
}
static struct event_command trigger_hist_enable_cmd = {
.name = ENABLE_HIST_STR,
.trigger_type = ETT_HIST_ENABLE,
.func = event_enable_trigger_func,
.reg = event_enable_register_trigger,
.unreg = event_enable_unregister_trigger,
.unreg_all = hist_enable_unreg_all,
.get_trigger_ops = hist_enable_get_trigger_ops,
.set_filter = set_trigger_filter,
};
static struct event_command trigger_hist_disable_cmd = {
.name = DISABLE_HIST_STR,
.trigger_type = ETT_HIST_ENABLE,
.func = event_enable_trigger_func,
.reg = event_enable_register_trigger,
.unreg = event_enable_unregister_trigger,
.unreg_all = hist_enable_unreg_all,
.get_trigger_ops = hist_enable_get_trigger_ops,
.set_filter = set_trigger_filter,
};
static __init void unregister_trigger_hist_enable_disable_cmds(void)
{
unregister_event_command(&trigger_hist_enable_cmd);
unregister_event_command(&trigger_hist_disable_cmd);
}
__init int register_trigger_hist_enable_disable_cmds(void)
{
int ret;
ret = register_event_command(&trigger_hist_enable_cmd);
if (WARN_ON(ret < 0))
return ret;
ret = register_event_command(&trigger_hist_disable_cmd);
if (WARN_ON(ret < 0))
unregister_trigger_hist_enable_disable_cmds();
return ret;
}
kernel/trace/trace_events_trigger.c
View file @ 2600a46e
......@@ -347,7 +347,7 @@ __init int register_event_command(struct event_command *cmd)
* Currently we only unregister event commands from __init, so mark
* this __init too.
*/
static __init int unregister_event_command(struct event_command *cmd)
__init int unregister_event_command(struct event_command *cmd)
{
struct event_command *p, *n;
int ret = -ENODEV;
......@@ -641,6 +641,7 @@ event_trigger_callback(struct event_command *cmd_ops,
trigger_data->ops = trigger_ops;
trigger_data->cmd_ops = cmd_ops;
INIT_LIST_HEAD(&trigger_data->list);
INIT_LIST_HEAD(&trigger_data->named_list);
if (glob[0] == '!') {
cmd_ops->unreg(glob+1, trigger_ops, trigger_data, file);
......@@ -764,6 +765,148 @@ int set_trigger_filter(char *filter_str,
return ret;
}
static LIST_HEAD(named_triggers);
/**
* find_named_trigger - Find the common named trigger associated with @name
* @name: The name of the set of named triggers to find the common data for
*
* Named triggers are sets of triggers that share a common set of
* trigger data. The first named trigger registered with a given name
* owns the common trigger data that the others subsequently
* registered with the same name will reference. This function
* returns the common trigger data associated with that first
* registered instance.
*
* Return: the common trigger data for the given named trigger on
* success, NULL otherwise.
*/
struct event_trigger_data *find_named_trigger(const char *name)
{
struct event_trigger_data *data;
if (!name)
return NULL;
list_for_each_entry(data, &named_triggers, named_list) {
if (data->named_data)
continue;
if (strcmp(data->name, name) == 0)
return data;
}
return NULL;
}
/**
* is_named_trigger - determine if a given trigger is a named trigger
* @test: The trigger data to test
*
* Return: true if 'test' is a named trigger, false otherwise.
*/
bool is_named_trigger(struct event_trigger_data *test)
{
struct event_trigger_data *data;
list_for_each_entry(data, &named_triggers, named_list) {
if (test == data)
return true;
}
return false;
}
/**
* save_named_trigger - save the trigger in the named trigger list
* @name: The name of the named trigger set
* @data: The trigger data to save
*
* Return: 0 if successful, negative error otherwise.
*/
int save_named_trigger(const char *name, struct event_trigger_data *data)
{
data->name = kstrdup(name, GFP_KERNEL);
if (!data->name)
return -ENOMEM;
list_add(&data->named_list, &named_triggers);
return 0;
}
/**
* del_named_trigger - delete a trigger from the named trigger list
* @data: The trigger data to delete
*/
void del_named_trigger(struct event_trigger_data *data)
{
kfree(data->name);
data->name = NULL;
list_del(&data->named_list);
}
static void __pause_named_trigger(struct event_trigger_data *data, bool pause)
{
struct event_trigger_data *test;
list_for_each_entry(test, &named_triggers, named_list) {
if (strcmp(test->name, data->name) == 0) {
if (pause) {
test->paused_tmp = test->paused;
test->paused = true;
} else {
test->paused = test->paused_tmp;
}
}
}
}
/**
* pause_named_trigger - Pause all named triggers with the same name
* @data: The trigger data of a named trigger to pause
*
* Pauses a named trigger along with all other triggers having the
* same name. Because named triggers share a common set of data,
* pausing only one is meaningless, so pausing one named trigger needs
* to pause all triggers with the same name.
*/
void pause_named_trigger(struct event_trigger_data *data)
{
__pause_named_trigger(data, true);
}
/**
* unpause_named_trigger - Un-pause all named triggers with the same name
* @data: The trigger data of a named trigger to unpause
*
* Un-pauses a named trigger along with all other triggers having the
* same name. Because named triggers share a common set of data,
* unpausing only one is meaningless, so unpausing one named trigger
* needs to unpause all triggers with the same name.
*/
void unpause_named_trigger(struct event_trigger_data *data)
{
__pause_named_trigger(data, false);
}
/**
* set_named_trigger_data - Associate common named trigger data
* @data: The trigger data of a named trigger to unpause
*
* Named triggers are sets of triggers that share a common set of
* trigger data. The first named trigger registered with a given name
* owns the common trigger data that the others subsequently
* registered with the same name will reference. This function
* associates the common trigger data from the first trigger with the
* given trigger.
*/
void set_named_trigger_data(struct event_trigger_data *data,
struct event_trigger_data *named_data)
{
data->named_data = named_data;
}
static void
traceon_trigger(struct event_trigger_data *data, void *rec)
{
......@@ -1062,15 +1205,6 @@ static __init void unregister_trigger_traceon_traceoff_cmds(void)
unregister_event_command(&trigger_traceoff_cmd);
}
/* Avoid typos */
#define ENABLE_EVENT_STR "enable_event"
#define DISABLE_EVENT_STR "disable_event"
struct enable_trigger_data {
struct trace_event_file *file;
bool enable;
};
static void
event_enable_trigger(struct event_trigger_data *data, void *rec)
{
......@@ -1100,14 +1234,16 @@ event_enable_count_trigger(struct event_trigger_data *data, void *rec)
event_enable_trigger(data, rec);
}
static int
event_enable_trigger_print(struct seq_file *m, struct event_trigger_ops *ops,
struct event_trigger_data *data)
int event_enable_trigger_print(struct seq_file *m,
struct event_trigger_ops *ops,
struct event_trigger_data *data)
{
struct enable_trigger_data *enable_data = data->private_data;
seq_printf(m, "%s:%s:%s",
enable_data->enable ? ENABLE_EVENT_STR : DISABLE_EVENT_STR,
enable_data->hist ?
(enable_data->enable ? ENABLE_HIST_STR : DISABLE_HIST_STR) :
(enable_data->enable ? ENABLE_EVENT_STR : DISABLE_EVENT_STR),
enable_data->file->event_call->class->system,
trace_event_name(enable_data->file->event_call));
......@@ -1124,9 +1260,8 @@ event_enable_trigger_print(struct seq_file *m, struct event_trigger_ops *ops,
return 0;
}
static void
event_enable_trigger_free(struct event_trigger_ops *ops,
struct event_trigger_data *data)
void event_enable_trigger_free(struct event_trigger_ops *ops,
struct event_trigger_data *data)
{
struct enable_trigger_data *enable_data = data->private_data;
......@@ -1171,10 +1306,9 @@ static struct event_trigger_ops event_disable_count_trigger_ops = {
.free = event_enable_trigger_free,
};
static int
event_enable_trigger_func(struct event_command *cmd_ops,
struct trace_event_file *file,
char *glob, char *cmd, char *param)
int event_enable_trigger_func(struct event_command *cmd_ops,
struct trace_event_file *file,
char *glob, char *cmd, char *param)
{
struct trace_event_file *event_enable_file;
struct enable_trigger_data *enable_data;
......@@ -1183,6 +1317,7 @@ event_enable_trigger_func(struct event_command *cmd_ops,
struct trace_array *tr = file->tr;
const char *system;
const char *event;
bool hist = false;
char *trigger;
char *number;
bool enable;
......@@ -1207,8 +1342,15 @@ event_enable_trigger_func(struct event_command *cmd_ops,
if (!event_enable_file)
goto out;
enable = strcmp(cmd, ENABLE_EVENT_STR) == 0;
#ifdef CONFIG_HIST_TRIGGERS
hist = ((strcmp(cmd, ENABLE_HIST_STR) == 0) ||
(strcmp(cmd, DISABLE_HIST_STR) == 0));
enable = ((strcmp(cmd, ENABLE_EVENT_STR) == 0) ||
(strcmp(cmd, ENABLE_HIST_STR) == 0));
#else
enable = strcmp(cmd, ENABLE_EVENT_STR) == 0;
#endif
trigger_ops = cmd_ops->get_trigger_ops(cmd, trigger);
ret = -ENOMEM;
......@@ -1228,6 +1370,7 @@ event_enable_trigger_func(struct event_command *cmd_ops,
INIT_LIST_HEAD(&trigger_data->list);
RCU_INIT_POINTER(trigger_data->filter, NULL);
enable_data->hist = hist;
enable_data->enable = enable;
enable_data->file = event_enable_file;
trigger_data->private_data = enable_data;
......@@ -1305,10 +1448,10 @@ event_enable_trigger_func(struct event_command *cmd_ops,
goto out;
}
static int event_enable_register_trigger(char *glob,
struct event_trigger_ops *ops,
struct event_trigger_data *data,
struct trace_event_file *file)
int event_enable_register_trigger(char *glob,
struct event_trigger_ops *ops,
struct event_trigger_data *data,
struct trace_event_file *file)
{
struct enable_trigger_data *enable_data = data->private_data;
struct enable_trigger_data *test_enable_data;
......@@ -1318,6 +1461,8 @@ static int event_enable_register_trigger(char *glob,
list_for_each_entry_rcu(test, &file->triggers, list) {
test_enable_data = test->private_data;
if (test_enable_data &&
(test->cmd_ops->trigger_type ==
data->cmd_ops->trigger_type) &&
(test_enable_data->file == enable_data->file)) {
ret = -EEXIST;
goto out;
......@@ -1343,10 +1488,10 @@ static int event_enable_register_trigger(char *glob,
return ret;
}
static void event_enable_unregister_trigger(char *glob,
struct event_trigger_ops *ops,
struct event_trigger_data *test,
struct trace_event_file *file)
void event_enable_unregister_trigger(char *glob,
struct event_trigger_ops *ops,
struct event_trigger_data *test,
struct trace_event_file *file)
{
struct enable_trigger_data *test_enable_data = test->private_data;
struct enable_trigger_data *enable_data;
......@@ -1356,6 +1501,8 @@ static void event_enable_unregister_trigger(char *glob,
list_for_each_entry_rcu(data, &file->triggers, list) {
enable_data = data->private_data;
if (enable_data &&
(data->cmd_ops->trigger_type ==
test->cmd_ops->trigger_type) &&
(enable_data->file == test_enable_data->file)) {
unregistered = true;
list_del_rcu(&data->list);
......@@ -1375,8 +1522,12 @@ event_enable_get_trigger_ops(char *cmd, char *param)
struct event_trigger_ops *ops;
bool enable;
#ifdef CONFIG_HIST_TRIGGERS
enable = ((strcmp(cmd, ENABLE_EVENT_STR) == 0) ||
(strcmp(cmd, ENABLE_HIST_STR) == 0));
#else
enable = strcmp(cmd, ENABLE_EVENT_STR) == 0;
#endif
if (enable)
ops = param ? &event_enable_count_trigger_ops :
&event_enable_trigger_ops;
......@@ -1447,6 +1598,8 @@ __init int register_trigger_cmds(void)
register_trigger_snapshot_cmd();
register_trigger_stacktrace_cmd();
register_trigger_enable_disable_cmds();
register_trigger_hist_enable_disable_cmds();
register_trigger_hist_cmd();
return 0;
}
kernel/trace/tracing_map.c 0 → 100644
View file @ 2600a46e
/*
* tracing_map - lock-free map for tracing
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* Copyright (C) 2015 Tom Zanussi <tom.zanussi@linux.intel.com>
*
* tracing_map implementation inspired by lock-free map algorithms
* originated by Dr. Cliff Click:
*
* http://www.azulsystems.com/blog/cliff/2007-03-26-non-blocking-hashtable
* http://www.azulsystems.com/events/javaone_2007/2007_LockFreeHash.pdf
*/
#include <linux/vmalloc.h>
#include <linux/jhash.h>
#include <linux/slab.h>
#include <linux/sort.h>
#include "tracing_map.h"
#include "trace.h"
/*
* NOTE: For a detailed description of the data structures used by
* these functions (such as tracing_map_elt) please see the overview
* of tracing_map data structures at the beginning of tracing_map.h.
*/
/**
* tracing_map_update_sum - Add a value to a tracing_map_elt's sum field
* @elt: The tracing_map_elt
* @i: The index of the given sum associated with the tracing_map_elt
* @n: The value to add to the sum
*
* Add n to sum i associated with the specified tracing_map_elt
* instance. The index i is the index returned by the call to
* tracing_map_add_sum_field() when the tracing map was set up.
*/
void tracing_map_update_sum(struct tracing_map_elt *elt, unsigned int i, u64 n)
{
atomic64_add(n, &elt->fields[i].sum);
}
/**
* tracing_map_read_sum - Return the value of a tracing_map_elt's sum field
* @elt: The tracing_map_elt
* @i: The index of the given sum associated with the tracing_map_elt
*
* Retrieve the value of the sum i associated with the specified
* tracing_map_elt instance. The index i is the index returned by the
* call to tracing_map_add_sum_field() when the tracing map was set
* up.
*
* Return: The sum associated with field i for elt.
*/
u64 tracing_map_read_sum(struct tracing_map_elt *elt, unsigned int i)
{
return (u64)atomic64_read(&elt->fields[i].sum);
}
int tracing_map_cmp_string(void *val_a, void *val_b)
{
char *a = val_a;
char *b = val_b;
return strcmp(a, b);
}
int tracing_map_cmp_none(void *val_a, void *val_b)
{
return 0;
}
static int tracing_map_cmp_atomic64(void *val_a, void *val_b)
{
u64 a = atomic64_read((atomic64_t *)val_a);
u64 b = atomic64_read((atomic64_t *)val_b);
return (a > b) ? 1 : ((a < b) ? -1 : 0);
}
#define DEFINE_TRACING_MAP_CMP_FN(type) \
static int tracing_map_cmp_##type(void *val_a, void *val_b) \
{ \
type a = *(type *)val_a; \
type b = *(type *)val_b; \
\
return (a > b) ? 1 : ((a < b) ? -1 : 0); \
}
DEFINE_TRACING_MAP_CMP_FN(s64);
DEFINE_TRACING_MAP_CMP_FN(u64);
DEFINE_TRACING_MAP_CMP_FN(s32);
DEFINE_TRACING_MAP_CMP_FN(u32);
DEFINE_TRACING_MAP_CMP_FN(s16);
DEFINE_TRACING_MAP_CMP_FN(u16);
DEFINE_TRACING_MAP_CMP_FN(s8);
DEFINE_TRACING_MAP_CMP_FN(u8);
tracing_map_cmp_fn_t tracing_map_cmp_num(int field_size,
int field_is_signed)
{
tracing_map_cmp_fn_t fn = tracing_map_cmp_none;
switch (field_size) {
case 8:
if (field_is_signed)
fn = tracing_map_cmp_s64;
else
fn = tracing_map_cmp_u64;
break;
case 4:
if (field_is_signed)
fn = tracing_map_cmp_s32;
else
fn = tracing_map_cmp_u32;
break;
case 2:
if (field_is_signed)
fn = tracing_map_cmp_s16;
else
fn = tracing_map_cmp_u16;
break;
case 1:
if (field_is_signed)
fn = tracing_map_cmp_s8;
else
fn = tracing_map_cmp_u8;
break;
}
return fn;
}
static int tracing_map_add_field(struct tracing_map *map,
tracing_map_cmp_fn_t cmp_fn)
{
int ret = -EINVAL;
if (map->n_fields < TRACING_MAP_FIELDS_MAX) {
ret = map->n_fields;
map->fields[map->n_fields++].cmp_fn = cmp_fn;
}
return ret;
}
/**
* tracing_map_add_sum_field - Add a field describing a tracing_map sum
* @map: The tracing_map
*
* Add a sum field to the key and return the index identifying it in
* the map and associated tracing_map_elts. This is the index used
* for instance to update a sum for a particular tracing_map_elt using
* tracing_map_update_sum() or reading it via tracing_map_read_sum().
*
* Return: The index identifying the field in the map and associated
* tracing_map_elts, or -EINVAL on error.
*/
int tracing_map_add_sum_field(struct tracing_map *map)
{
return tracing_map_add_field(map, tracing_map_cmp_atomic64);
}
/**
* tracing_map_add_key_field - Add a field describing a tracing_map key
* @map: The tracing_map
* @offset: The offset within the key
* @cmp_fn: The comparison function that will be used to sort on the key
*
* Let the map know there is a key and that if it's used as a sort key
* to use cmp_fn.
*
* A key can be a subset of a compound key; for that purpose, the
* offset param is used to describe where within the the compound key
* the key referenced by this key field resides.
*
* Return: The index identifying the field in the map and associated
* tracing_map_elts, or -EINVAL on error.
*/
int tracing_map_add_key_field(struct tracing_map *map,
unsigned int offset,
tracing_map_cmp_fn_t cmp_fn)
{
int idx = tracing_map_add_field(map, cmp_fn);
if (idx < 0)
return idx;
map->fields[idx].offset = offset;
map->key_idx[map->n_keys++] = idx;
return idx;
}
void tracing_map_array_clear(struct tracing_map_array *a)
{
unsigned int i;
if (!a->pages)
return;
for (i = 0; i < a->n_pages; i++)
memset(a->pages[i], 0, PAGE_SIZE);
}
void tracing_map_array_free(struct tracing_map_array *a)
{
unsigned int i;
if (!a)
return;
if (!a->pages) {
kfree(a);
return;
}
for (i = 0; i < a->n_pages; i++) {
if (!a->pages[i])
break;
free_page((unsigned long)a->pages[i]);
}
}
struct tracing_map_array *tracing_map_array_alloc(unsigned int n_elts,
unsigned int entry_size)
{
struct tracing_map_array *a;
unsigned int i;
a = kzalloc(sizeof(*a), GFP_KERNEL);
if (!a)
return NULL;
a->entry_size_shift = fls(roundup_pow_of_two(entry_size) - 1);
a->entries_per_page = PAGE_SIZE / (1 << a->entry_size_shift);
a->n_pages = n_elts / a->entries_per_page;
if (!a->n_pages)
a->n_pages = 1;
a->entry_shift = fls(a->entries_per_page) - 1;
a->entry_mask = (1 << a->entry_shift) - 1;
a->pages = kcalloc(a->n_pages, sizeof(void *), GFP_KERNEL);
if (!a->pages)
goto free;
for (i = 0; i < a->n_pages; i++) {
a->pages[i] = (void *)get_zeroed_page(GFP_KERNEL);
if (!a->pages[i])
goto free;
}
out:
return a;
free:
tracing_map_array_free(a);
a = NULL;
goto out;
}
static void tracing_map_elt_clear(struct tracing_map_elt *elt)
{
unsigned i;
for (i = 0; i < elt->map->n_fields; i++)
if (elt->fields[i].cmp_fn == tracing_map_cmp_atomic64)
atomic64_set(&elt->fields[i].sum, 0);
if (elt->map->ops && elt->map->ops->elt_clear)
elt->map->ops->elt_clear(elt);
}
static void tracing_map_elt_init_fields(struct tracing_map_elt *elt)
{
unsigned int i;
tracing_map_elt_clear(elt);
for (i = 0; i < elt->map->n_fields; i++) {
elt->fields[i].cmp_fn = elt->map->fields[i].cmp_fn;
if (elt->fields[i].cmp_fn != tracing_map_cmp_atomic64)
elt->fields[i].offset = elt->map->fields[i].offset;
}
}
static void tracing_map_elt_free(struct tracing_map_elt *elt)
{
if (!elt)
return;
if (elt->map->ops && elt->map->ops->elt_free)
elt->map->ops->elt_free(elt);
kfree(elt->fields);
kfree(elt->key);
kfree(elt);
}
static struct tracing_map_elt *tracing_map_elt_alloc(struct tracing_map *map)
{
struct tracing_map_elt *elt;
int err = 0;
elt = kzalloc(sizeof(*elt), GFP_KERNEL);
if (!elt)
return ERR_PTR(-ENOMEM);
elt->map = map;
elt->key = kzalloc(map->key_size, GFP_KERNEL);
if (!elt->key) {
err = -ENOMEM;
goto free;
}
elt->fields = kcalloc(map->n_fields, sizeof(*elt->fields), GFP_KERNEL);
if (!elt->fields) {
err = -ENOMEM;
goto free;
}
tracing_map_elt_init_fields(elt);
if (map->ops && map->ops->elt_alloc) {
err = map->ops->elt_alloc(elt);
if (err)
goto free;
}
return elt;
free:
tracing_map_elt_free(elt);
return ERR_PTR(err);
}
static struct tracing_map_elt *get_free_elt(struct tracing_map *map)
{
struct tracing_map_elt *elt = NULL;
int idx;
idx = atomic_inc_return(&map->next_elt);
if (idx < map->max_elts) {
elt = *(TRACING_MAP_ELT(map->elts, idx));
if (map->ops && map->ops->elt_init)
map->ops->elt_init(elt);
}
return elt;
}
static void tracing_map_free_elts(struct tracing_map *map)
{
unsigned int i;
if (!map->elts)
return;
for (i = 0; i < map->max_elts; i++) {
tracing_map_elt_free(*(TRACING_MAP_ELT(map->elts, i)));
*(TRACING_MAP_ELT(map->elts, i)) = NULL;
}
tracing_map_array_free(map->elts);
map->elts = NULL;
}
static int tracing_map_alloc_elts(struct tracing_map *map)
{
unsigned int i;
map->elts = tracing_map_array_alloc(map->max_elts,
sizeof(struct tracing_map_elt *));
if (!map->elts)
return -ENOMEM;
for (i = 0; i < map->max_elts; i++) {
*(TRACING_MAP_ELT(map->elts, i)) = tracing_map_elt_alloc(map);
if (IS_ERR(*(TRACING_MAP_ELT(map->elts, i)))) {
*(TRACING_MAP_ELT(map->elts, i)) = NULL;
tracing_map_free_elts(map);
return -ENOMEM;
}
}
return 0;
}
static inline bool keys_match(void *key, void *test_key, unsigned key_size)
{
bool match = true;
if (memcmp(key, test_key, key_size))
match = false;
return match;
}
static inline struct tracing_map_elt *
__tracing_map_insert(struct tracing_map *map, void *key, bool lookup_only)
{
u32 idx, key_hash, test_key;
struct tracing_map_entry *entry;
key_hash = jhash(key, map->key_size, 0);
if (key_hash == 0)
key_hash = 1;
idx = key_hash >> (32 - (map->map_bits + 1));
while (1) {
idx &= (map->map_size - 1);
entry = TRACING_MAP_ENTRY(map->map, idx);
test_key = entry->key;
if (test_key && test_key == key_hash && entry->val &&
keys_match(key, entry->val->key, map->key_size)) {
atomic64_inc(&map->hits);
return entry->val;
}
if (!test_key) {
if (lookup_only)
break;
if (!cmpxchg(&entry->key, 0, key_hash)) {
struct tracing_map_elt *elt;
elt = get_free_elt(map);
if (!elt) {
atomic64_inc(&map->drops);
entry->key = 0;
break;
}
memcpy(elt->key, key, map->key_size);
entry->val = elt;
atomic64_inc(&map->hits);
return entry->val;
}
}
idx++;
}
return NULL;
}
/**
* tracing_map_insert - Insert key and/or retrieve val from a tracing_map
* @map: The tracing_map to insert into
* @key: The key to insert
*
* Inserts a key into a tracing_map and creates and returns a new
* tracing_map_elt for it, or if the key has already been inserted by
* a previous call, returns the tracing_map_elt already associated
* with it. When the map was created, the number of elements to be
* allocated for the map was specified (internally maintained as
* 'max_elts' in struct tracing_map), and that number of
* tracing_map_elts was created by tracing_map_init(). This is the
* pre-allocated pool of tracing_map_elts that tracing_map_insert()
* will allocate from when adding new keys. Once that pool is
* exhausted, tracing_map_insert() is useless and will return NULL to
* signal that state. There are two user-visible tracing_map
* variables, 'hits' and 'drops', which are updated by this function.
* Every time an element is either successfully inserted or retrieved,
* the 'hits' value is incrememented. Every time an element insertion
* fails, the 'drops' value is incremented.
*
* This is a lock-free tracing map insertion function implementing a
* modified form of Cliff Click's basic insertion algorithm. It
* requires the table size be a power of two. To prevent any
* possibility of an infinite loop we always make the internal table
* size double the size of the requested table size (max_elts * 2).
* Likewise, we never reuse a slot or resize or delete elements - when
* we've reached max_elts entries, we simply return NULL once we've
* run out of entries. Readers can at any point in time traverse the
* tracing map and safely access the key/val pairs.
*
* Return: the tracing_map_elt pointer val associated with the key.
* If this was a newly inserted key, the val will be a newly allocated
* and associated tracing_map_elt pointer val. If the key wasn't
* found and the pool of tracing_map_elts has been exhausted, NULL is
* returned and no further insertions will succeed.
*/
struct tracing_map_elt *tracing_map_insert(struct tracing_map *map, void *key)
{
return __tracing_map_insert(map, key, false);
}
/**
* tracing_map_lookup - Retrieve val from a tracing_map
* @map: The tracing_map to perform the lookup on
* @key: The key to look up
*
* Looks up key in tracing_map and if found returns the matching
* tracing_map_elt. This is a lock-free lookup; see
* tracing_map_insert() for details on tracing_map and how it works.
* Every time an element is retrieved, the 'hits' value is
* incrememented. There is one user-visible tracing_map variable,
* 'hits', which is updated by this function. Every time an element
* is successfully retrieved, the 'hits' value is incrememented. The
* 'drops' value is never updated by this function.
*
* Return: the tracing_map_elt pointer val associated with the key.
* If the key wasn't found, NULL is returned.
*/
struct tracing_map_elt *tracing_map_lookup(struct tracing_map *map, void *key)
{
return __tracing_map_insert(map, key, true);
}
/**
* tracing_map_destroy - Destroy a tracing_map
* @map: The tracing_map to destroy
*
* Frees a tracing_map along with its associated array of
* tracing_map_elts.
*
* Callers should make sure there are no readers or writers actively
* reading or inserting into the map before calling this.
*/
void tracing_map_destroy(struct tracing_map *map)
{
if (!map)
return;
tracing_map_free_elts(map);
tracing_map_array_free(map->map);
kfree(map);
}
/**
* tracing_map_clear - Clear a tracing_map
* @map: The tracing_map to clear
*
* Resets the tracing map to a cleared or initial state. The
* tracing_map_elts are all cleared, and the array of struct
* tracing_map_entry is reset to an initialized state.
*
* Callers should make sure there are no writers actively inserting
* into the map before calling this.
*/
void tracing_map_clear(struct tracing_map *map)
{
unsigned int i;
atomic_set(&map->next_elt, -1);
atomic64_set(&map->hits, 0);
atomic64_set(&map->drops, 0);
tracing_map_array_clear(map->map);
for (i = 0; i < map->max_elts; i++)
tracing_map_elt_clear(*(TRACING_MAP_ELT(map->elts, i)));
}
static void set_sort_key(struct tracing_map *map,
struct tracing_map_sort_key *sort_key)
{
map->sort_key = *sort_key;
}
/**
* tracing_map_create - Create a lock-free map and element pool
* @map_bits: The size of the map (2 ** map_bits)
* @key_size: The size of the key for the map in bytes
* @ops: Optional client-defined tracing_map_ops instance
* @private_data: Client data associated with the map
*
* Creates and sets up a map to contain 2 ** map_bits number of
* elements (internally maintained as 'max_elts' in struct
* tracing_map). Before using, map fields should be added to the map
* with tracing_map_add_sum_field() and tracing_map_add_key_field().
* tracing_map_init() should then be called to allocate the array of
* tracing_map_elts, in order to avoid allocating anything in the map
* insertion path. The user-specified map size reflects the maximum
* number of elements that can be contained in the table requested by
* the user - internally we double that in order to keep the table
* sparse and keep collisions manageable.
*
* A tracing_map is a special-purpose map designed to aggregate or
* 'sum' one or more values associated with a specific object of type
* tracing_map_elt, which is attached by the map to a given key.
*
* tracing_map_create() sets up the map itself, and provides
* operations for inserting tracing_map_elts, but doesn't allocate the
* tracing_map_elts themselves, or provide a means for describing the
* keys or sums associated with the tracing_map_elts. All
* tracing_map_elts for a given map have the same set of sums and
* keys, which are defined by the client using the functions
* tracing_map_add_key_field() and tracing_map_add_sum_field(). Once
* the fields are defined, the pool of elements allocated for the map
* can be created, which occurs when the client code calls
* tracing_map_init().
*
* When tracing_map_init() returns, tracing_map_elt elements can be
* inserted into the map using tracing_map_insert(). When called,
* tracing_map_insert() grabs a free tracing_map_elt from the pool, or
* finds an existing match in the map and in either case returns it.
* The client can then use tracing_map_update_sum() and
* tracing_map_read_sum() to update or read a given sum field for the
* tracing_map_elt.
*
* The client can at any point retrieve and traverse the current set
* of inserted tracing_map_elts in a tracing_map, via
* tracing_map_sort_entries(). Sorting can be done on any field,
* including keys.
*
* See tracing_map.h for a description of tracing_map_ops.
*
* Return: the tracing_map pointer if successful, ERR_PTR if not.
*/
struct tracing_map *tracing_map_create(unsigned int map_bits,
unsigned int key_size,
const struct tracing_map_ops *ops,
void *private_data)
{
struct tracing_map *map;
unsigned int i;
if (map_bits < TRACING_MAP_BITS_MIN ||
map_bits > TRACING_MAP_BITS_MAX)
return ERR_PTR(-EINVAL);
map = kzalloc(sizeof(*map), GFP_KERNEL);
if (!map)
return ERR_PTR(-ENOMEM);
map->map_bits = map_bits;
map->max_elts = (1 << map_bits);
atomic_set(&map->next_elt, -1);
map->map_size = (1 << (map_bits + 1));
map->ops = ops;
map->private_data = private_data;
map->map = tracing_map_array_alloc(map->map_size,
sizeof(struct tracing_map_entry));
if (!map->map)
goto free;
map->key_size = key_size;
for (i = 0; i < TRACING_MAP_KEYS_MAX; i++)
map->key_idx[i] = -1;
out:
return map;
free:
tracing_map_destroy(map);
map = ERR_PTR(-ENOMEM);
goto out;
}
/**
* tracing_map_init - Allocate and clear a map's tracing_map_elts
* @map: The tracing_map to initialize
*
* Allocates a clears a pool of tracing_map_elts equal to the
* user-specified size of 2 ** map_bits (internally maintained as
* 'max_elts' in struct tracing_map). Before using, the map fields
* should be added to the map with tracing_map_add_sum_field() and
* tracing_map_add_key_field(). tracing_map_init() should then be
* called to allocate the array of tracing_map_elts, in order to avoid
* allocating anything in the map insertion path. The user-specified
* map size reflects the max number of elements requested by the user
* - internally we double that in order to keep the table sparse and
* keep collisions manageable.
*
* See tracing_map.h for a description of tracing_map_ops.
*
* Return: the tracing_map pointer if successful, ERR_PTR if not.
*/
int tracing_map_init(struct tracing_map *map)
{
int err;
if (map->n_fields < 2)
return -EINVAL; /* need at least 1 key and 1 val */
err = tracing_map_alloc_elts(map);
if (err)
return err;
tracing_map_clear(map);
return err;
}
static int cmp_entries_dup(const struct tracing_map_sort_entry **a,
const struct tracing_map_sort_entry **b)
{
int ret = 0;
if (memcmp((*a)->key, (*b)->key, (*a)->elt->map->key_size))
ret = 1;
return ret;
}
static int cmp_entries_sum(const struct tracing_map_sort_entry **a,
const struct tracing_map_sort_entry **b)
{
const struct tracing_map_elt *elt_a, *elt_b;
struct tracing_map_sort_key *sort_key;
struct tracing_map_field *field;
tracing_map_cmp_fn_t cmp_fn;
void *val_a, *val_b;
int ret = 0;
elt_a = (*a)->elt;
elt_b = (*b)->elt;
sort_key = &elt_a->map->sort_key;
field = &elt_a->fields[sort_key->field_idx];
cmp_fn = field->cmp_fn;
val_a = &elt_a->fields[sort_key->field_idx].sum;
val_b = &elt_b->fields[sort_key->field_idx].sum;
ret = cmp_fn(val_a, val_b);
if (sort_key->descending)
ret = -ret;
return ret;
}
static int cmp_entries_key(const struct tracing_map_sort_entry **a,
const struct tracing_map_sort_entry **b)
{
const struct tracing_map_elt *elt_a, *elt_b;
struct tracing_map_sort_key *sort_key;
struct tracing_map_field *field;
tracing_map_cmp_fn_t cmp_fn;
void *val_a, *val_b;
int ret = 0;
elt_a = (*a)->elt;
elt_b = (*b)->elt;
sort_key = &elt_a->map->sort_key;
field = &elt_a->fields[sort_key->field_idx];
cmp_fn = field->cmp_fn;
val_a = elt_a->key + field->offset;
val_b = elt_b->key + field->offset;
ret = cmp_fn(val_a, val_b);
if (sort_key->descending)
ret = -ret;
return ret;
}
static void destroy_sort_entry(struct tracing_map_sort_entry *entry)
{
if (!entry)
return;
if (entry->elt_copied)
tracing_map_elt_free(entry->elt);
kfree(entry);
}
/**
* tracing_map_destroy_sort_entries - Destroy an array of sort entries
* @entries: The entries to destroy
* @n_entries: The number of entries in the array
*
* Destroy the elements returned by a tracing_map_sort_entries() call.
*/
void tracing_map_destroy_sort_entries(struct tracing_map_sort_entry **entries,
unsigned int n_entries)
{
unsigned int i;
for (i = 0; i < n_entries; i++)
destroy_sort_entry(entries[i]);
vfree(entries);
}
static struct tracing_map_sort_entry *
create_sort_entry(void *key, struct tracing_map_elt *elt)
{
struct tracing_map_sort_entry *sort_entry;
sort_entry = kzalloc(sizeof(*sort_entry), GFP_KERNEL);
if (!sort_entry)
return NULL;
sort_entry->key = key;
sort_entry->elt = elt;
return sort_entry;
}
static struct tracing_map_elt *copy_elt(struct tracing_map_elt *elt)
{
struct tracing_map_elt *dup_elt;
unsigned int i;
dup_elt = tracing_map_elt_alloc(elt->map);
if (IS_ERR(dup_elt))
return NULL;
if (elt->map->ops && elt->map->ops->elt_copy)
elt->map->ops->elt_copy(dup_elt, elt);
dup_elt->private_data = elt->private_data;
memcpy(dup_elt->key, elt->key, elt->map->key_size);
for (i = 0; i < elt->map->n_fields; i++) {
atomic64_set(&dup_elt->fields[i].sum,
atomic64_read(&elt->fields[i].sum));
dup_elt->fields[i].cmp_fn = elt->fields[i].cmp_fn;
}
return dup_elt;
}
static int merge_dup(struct tracing_map_sort_entry **sort_entries,
unsigned int target, unsigned int dup)
{
struct tracing_map_elt *target_elt, *elt;
bool first_dup = (target - dup) == 1;
int i;
if (first_dup) {
elt = sort_entries[target]->elt;
target_elt = copy_elt(elt);
if (!target_elt)
return -ENOMEM;
sort_entries[target]->elt = target_elt;
sort_entries[target]->elt_copied = true;
} else
target_elt = sort_entries[target]->elt;
elt = sort_entries[dup]->elt;
for (i = 0; i < elt->map->n_fields; i++)
atomic64_add(atomic64_read(&elt->fields[i].sum),
&target_elt->fields[i].sum);
sort_entries[dup]->dup = true;
return 0;
}
static int merge_dups(struct tracing_map_sort_entry **sort_entries,
int n_entries, unsigned int key_size)
{
unsigned int dups = 0, total_dups = 0;
int err, i, j;
void *key;
if (n_entries < 2)
return total_dups;
sort(sort_entries, n_entries, sizeof(struct tracing_map_sort_entry *),
(int (*)(const void *, const void *))cmp_entries_dup, NULL);
key = sort_entries[0]->key;
for (i = 1; i < n_entries; i++) {
if (!memcmp(sort_entries[i]->key, key, key_size)) {
dups++; total_dups++;
err = merge_dup(sort_entries, i - dups, i);
if (err)
return err;
continue;
}
key = sort_entries[i]->key;
dups = 0;
}
if (!total_dups)
return total_dups;
for (i = 0, j = 0; i < n_entries; i++) {
if (!sort_entries[i]->dup) {
sort_entries[j] = sort_entries[i];
if (j++ != i)
sort_entries[i] = NULL;
} else {
destroy_sort_entry(sort_entries[i]);
sort_entries[i] = NULL;
}
}
return total_dups;
}
static bool is_key(struct tracing_map *map, unsigned int field_idx)
{
unsigned int i;
for (i = 0; i < map->n_keys; i++)
if (map->key_idx[i] == field_idx)
return true;
return false;
}
static void sort_secondary(struct tracing_map *map,
const struct tracing_map_sort_entry **entries,
unsigned int n_entries,
struct tracing_map_sort_key *primary_key,
struct tracing_map_sort_key *secondary_key)
{
int (*primary_fn)(const struct tracing_map_sort_entry **,
const struct tracing_map_sort_entry **);
int (*secondary_fn)(const struct tracing_map_sort_entry **,
const struct tracing_map_sort_entry **);
unsigned i, start = 0, n_sub = 1;
if (is_key(map, primary_key->field_idx))
primary_fn = cmp_entries_key;
else
primary_fn = cmp_entries_sum;
if (is_key(map, secondary_key->field_idx))
secondary_fn = cmp_entries_key;
else
secondary_fn = cmp_entries_sum;
for (i = 0; i < n_entries - 1; i++) {
const struct tracing_map_sort_entry **a = &entries[i];
const struct tracing_map_sort_entry **b = &entries[i + 1];
if (primary_fn(a, b) == 0) {
n_sub++;
if (i < n_entries - 2)
continue;
}
if (n_sub < 2) {
start = i + 1;
n_sub = 1;
continue;
}
set_sort_key(map, secondary_key);
sort(&entries[start], n_sub,
sizeof(struct tracing_map_sort_entry *),
(int (*)(const void *, const void *))secondary_fn, NULL);
set_sort_key(map, primary_key);
start = i + 1;
n_sub = 1;
}
}
/**
* tracing_map_sort_entries - Sort the current set of tracing_map_elts in a map
* @map: The tracing_map
* @sort_key: The sort key to use for sorting
* @sort_entries: outval: pointer to allocated and sorted array of entries
*
* tracing_map_sort_entries() sorts the current set of entries in the
* map and returns the list of tracing_map_sort_entries containing
* them to the client in the sort_entries param. The client can
* access the struct tracing_map_elt element of interest directly as
* the 'elt' field of a returned struct tracing_map_sort_entry object.
*
* The sort_key has only two fields: idx and descending. 'idx' refers
* to the index of the field added via tracing_map_add_sum_field() or
* tracing_map_add_key_field() when the tracing_map was initialized.
* 'descending' is a flag that if set reverses the sort order, which
* by default is ascending.
*
* The client should not hold on to the returned array but should use
* it and call tracing_map_destroy_sort_entries() when done.
*
* Return: the number of sort_entries in the struct tracing_map_sort_entry
* array, negative on error
*/
int tracing_map_sort_entries(struct tracing_map *map,
struct tracing_map_sort_key *sort_keys,
unsigned int n_sort_keys,
struct tracing_map_sort_entry ***sort_entries)
{
int (*cmp_entries_fn)(const struct tracing_map_sort_entry **,
const struct tracing_map_sort_entry **);
struct tracing_map_sort_entry *sort_entry, **entries;
int i, n_entries, ret;
entries = vmalloc(map->max_elts * sizeof(sort_entry));
if (!entries)
return -ENOMEM;
for (i = 0, n_entries = 0; i < map->map_size; i++) {
struct tracing_map_entry *entry;
entry = TRACING_MAP_ENTRY(map->map, i);
if (!entry->key || !entry->val)
continue;
entries[n_entries] = create_sort_entry(entry->val->key,
entry->val);
if (!entries[n_entries++]) {
ret = -ENOMEM;
goto free;
}
}
if (n_entries == 0) {
ret = 0;
goto free;
}
if (n_entries == 1) {
*sort_entries = entries;
return 1;
}
ret = merge_dups(entries, n_entries, map->key_size);
if (ret < 0)
goto free;
n_entries -= ret;
if (is_key(map, sort_keys[0].field_idx))
cmp_entries_fn = cmp_entries_key;
else
cmp_entries_fn = cmp_entries_sum;
set_sort_key(map, &sort_keys[0]);
sort(entries, n_entries, sizeof(struct tracing_map_sort_entry *),
(int (*)(const void *, const void *))cmp_entries_fn, NULL);
if (n_sort_keys > 1)
sort_secondary(map,
(const struct tracing_map_sort_entry **)entries,
n_entries,
&sort_keys[0],
&sort_keys[1]);
*sort_entries = entries;
return n_entries;
free:
tracing_map_destroy_sort_entries(entries, n_entries);
return ret;
}
kernel/trace/tracing_map.h 0 → 100644
View file @ 2600a46e
#ifndef __TRACING_MAP_H
#define __TRACING_MAP_H
#define TRACING_MAP_BITS_DEFAULT 11
#define TRACING_MAP_BITS_MAX 17
#define TRACING_MAP_BITS_MIN 7
#define TRACING_MAP_KEYS_MAX 2
#define TRACING_MAP_VALS_MAX 3
#define TRACING_MAP_FIELDS_MAX (TRACING_MAP_KEYS_MAX + \
TRACING_MAP_VALS_MAX)
#define TRACING_MAP_SORT_KEYS_MAX 2
typedef int (*tracing_map_cmp_fn_t) (void *val_a, void *val_b);
/*
* This is an overview of the tracing_map data structures and how they
* relate to the tracing_map API. The details of the algorithms
* aren't discussed here - this is just a general overview of the data
* structures and how they interact with the API.
*
* The central data structure of the tracing_map is an initially
* zeroed array of struct tracing_map_entry (stored in the map field
* of struct tracing_map). tracing_map_entry is a very simple data
* structure containing only two fields: a 32-bit unsigned 'key'
* variable and a pointer named 'val'. This array of struct
* tracing_map_entry is essentially a hash table which will be
* modified by a single function, tracing_map_insert(), but which can
* be traversed and read by a user at any time (though the user does
* this indirectly via an array of tracing_map_sort_entry - see the
* explanation of that data structure in the discussion of the
* sorting-related data structures below).
*
* The central function of the tracing_map API is
* tracing_map_insert(). tracing_map_insert() hashes the
* arbitrarily-sized key passed into it into a 32-bit unsigned key.
* It then uses this key, truncated to the array size, as an index
* into the array of tracing_map_entries. If the value of the 'key'
* field of the tracing_map_entry found at that location is 0, then
* that entry is considered to be free and can be claimed, by
* replacing the 0 in the 'key' field of the tracing_map_entry with
* the new 32-bit hashed key. Once claimed, that tracing_map_entry's
* 'val' field is then used to store a unique element which will be
* forever associated with that 32-bit hashed key in the
* tracing_map_entry.
*
* That unique element now in the tracing_map_entry's 'val' field is
* an instance of tracing_map_elt, where 'elt' in the latter part of
* that variable name is short for 'element'. The purpose of a
* tracing_map_elt is to hold values specific to the particular
* 32-bit hashed key it's assocated with. Things such as the unique
* set of aggregated sums associated with the 32-bit hashed key, along
* with a copy of the full key associated with the entry, and which
* was used to produce the 32-bit hashed key.
*
* When tracing_map_create() is called to create the tracing map, the
* user specifies (indirectly via the map_bits param, the details are
* unimportant for this discussion) the maximum number of elements
* that the map can hold (stored in the max_elts field of struct
* tracing_map). This is the maximum possible number of
* tracing_map_entries in the tracing_map_entry array which can be
* 'claimed' as described in the above discussion, and therefore is
* also the maximum number of tracing_map_elts that can be associated
* with the tracing_map_entry array in the tracing_map. Because of
* the way the insertion algorithm works, the size of the allocated
* tracing_map_entry array is always twice the maximum number of
* elements (2 * max_elts). This value is stored in the map_size
* field of struct tracing_map.
*
* Because tracing_map_insert() needs to work from any context,
* including from within the memory allocation functions themselves,
* both the tracing_map_entry array and a pool of max_elts
* tracing_map_elts are pre-allocated before any call is made to
* tracing_map_insert().
*
* The tracing_map_entry array is allocated as a single block by
* tracing_map_create().
*
* Because the tracing_map_elts are much larger objects and can't
* generally be allocated together as a single large array without
* failure, they're allocated individually, by tracing_map_init().
*
* The pool of tracing_map_elts are allocated by tracing_map_init()
* rather than by tracing_map_create() because at the time
* tracing_map_create() is called, there isn't enough information to
* create the tracing_map_elts. Specifically,the user first needs to
* tell the tracing_map implementation how many fields the
* tracing_map_elts contain, and which types of fields they are (key
* or sum). The user does this via the tracing_map_add_sum_field()
* and tracing_map_add_key_field() functions, following which the user
* calls tracing_map_init() to finish up the tracing map setup. The
* array holding the pointers which make up the pre-allocated pool of
* tracing_map_elts is allocated as a single block and is stored in
* the elts field of struct tracing_map.
*
* There is also a set of structures used for sorting that might
* benefit from some minimal explanation.
*
* struct tracing_map_sort_key is used to drive the sort at any given
* time. By 'any given time' we mean that a different
* tracing_map_sort_key will be used at different times depending on
* whether the sort currently being performed is a primary or a
* secondary sort.
*
* The sort key is very simple, consisting of the field index of the
* tracing_map_elt field to sort on (which the user saved when adding
* the field), and whether the sort should be done in an ascending or
* descending order.
*
* For the convenience of the sorting code, a tracing_map_sort_entry
* is created for each tracing_map_elt, again individually allocated
* to avoid failures that might be expected if allocated as a single
* large array of struct tracing_map_sort_entry.
* tracing_map_sort_entry instances are the objects expected by the
* various internal sorting functions, and are also what the user
* ultimately receives after calling tracing_map_sort_entries().
* Because it doesn't make sense for users to access an unordered and
* sparsely populated tracing_map directly, the
* tracing_map_sort_entries() function is provided so that users can
* retrieve a sorted list of all existing elements. In addition to
* the associated tracing_map_elt 'elt' field contained within the
* tracing_map_sort_entry, which is the object of interest to the
* user, tracing_map_sort_entry objects contain a number of additional
* fields which are used for caching and internal purposes and can
* safely be ignored.
*/
struct tracing_map_field {
tracing_map_cmp_fn_t cmp_fn;
union {
atomic64_t sum;
unsigned int offset;
};
};
struct tracing_map_elt {
struct tracing_map *map;
struct tracing_map_field *fields;
void *key;
void *private_data;
};
struct tracing_map_entry {
u32 key;
struct tracing_map_elt *val;
};
struct tracing_map_sort_key {
unsigned int field_idx;
bool descending;
};
struct tracing_map_sort_entry {
void *key;
struct tracing_map_elt *elt;
bool elt_copied;
bool dup;
};
struct tracing_map_array {
unsigned int entries_per_page;
unsigned int entry_size_shift;
unsigned int entry_shift;
unsigned int entry_mask;
unsigned int n_pages;
void **pages;
};
#define TRACING_MAP_ARRAY_ELT(array, idx) \
(array->pages[idx >> array->entry_shift] + \
((idx & array->entry_mask) << array->entry_size_shift))
#define TRACING_MAP_ENTRY(array, idx) \
((struct tracing_map_entry *)TRACING_MAP_ARRAY_ELT(array, idx))
#define TRACING_MAP_ELT(array, idx) \
((struct tracing_map_elt **)TRACING_MAP_ARRAY_ELT(array, idx))
struct tracing_map {
unsigned int key_size;
unsigned int map_bits;
unsigned int map_size;
unsigned int max_elts;
atomic_t next_elt;
struct tracing_map_array *elts;
struct tracing_map_array *map;
const struct tracing_map_ops *ops;
void *private_data;
struct tracing_map_field fields[TRACING_MAP_FIELDS_MAX];
unsigned int n_fields;
int key_idx[TRACING_MAP_KEYS_MAX];
unsigned int n_keys;
struct tracing_map_sort_key sort_key;
atomic64_t hits;
atomic64_t drops;
};
/**
* struct tracing_map_ops - callbacks for tracing_map
*
* The methods in this structure define callback functions for various
* operations on a tracing_map or objects related to a tracing_map.
*
* For a detailed description of tracing_map_elt objects please see
* the overview of tracing_map data structures at the beginning of
* this file.
*
* All the methods below are optional.
*
* @elt_alloc: When a tracing_map_elt is allocated, this function, if
* defined, will be called and gives clients the opportunity to
* allocate additional data and attach it to the element
* (tracing_map_elt->private_data is meant for that purpose).
* Element allocation occurs before tracing begins, when the
* tracing_map_init() call is made by client code.
*
* @elt_copy: At certain points in the lifetime of an element, it may
* need to be copied. The copy should include a copy of the
* client-allocated data, which can be copied into the 'to'
* element from the 'from' element.
*
* @elt_free: When a tracing_map_elt is freed, this function is called
* and allows client-allocated per-element data to be freed.
*
* @elt_clear: This callback allows per-element client-defined data to
* be cleared, if applicable.
*
* @elt_init: This callback allows per-element client-defined data to
* be initialized when used i.e. when the element is actually
* claimed by tracing_map_insert() in the context of the map
* insertion.
*/
struct tracing_map_ops {
int (*elt_alloc)(struct tracing_map_elt *elt);
void (*elt_copy)(struct tracing_map_elt *to,
struct tracing_map_elt *from);
void (*elt_free)(struct tracing_map_elt *elt);
void (*elt_clear)(struct tracing_map_elt *elt);
void (*elt_init)(struct tracing_map_elt *elt);
};
extern struct tracing_map *
tracing_map_create(unsigned int map_bits,
unsigned int key_size,
const struct tracing_map_ops *ops,
void *private_data);
extern int tracing_map_init(struct tracing_map *map);
extern int tracing_map_add_sum_field(struct tracing_map *map);
extern int tracing_map_add_key_field(struct tracing_map *map,
unsigned int offset,
tracing_map_cmp_fn_t cmp_fn);
extern void tracing_map_destroy(struct tracing_map *map);
extern void tracing_map_clear(struct tracing_map *map);
extern struct tracing_map_elt *
tracing_map_insert(struct tracing_map *map, void *key);
extern struct tracing_map_elt *
tracing_map_lookup(struct tracing_map *map, void *key);
extern tracing_map_cmp_fn_t tracing_map_cmp_num(int field_size,
int field_is_signed);
extern int tracing_map_cmp_string(void *val_a, void *val_b);
extern int tracing_map_cmp_none(void *val_a, void *val_b);
extern void tracing_map_update_sum(struct tracing_map_elt *elt,
unsigned int i, u64 n);
extern u64 tracing_map_read_sum(struct tracing_map_elt *elt, unsigned int i);
extern void tracing_map_set_field_descr(struct tracing_map *map,
unsigned int i,
unsigned int key_offset,
tracing_map_cmp_fn_t cmp_fn);
extern int
tracing_map_sort_entries(struct tracing_map *map,
struct tracing_map_sort_key *sort_keys,
unsigned int n_sort_keys,
struct tracing_map_sort_entry ***sort_entries);
extern void
tracing_map_destroy_sort_entries(struct tracing_map_sort_entry **entries,
unsigned int n_entries);
#endif /* __TRACING_MAP_H */
tools/testing/selftests/ftrace/test.d/functions
View file @ 2600a46e
......@@ -14,3 +14,12 @@ enable_tracing() { # start trace recording
reset_tracer() { # reset the current tracer
echo nop > current_tracer
}
reset_trigger() { # reset all current setting triggers
grep -v ^# events/*/*/trigger |
while read line; do
cmd=`echo $line | cut -f2- -d: | cut -f1 -d" "`
echo "!$cmd" > `echo $line | cut -f1 -d:`
done
}
tools/testing/selftests/ftrace/test.d/trigger/trigger-eventonoff.tc 0 → 100644
View file @ 2600a46e
#!/bin/sh
# description: event trigger - test event enable/disable trigger
do_reset() {
reset_trigger
echo > set_event
clear_trace
}
fail() { #msg
do_reset
echo $1
exit $FAIL
}
if [ ! -f set_event -o ! -d events/sched ]; then
echo "event tracing is not supported"
exit_unsupported
fi
if [ ! -f events/sched/sched_process_fork/trigger ]; then
echo "event trigger is not supported"
exit_unsupported
fi
reset_tracer
do_reset
FEATURE=`grep enable_event events/sched/sched_process_fork/trigger`
if [ -z "$FEATURE" ]; then
echo "event enable/disable trigger is not supported"
exit_unsupported
fi
echo "Test enable_event trigger"
echo 0 > events/sched/sched_switch/enable
echo 'enable_event:sched:sched_switch' > events/sched/sched_process_fork/trigger
( echo "forked")
if [ `cat events/sched/sched_switch/enable` != '1*' ]; then
fail "enable_event trigger on sched_process_fork did not work"
fi
reset_trigger
echo "Test disable_event trigger"
echo 1 > events/sched/sched_switch/enable
echo 'disable_event:sched:sched_switch' > events/sched/sched_process_fork/trigger
( echo "forked")
if [ `cat events/sched/sched_switch/enable` != '0*' ]; then
fail "disable_event trigger on sched_process_fork did not work"
fi
reset_trigger
echo "Test semantic error for event enable/disable trigger"
! echo 'enable_event:nogroup:noevent' > events/sched/sched_process_fork/trigger
! echo 'disable_event+1' > events/sched/sched_process_fork/trigger
echo 'enable_event:sched:sched_switch' > events/sched/sched_process_fork/trigger
! echo 'enable_event:sched:sched_switch' > events/sched/sched_process_fork/trigger
! echo 'disable_event:sched:sched_switch' > events/sched/sched_process_fork/trigger
do_reset
exit 0
tools/testing/selftests/ftrace/test.d/trigger/trigger-filter.tc 0 → 100644
View file @ 2600a46e
#!/bin/sh
# description: event trigger - test trigger filter
do_reset() {
reset_trigger
echo > set_event
clear_trace
}
fail() { #msg
do_reset
echo $1
exit $FAIL
}
if [ ! -f set_event -o ! -d events/sched ]; then
echo "event tracing is not supported"
exit_unsupported
fi
if [ ! -f events/sched/sched_process_fork/trigger ]; then
echo "event trigger is not supported"
exit_unsupported
fi
reset_tracer
do_reset
echo "Test trigger filter"
echo 1 > tracing_on
echo 'traceoff if child_pid == 0' > events/sched/sched_process_fork/trigger
( echo "forked")
if [ `cat tracing_on` -ne 1 ]; then
fail "traceoff trigger on sched_process_fork did not work"
fi
reset_trigger
echo "Test semantic error for trigger filter"
! echo 'traceoff if a' > events/sched/sched_process_fork/trigger
! echo 'traceoff if common_pid=0' > events/sched/sched_process_fork/trigger
! echo 'traceoff if common_pid==b' > events/sched/sched_process_fork/trigger
echo 'traceoff if common_pid == 0' > events/sched/sched_process_fork/trigger
echo '!traceoff' > events/sched/sched_process_fork/trigger
! echo 'traceoff if common_pid == child_pid' > events/sched/sched_process_fork/trigger
echo 'traceoff if common_pid <= 0' > events/sched/sched_process_fork/trigger
echo '!traceoff' > events/sched/sched_process_fork/trigger
echo 'traceoff if common_pid >= 0' > events/sched/sched_process_fork/trigger
echo '!traceoff' > events/sched/sched_process_fork/trigger
echo 'traceoff if parent_pid >= 0 && child_pid >= 0' > events/sched/sched_process_fork/trigger
echo '!traceoff' > events/sched/sched_process_fork/trigger
echo 'traceoff if parent_pid >= 0 || child_pid >= 0' > events/sched/sched_process_fork/trigger
echo '!traceoff' > events/sched/sched_process_fork/trigger
do_reset
exit 0
tools/testing/selftests/ftrace/test.d/trigger/trigger-hist-mod.tc 0 → 100644
View file @ 2600a46e
#!/bin/sh
# description: event trigger - test histogram modifiers
do_reset() {
reset_trigger
echo > set_event
clear_trace
}
fail() { #msg
do_reset
echo $1
exit $FAIL
}
if [ ! -f set_event -o ! -d events/sched ]; then
echo "event tracing is not supported"
exit_unsupported
fi
if [ ! -f events/sched/sched_process_fork/trigger ]; then
echo "event trigger is not supported"
exit_unsupported
fi
reset_tracer
do_reset
FEATURE=`grep hist events/sched/sched_process_fork/trigger`
if [ -z "$FEATURE" ]; then
echo "hist trigger is not supported"
exit_unsupported
fi
echo "Test histogram with execname modifier"
echo 'hist:keys=common_pid.execname' > events/sched/sched_process_fork/trigger
for i in `seq 1 10` ; do ( echo "forked" > /dev/null); done
COMM=`cat /proc/$$/comm`
grep "common_pid: $COMM" events/sched/sched_process_fork/hist > /dev/null || \
fail "execname modifier on sched_process_fork did not work"
reset_trigger
echo "Test histogram with hex modifier"
echo 'hist:keys=parent_pid.hex' > events/sched/sched_process_fork/trigger
for i in `seq 1 10` ; do ( echo "forked" > /dev/null); done
# Note that $$ is the parent pid. $PID is current PID.
HEX=`printf %x $PID`
grep "parent_pid: $HEX" events/sched/sched_process_fork/hist > /dev/null || \
fail "hex modifier on sched_process_fork did not work"
reset_trigger
echo "Test histogram with syscall modifier"
echo 'hist:keys=id.syscall' > events/raw_syscalls/sys_exit/trigger
for i in `seq 1 10` ; do ( echo "forked" > /dev/null); done
grep "id: sys_" events/raw_syscalls/sys_exit/hist > /dev/null || \
fail "syscall modifier on raw_syscalls/sys_exit did not work"
reset_trigger
echo "Test histgram with log2 modifier"
echo 'hist:keys=bytes_req.log2' > events/kmem/kmalloc/trigger
for i in `seq 1 10` ; do ( echo "forked" > /dev/null); done
grep 'bytes_req: ~ 2^[0-9]*' events/kmem/kmalloc/hist > /dev/null || \
fail "log2 modifier on kmem/kmalloc did not work"
do_reset
exit 0
tools/testing/selftests/ftrace/test.d/trigger/trigger-hist.tc 0 → 100644
View file @ 2600a46e
#!/bin/sh
# description: event trigger - test histogram trigger
do_reset() {
reset_trigger
echo > set_event
clear_trace
}
fail() { #msg
do_reset
echo $1
exit $FAIL
}
if [ ! -f set_event -o ! -d events/sched ]; then
echo "event tracing is not supported"
exit_unsupported
fi
if [ ! -f events/sched/sched_process_fork/trigger ]; then
echo "event trigger is not supported"
exit_unsupported
fi
reset_tracer
do_reset
FEATURE=`grep hist events/sched/sched_process_fork/trigger`
if [ -z "$FEATURE" ]; then
echo "hist trigger is not supported"
exit_unsupported
fi
echo "Test histogram basic tigger"
echo 'hist:keys=parent_pid:vals=child_pid' > events/sched/sched_process_fork/trigger
for i in `seq 1 10` ; do ( echo "forked" > /dev/null); done
grep parent_pid events/sched/sched_process_fork/hist > /dev/null || \
fail "hist trigger on sched_process_fork did not work"
grep child events/sched/sched_process_fork/hist > /dev/null || \
fail "hist trigger on sched_process_fork did not work"
reset_trigger
echo "Test histogram with compound keys"
echo 'hist:keys=parent_pid,child_pid' > events/sched/sched_process_fork/trigger
for i in `seq 1 10` ; do ( echo "forked" > /dev/null); done
grep '^{ parent_pid:.*, child_pid:.*}' events/sched/sched_process_fork/hist > /dev/null || \
fail "compound keys on sched_process_fork did not work"
reset_trigger
echo "Test histogram with string key"
echo 'hist:keys=parent_comm' > events/sched/sched_process_fork/trigger
for i in `seq 1 10` ; do ( echo "forked" > /dev/null); done
COMM=`cat /proc/$$/comm`
grep "parent_comm: $COMM" events/sched/sched_process_fork/hist > /dev/null || \
fail "string key on sched_process_fork did not work"
reset_trigger
echo "Test histogram with sort key"
echo 'hist:keys=parent_pid,child_pid:sort=child_pid.ascending' > events/sched/sched_process_fork/trigger
for i in `seq 1 10` ; do ( echo "forked" > /dev/null); done
check_inc() {
while [ $# -gt 1 ]; do
[ $1 -gt $2 ] && return 1
shift 1
done
return 0
}
check_inc `grep -o "child_pid:[[:space:]]*[[:digit:]]*" \
events/sched/sched_process_fork/hist | cut -d: -f2 ` ||
fail "sort param on sched_process_fork did not work"
do_reset
exit 0
tools/testing/selftests/ftrace/test.d/trigger/trigger-multihist.tc 0 → 100644
View file @ 2600a46e
#!/bin/sh
# description: event trigger - test multiple histogram triggers
do_reset() {
reset_trigger
echo > set_event
clear_trace
}
fail() { #msg
do_reset
echo $1
exit $FAIL
}
if [ ! -f set_event -o ! -d events/sched ]; then
echo "event tracing is not supported"
exit_unsupported
fi
if [ ! -f events/sched/sched_process_fork/trigger ]; then
echo "event trigger is not supported"
exit_unsupported
fi
reset_tracer
do_reset
FEATURE=`grep hist events/sched/sched_process_fork/trigger`
if [ -z "$FEATURE" ]; then
echo "hist trigger is not supported"
exit_unsupported
fi
reset_trigger
echo "Test histogram multiple tiggers"
echo 'hist:keys=parent_pid:vals=child_pid' > events/sched/sched_process_fork/trigger
echo 'hist:keys=parent_comm:vals=child_pid' >> events/sched/sched_process_fork/trigger
for i in `seq 1 10` ; do ( echo "forked" > /dev/null); done
grep parent_pid events/sched/sched_process_fork/hist > /dev/null || \
fail "hist trigger on sched_process_fork did not work"
grep child events/sched/sched_process_fork/hist > /dev/null || \
fail "hist trigger on sched_process_fork did not work"
COMM=`cat /proc/$$/comm`
grep "parent_comm: $COMM" events/sched/sched_process_fork/hist > /dev/null || \
fail "string key on sched_process_fork did not work"
reset_trigger
echo "Test histogram with its name"
echo 'hist:name=test_hist:keys=common_pid' > events/sched/sched_process_fork/trigger
for i in `seq 1 10` ; do ( echo "forked" > /dev/null); done
grep test_hist events/sched/sched_process_fork/hist > /dev/null || \
fail "named event on sched_process_fork did not work"
echo "Test same named histogram on different events"
echo 'hist:name=test_hist:keys=common_pid' > events/sched/sched_process_exit/trigger
for i in `seq 1 10` ; do ( echo "forked" > /dev/null); done
grep test_hist events/sched/sched_process_exit/hist > /dev/null || \
fail "named event on sched_process_fork did not work"
diffs=`diff events/sched/sched_process_exit/hist events/sched/sched_process_fork/hist | wc -l`
test $diffs -eq 0 || fail "Same name histograms are not same"
reset_trigger
do_reset
exit 0
tools/testing/selftests/ftrace/test.d/trigger/trigger-snapshot.tc 0 → 100644
View file @ 2600a46e
#!/bin/sh
# description: event trigger - test snapshot-trigger
do_reset() {
reset_trigger
echo > set_event
clear_trace
}
fail() { #msg
do_reset
echo $1
exit $FAIL
}
if [ ! -f set_event -o ! -d events/sched ]; then
echo "event tracing is not supported"
exit_unsupported
fi
if [ ! -f events/sched/sched_process_fork/trigger ]; then
echo "event trigger is not supported"
exit_unsupported
fi
reset_tracer
do_reset
FEATURE=`grep snapshot events/sched/sched_process_fork/trigger`
if [ -z "$FEATURE" ]; then
echo "snapshot trigger is not supported"
exit_unsupported
fi
echo "Test snapshot tigger"
echo 0 > snapshot
echo 1 > events/sched/sched_process_fork/enable
( echo "forked")
echo 'snapshot:1' > events/sched/sched_process_fork/trigger
( echo "forked")
grep sched_process_fork snapshot > /dev/null || \
fail "snapshot trigger on sched_process_fork did not work"
reset_trigger
echo 0 > snapshot
echo 0 > events/sched/sched_process_fork/enable
echo "Test snapshot semantic errors"
! echo "snapshot+1" > events/sched/sched_process_fork/trigger
echo "snapshot" > events/sched/sched_process_fork/trigger
! echo "snapshot" > events/sched/sched_process_fork/trigger
do_reset
exit 0
tools/testing/selftests/ftrace/test.d/trigger/trigger-stacktrace.tc 0 → 100644
View file @ 2600a46e
#!/bin/sh
# description: event trigger - test stacktrace-trigger
do_reset() {
reset_trigger
echo > set_event
clear_trace
}
fail() { #msg
do_reset
echo $1
exit $FAIL
}
if [ ! -f set_event -o ! -d events/sched ]; then
echo "event tracing is not supported"
exit_unsupported
fi
if [ ! -f events/sched/sched_process_fork/trigger ]; then
echo "event trigger is not supported"
exit_unsupported
fi
reset_tracer
do_reset
FEATURE=`grep stacktrace events/sched/sched_process_fork/trigger`
if [ -z "$FEATURE" ]; then
echo "stacktrace trigger is not supported"
exit_unsupported
fi
echo "Test stacktrace tigger"
echo 0 > trace
echo 0 > options/stacktrace
echo 'stacktrace' > events/sched/sched_process_fork/trigger
( echo "forked")
grep "<stack trace>" trace > /dev/null || \
fail "stacktrace trigger on sched_process_fork did not work"
reset_trigger
echo "Test stacktrace semantic errors"
! echo "stacktrace:foo" > events/sched/sched_process_fork/trigger
echo "stacktrace" > events/sched/sched_process_fork/trigger
! echo "stacktrace" > events/sched/sched_process_fork/trigger
do_reset
exit 0
tools/testing/selftests/ftrace/test.d/trigger/trigger-traceonoff.tc 0 → 100644
View file @ 2600a46e
#!/bin/sh
# description: event trigger - test traceon/off trigger
do_reset() {
reset_trigger
echo > set_event
clear_trace
}
fail() { #msg
do_reset
echo $1
exit $FAIL
}
if [ ! -f set_event -o ! -d events/sched ]; then
echo "event tracing is not supported"
exit_unsupported
fi
if [ ! -f events/sched/sched_process_fork/trigger ]; then
echo "event trigger is not supported"
exit_unsupported
fi
reset_tracer
do_reset
echo "Test traceoff trigger"
echo 1 > tracing_on
echo 'traceoff' > events/sched/sched_process_fork/trigger
( echo "forked")
if [ `cat tracing_on` -ne 0 ]; then
fail "traceoff trigger on sched_process_fork did not work"
fi
reset_trigger
echo "Test traceon trigger"
echo 0 > tracing_on
echo 'traceon' > events/sched/sched_process_fork/trigger
( echo "forked")
if [ `cat tracing_on` -ne 1 ]; then
fail "traceoff trigger on sched_process_fork did not work"
fi
reset_trigger
echo "Test semantic error for traceoff/on trigger"
! echo 'traceoff:badparam' > events/sched/sched_process_fork/trigger
! echo 'traceoff+0' > events/sched/sched_process_fork/trigger
echo 'traceon' > events/sched/sched_process_fork/trigger
! echo 'traceon' > events/sched/sched_process_fork/trigger
! echo 'traceoff' > events/sched/sched_process_fork/trigger
do_reset
exit 0
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