- 15 May, 2009 4 commits
-
-
Li Zefan authored
We should leave the last slot for the ending '\0'. [ Impact: fix possible crash when the length of an operand is 128 ] Signed-off-by:
Li Zefan <lizf@cn.fujitsu.com> LKML-Reference: <4A0CDC8C.30602@cn.fujitsu.com> Signed-off-by:
Steven Rostedt <rostedt@goodmis.org>
-
Li Zefan authored
[ Impact: fix deadlock in a rare case we fail to allocate memory ] Signed-off-by:
-
Steven Rostedt authored
The stack tracer stores eight entries in the ring buffer when an event traces the stack. The output outputs all eight entries regardless of how many entries were recorded. This patch breaks out of the loop when a null entry is discovered. [ Impact: only print the stack that is recorded ] Signed-off-by: -
Steven Rostedt authored
If we return -1 in the ops->stack for the stacktrace saving, we end up breaking out of the loop if the stack we are tracing is in the exception stack. This causes traces like: <idle>-0 [002] 34263.745825: raise_softirq_irqoff <-__blk_complete_request <idle>-0 [002] 34263.745826: <= 0 <= 0 <= 0 <= 0 <= 0 <= 0 <= 0 By returning "0" instead, the irq stack is saved as well, and we see: <idle>-0 [003] 883.280992: raise_softirq_irqoff <-__hrtimer_star t_range_ns <idle>-0 [003] 883.280992: <= hrtimer_start_range_ns <= tick_nohz_restart_sched_tick <= cpu_idle <= start_secondary <= <= 0 <= 0 [ Impact: record stacks from interrupts ] Signed-off-by:
-
- 12 May, 2009 3 commits
-
-
Steven Rostedt authored
This is a bit of micro-optimizations. But since the ring buffer is used in tracing every function call, it is an extreme hot path. Every nanosecond counts. This change shows over 5% improvement in the ring-buffer-benchmark. [ Impact: more efficient code ] Signed-off-by: -
Steven Rostedt authored
The ring_buffer_time_stamp that is exported adds a little more overhead than is needed for using it internally. This patch adds an internal timestamp function that can be inlined (a single line function) and used internally for the ring buffer. [ Impact: a little less overhead to the ring buffer ] Signed-off-by: -
Steven Rostedt authored
Doing some small changes in the fast path of the ring buffer recording saves over 3% in the ring-buffer-benchmark test. [ Impact: a little faster ring buffer recording ] Signed-off-by:
-
- 11 May, 2009 6 commits
-
-
Steven Rostedt authored
The event length is calculated and passed in to rb_reserve_next_event in two different locations. Having rb_reserve_next_event do the calculations directly makes only one location to do the change and causes the calculation to be inlined by gcc. Before: text data bss dec hex filename 16538 24 12 16574 40be kernel/trace/ring_buffer.o After: text data bss dec hex filename 16490 24 12 16526 408e kernel/trace/ring_buffer.o [ Impact: smaller more efficient code ] Signed-off-by: -
Steven Rostedt authored
The rb_reserve_next_event is only called for the data type (type = 0). There is no reason to pass in the type to the function. Before: text data bss dec hex filename 16554 24 12 16590 40ce kernel/trace/ring_buffer.o After: text data bss dec hex filename 16538 24 12 16574 40be kernel/trace/ring_buffer.o [ Impact: cleaner, smaller and slightly more efficient code ] Signed-off-by: -
Steven Rostedt authored
Although we check if "missed" is not zero, we divide by hit + missed, and the addition can possible overflow and become a divide by zero. This patch checks for this case, and will report it when it happens then modify "hit" to make the calculation be non zero. [ Impact: prevent possible divide by zero in ring-buffer-benchmark ] Reported-by:
Andrew Morton <akpm@linux-foundation.org> Signed-off-by:
-
Steven Rostedt authored
The use of numeric constants is discouraged. It is cleaner and more descriptive to use macros for constant time conversions. This patch also removes an extra new line. [ Impact: more descriptive time conversions ] Reported-by:
-
Li Zefan authored
The last argument of block_remap prober is the original sector before remap, so it should be 'from', not 'to'. [ Impact: clean up ] Signed-off-by:
Ingo Molnar <mingo@elte.hu>
-
Li Zefan authored
I got this: 8,0 1 305.417782332 2037 I R 32 (ffffff9e 10 00 ...) [bash] It should be: 8,0 1 305.417782332 2037 I R 32 (9e 10 00 ...) [bash] [ Impact: fix output of pc events ] Signed-off-by:
-
- 08 May, 2009 5 commits
-
-
Steven Rostedt authored
Other parts of the kernel may need to be able to enable or disable specific events. Especially parts that create trace events. [ Impact: allow enabling of trace events by those that create the event ] Signed-off-by: -
Steven Rostedt authored
Commit 8f31bfe5 tracing/events: clean up for ftrace_set_clr_event() Moved out the code for ftrace_set_clr_event into a helper funciton but did not initialize the return value. As a result, we do not warn about a typo in the echoing of events in set_event. This patch restores the old warning: # echo foobar > set_event -bash: echo: write error: Invalid argument [ Impact: restore warning of invalid entries to set_event ] Signed-off-by:
-
Li Zefan authored
A smarter way to figure out the output of an enable file. [ Impact: clean up ] Signed-off-by:
Frederic Weisbecker <fweisbec@gmail.com> LKML-Reference: <4A0399A5.2080603@cn.fujitsu.com> Signed-off-by:
-
Li Zefan authored
Add a helper function __ftrace_set_clr_event(), and replace some ftrace_set_clr_event() calls with this helper, thus we don't need any kstrdup() or kmalloc(). As a side effect, this patch fixes an issue in self tests code, which is similar to the one fixed in commit d6bf81ef ("tracing: append ":*" to internal setting of system events") It's a small issue and won't cause any bug in fact, but we should do things right anyway. [ Impact: prevent spurious event-enabling in tracing self-tests ] Signed-off-by:
-
Steven Rostedt authored
There's a WARN_ON in the ring buffer code that makes sure preemption is disabled. It checks "!preempt_count()". But when CONFIG_PREEMPT is not enabled, preempt_count() is always zero, and this will trigger the warning. [ Impact: prevent false warning on non preemptible kernels ] Signed-off-by:
-
- 07 May, 2009 13 commits
-
-
Steven Rostedt authored
It is nice to see the overhead of the benchmark test when tracing is disabled. That is, we turn off the ring buffer just to see what the cost of running the loop that calls into the ring buffer is. Currently, if no entries wer made, we get 0. This is not informative. This patch changes it to check if we had any "missed" (non recorded) events. If so, a total count is also reported. [ Impact: evaluate the over head of the ring buffer benchmark test ] Signed-off-by: -
Steven Rostedt authored
Calling cond_resched at every iteration of the loop adds a bit of overhead to the benchmark. This patch does two things. 1) only calls cond-resched when CONFIG_PREEMPT is not enabled 2) only calls cond-resched after so many traces has been performed. [ Impact: less overhead to the ring-buffer-benchmark ] Signed-off-by: -
Steven Rostedt authored
Tracing can be very helpful to debug the kernel. When DEBUG_KERNEL is enabled it is nice to enable the trace menu as well. This patch only make the tracing menu enabled by default, it does not make any of the tracers enabled. And the menu is only enabled by default if DEBUG_KERNEL is enabled. [ Impact: show tracing options to those debugging the kernel ] Signed-off-by: -
Steven Rostedt authored
The system enabling of events uses the same code as the set_event file. It passes in the name of the system to the parser and that will enable all the events that has that system as a name. The problem is that it will also enable events with the same name as the system. If you have system name foo, and system name bar, but within the system bar, there exists an event called foo. By setting the system name foo, you will also be enabling the event foo in the system bar. This is not an expected result. The solution is to pass in "foo:*", which will only enable the system foo and not events called foo. [ Impact: prevent accidental enabling of events with same name as a system ] Reported-by:
-
Steven Rostedt authored
Ingo Molnar thought that the code to calculate the time in cond_resched is a bit too ugly and is not needed. This patch removes it and replaces it with a simple call to cond_resched. I kept the comment that explains the reason for the cond_resched. [ Impact: remove ugly code ] Reported-by:
-
Ingo Molnar authored
Merge reason: this topic is ready for upstream now. It passed Oleg's review and Andrew had no further mm/* objections/observations either. Signed-off-by: -
Ingo Molnar authored
Merge reason: tracing/core was on a .30-rc1 base and was missing out on on a handful of tracing fixes present in .30-rc5-almost. Signed-off-by: -
Li Zefan authored
In filter_add_subsystem_pred() we should release event_mutex before calling filter_free_subsystem_preds(), since both functions hold event_mutex. [ Impact: fix deadlock when writing invalid pred into subsystem filter ] Signed-off-by:
-
Frederic Weisbecker authored
When we set a filter for an event, such as: echo "name == my_lock_name" > \ /debug/tracing/events/lockdep/lock_acquired/filter then the following order of token type is parsed: - space - operator - parentheses - operand Because the operators and parentheses have a higher precedence than the operand characters, which is normal, then we can't use any string containing such special characters: ()=<>!&| To get this support and also avoid ambiguous intepretation from the parser or the human, we can do it using double quotes so that we keep the usual languages habits. Then after this patch you can still declare string condition like before: echo name == myname But if you want to compare against a string containing an operator character, you can use double quotes: echo 'name == "&myname"' Don't forget to include the whole expression into single quotes or the double ones will be eaten by echo. [ Impact: support strings with special characters for tracing filters ] Cc: Tom Zanussi <tzanussi@gmail.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Li Zefan <lizf@cn.fujitsu.com> Cc: Zhaolei <zhaolei@cn.fujitsu.com> Signed-off-by: -
Frederic Weisbecker authored
Currently the filtering infrastructure supports well the numeric types and fixed sized array types. But the recently added __string() field uses a specific indirect offset mechanism which requires a specific predicate. Until now it wasn't supported. This patch adds this support and implies very few changes, only a new predicate is needed, the management of this specific field can be done through the usual string helpers in the filtering infrastructure. [ Impact: support all kinds of strings in the tracing filters ] Cc: Tom Zanussi <tzanussi@gmail.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Li Zefan <lizf@cn.fujitsu.com> Cc: Zhaolei <zhaolei@cn.fujitsu.com> Signed-off-by: -
Steven Rostedt authored
With the current event directory, you can only enable individual events. The file debugfs/tracing/set_event is used to be able to enable or disable several events at once. But that can still be awkward. This patch adds hierarchical enabling of events. That is, each directory in debugfs/tracing/events has an "enable" file. This file can enable or disable all events within the directory and below. # echo 1 > /debugfs/tracing/events/enable will enable all events. # echo 1 > /debugfs/tracing/events/sched/enable will enable all events in the sched subsystem. # echo 1 > /debugfs/tracing/events/enable # echo 0 > /debugfs/tracing/events/irq/enable will enable all events, but then disable just the irq subsystem events. When reading one of these enable files, there are four results: 0 - all events this file affects are disabled 1 - all events this file affects are enabled X - there is a mixture of events enabled and disabled ? - this file does not affect any event Signed-off-by: -
Steven Rostedt authored
Li Zefan found that there's a race using the event ids of events and modules. When a module is loaded, an event id is incremented. We only have 16 bits for event ids (65536) and there is a possible (but highly unlikely) race that we could load and unload a module that registers events so many times that the event id counter overflows. When it overflows, it then restarts and goes looking for available ids. An id is available if it was added by a module and released. The race is if you have one module add an id, and then is removed. Another module loaded can use that same event id. But if the old module still had events in the ring buffer, the new module's call back would get bogus data. At best (and most likely) the output would just be garbage. But if the module for some reason used pointers (not recommended) then this could potentially crash. The safest thing to do is just reset the ring buffer if a module that registered events is removed. [ Impact: prevent unpredictable results of event id overflows ] Reported-by:
-
Steven Rostedt authored
When creating trace events for ftrace, the header file with the TRACE_EVENT macros must also have a macro called TRACE_SYSTEM. This macro describes the name of the system the TRACE_EVENTS are defined for. It also doubles as a way for the define_trace.h file to include the file that included it. For example: in irq.h #define TRACE_SYSTEM irq [...] #include <trace/define_trace.h> The define_trace will use TRACE_SYSTEM to include irq.h. But if the name of the trace system does not match the name of the trace header file, one can override it with: Which will change define_trace.h to inclued foo_trace.h instead of foo.h The sample comments this, but people that use the sample code will more likely use the code and not read the comments. This patch changes the sample code to use the TRACE_INCLUDE_FILE to better show developers how to use it. [ Impact: make sample less confusing to developers ] Reported-by:
Christoph Hellwig <hch@lst.de> Signed-off-by:
-
- 06 May, 2009 9 commits
-
-
Steven Rostedt authored
The ring buffer benchmark/test runs a producer for 10 seconds. This is done with preemption and interrupts enabled. But if the kernel is not compiled with CONFIG_PREEMPT, it basically stops everything but interrupts for 10 seconds. Although this is just a test and is not for production, this attribute can be quite annoying. It can also spawn badness elsewhere. This patch solves the issues by calling "cond_resched" when the system is not compiled with CONFIG_PREEMPT. It also keeps track of the time spent to call cond_resched such that it does not go against the time calculations. That is, if the task schedules away, the time scheduled out is removed from the test data. Note, this only works for non PREEMPT because we do not know when the task is scheduled out if we have PREEMPT enabled. [ Impact: prevent test from stopping the world for 10 seconds ] Signed-off-by: -
Steven Rostedt authored
Ingo Molnar thought the code would be cleaner if we used a function call instead of a goto for moving the tail page. After implementing this, it seems that gcc still inlines the result and the output is pretty much the same. Since this is considered a cleaner approach, might as well implement it. [ Impact: code clean up ] Signed-off-by: -
Steven Rostedt authored
The result of the allocation of the ring buffer read page in the ring buffer bench mark does not check the return to see if a page was actually allocated. This patch fixes that. [ Impact: avoid NULL dereference ] Signed-off-by: -
Steven Rostedt authored
The code in __rb_reserve_next checks on page overflow if it is the original commiter and then resets the page back to the original setting. Although this is fine, and the code is correct, it is a bit fragil. Some experimental work I did breaks it easily. The better and more robust solution is to have all commiters that overflow the page, simply subtract what they added. [ Impact: more robust ring buffer account management ] Signed-off-by: -
Christoph Hellwig authored
Use -I$(src) to add the current directory the include path. [ Impact: cleanup ] Signed-off-by:
-
Jaswinder Singh Rajput authored
This compiler warning: CC kernel/trace/trace_output.o kernel/trace/trace_output.c: In function ‘register_ftrace_event’: kernel/trace/trace_output.c:544: warning: ‘list’ may be used uninitialized in this function Is wrong as 'list' is always initialized - but GCC (4.3.2) does not recognize this relationship properly. Work around the warning by initializing the variable to NULL. [ Impact: fix false positive compiler warning ] Signed-off-by:
Jaswinder Singh Rajput <jaswinderrajput@gmail.com> Acked-by:
-
Alan D. Brunelle authored
Remove redundant from-sector parameter: it's /always/ the bio's sector passed in. [ Impact: cleanup ] Signed-off-by:
Alan D. Brunelle <alan.brunelle@hp.com> Reviewed-by:
KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: Jens Axboe <jens.axboe@oracle.com> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> LKML-Reference: <49FF517C.7000503@hp.com> Signed-off-by:
-
Alan D. Brunelle authored
This attempts to clarify names utilized during block I/O remap operations (partition, volume manager). It correctly matches up the /from/ information for both device & sector. This takes in the concept from Kosaki Motohiro and extends it to include better naming for the "device_from" field. [ Impact: cleanup ] Signed-off-by:
-
Mathieu Desnoyers authored
The orig_cpu parameter in trace_sched_migrate_task() is not necessary, it can be got by using task_cpu(p) in the probe. [ Impact: micro-optimization ] Signed-off-by:
Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca> [ modified from Mathieu's patch. The original patch is at: http://marc.info/?l=linux-kernel&m=123791201716239&w=2 ] Signed-off-by:
Xiao Guangrong <xiaoguangrong@cn.fujitsu.com> Cc: fweisbec@gmail.com Cc: rostedt@goodmis.org Cc: Li Zefan <lizf@cn.fujitsu.com> Cc: zhaolei@cn.fujitsu.com Cc: laijs@cn.fujitsu.com LKML-Reference: <49FFFDB7.1050402@cn.fujitsu.com> Signed-off-by:
-
