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  1. 01 Oct, 2014 1 commit
    • Waiman Long's avatar
      perf symbols: Improve DSO long names lookup speed with rbtree · 4598a0a6
      Waiman Long authored 
      With workload that spawns and destroys many threads and processes, it
was found that perf-mem could took a long time to post-process the perf
data after the target workload had completed its operation.

The performance bottleneck was found to be the lookup and insertion of
the new DSO structures (thousands of them in this case).

In a dual-socket Ivy-Bridge E7-4890 v2 machine (30-core, 60-thread), the
perf profile below shows what perf was doing after the profiled AIM7
shared workload completed:

-     83.94%  perf  libc-2.11.3.so     [.] __strcmp_sse42
   - __strcmp_sse42
      - 99.82% map__new
           machine__process_mmap_event
           perf_session_deliver_event
           perf_session__process_event
           __perf_session__process_events
           cmd_record
           cmd_mem
           run_builtin
           main
           __libc_start_main
-     13.17%  perf  perf               [.] __dsos__findnew
     __dsos__findnew
     map__new
     machine__process_mmap_event
     perf_session_deliver_event
     perf_session__process_event
     __perf_session__process_events
     cmd_record
     cmd_mem
     run_builtin
     main
     __libc_start_main

So about 97% of CPU times were spent in the map__new() function trying
to insert new DSO entry into the DSO linked list. The whole
post-processing step took about 9 minutes.

The DSO structures are currently searched linearly. So the total
processing time will be proportional to n^2.

To overcome this performance problem, the DSO code is modified to also
put the DSO structures in a RB tree sorted by its long name in
additional to being in a simple linked list. With this change, the
processing time will become proportional to n*log(n) which will be much
quicker for large n. However, the short name will still be searched
using the old linear searching method.  With that patch in place, the
same perf-mem post-processing step took less than 30 seconds to
complete.
Signed-off-by: default avatarWaiman Long <Waiman.Long@hp.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Don Zickus <dzickus@redhat.com>
Cc: Douglas Hatch <doug.hatch@hp.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Scott J Norton <scott.norton@hp.com>
Link: http://lkml.kernel.org/r/1412098575-27863-3-git-send-email-Waiman.Long@hp.comSigned-off-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
      4598a0a6
  3. 30 Sep, 2014 1 commit
    • Waiman Long's avatar
      perf symbols: Encapsulate dsos list head into struct dsos · 8fa7d87f
      Waiman Long authored 
      This is a precursor patch to enable long name searching of DSOs using
a rbtree.

In this patch, a new dsos structure is created which contains only a
list head structure for the moment.

The new dsos structure is used, in turn, in the machine structure for
the user_dsos and kernel_dsos fields.

Only the following 3 dsos functions are modified to accept the new dsos
structure parameter instead of list_head:

 - dsos__add()
 - dsos__find()
 - __dsos__findnew()
Signed-off-by: default avatarWaiman Long <Waiman.Long@hp.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Don Zickus <dzickus@redhat.com>
Cc: Douglas Hatch <doug.hatch@hp.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Scott J Norton <scott.norton@hp.com>
Link: http://lkml.kernel.org/r/1412021249-19201-2-git-send-email-Waiman.Long@hp.com
[ Move struct dsos to dso.h to reduce the dso methods depends on machine.h ]
Signed-off-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
      8fa7d87f
  5. 29 Sep, 2014 4 commits
  7. 27 Sep, 2014 1 commit
    • Ingo Molnar's avatar
      Merge tag 'perf-core-for-mingo' of... · 07394b5f
      Ingo Molnar authored 
      Merge tag 'perf-core-for-mingo' of git://git.kernel.org/pub/scm/linux/kernel/git/acme/linux into perf/core

Pull perf/core improvements and fixes from Arnaldo Carvalho de Melo:

User visible changes:

  o Restore "--callchain graph" output, broken in recent cset to end
    up being the same as "fractal" (Namhyung Kim)

  o Allow profiling when kptr_restrict == 1 for non root users,
    kernel samples will just remain unresolved (Andi Kleen)

  o Allow configuring default options for callchains in config file (Namhyung Kim)

  o Fix line number in the config file error message (Jiri Olsa)

  o Fix --per-core on multi socket systems (Andi Kleen)

Cleanups:

  o Use ACCESS_ONCE() instead of volatile cast. (Pranith Kumar)

  o Modify error code for when perf_session__new() fails (Taeung Song)
Signed-off-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: default avatarIngo Molnar <mingo@kernel.org>
      07394b5f
  9. 26 Sep, 2014 11 commits
  11. 25 Sep, 2014 14 commits
    • Arnaldo Carvalho de Melo's avatar
      perf trace: Filter out POLLHUP'ed file descriptors · 46fb3c21
      Arnaldo Carvalho de Melo authored 
      So that we don't continue polling on vanished file descriptors, i.e.
file descriptors for events monitoring threads that exited.

I.e. the following 'trace' command now exits as expected, instead
of staying in an eternal loop:

      $ sleep 5s &
      $ trace -p `pidof sleep`
Reported-by: default avatarJiri Olsa <jolsa@redhat.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Don Zickus <dzickus@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/n/tip-6qegv786zbf6i8us6t4rxug9@git.kernel.orgSigned-off-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
      46fb3c21
    • Arnaldo Carvalho de Melo's avatar
      perf record: Filter out POLLHUP'ed file descriptors · 6dcf45ef
      Arnaldo Carvalho de Melo authored 
      So that we don't continue polling on vanished file descriptors, i.e.
file descriptors for events monitoring threads that exited.

I.e. the following 'perf record' command now exits as expected, instead
of staying in an eternal loop:

  $ sleep 5s &
  $ perf record -p `pidof sleep`
Reported-by: default avatarJiri Olsa <jolsa@redhat.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Don Zickus <dzickus@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/n/tip-8dg8o21t2ntzly2bfh53p3sg@git.kernel.orgSigned-off-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
      6dcf45ef
    • Arnaldo Carvalho de Melo's avatar
      perf evlist: Unmap when all refcounts to fd are gone and events drained · e4b356b5
      Arnaldo Carvalho de Melo authored 
      As noticed by receiving a POLLHUP for all its pollfd entries.

That will remove the refcount taken in perf_evlist__mmap_per_evsel(),
and when all events are consumed via perf_evlist__mmap_read() +
perf_evlist__mmap_consume(), the ring buffer will be unmap'ed.

Thanks to Jiri Olsa for pointing out that we must wait till all events
are consumed, not being ok to unmmap just when receiving all the
POLLHUPs.

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Borislav Petkov <bp@suse.de>
Cc: Corey Ashford <cjashfor@linux.vnet.ibm.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Jean Pihet <jean.pihet@linaro.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/n/tip-t10w1xk4myp7ca7m9fvip6a0@git.kernel.orgSigned-off-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
      e4b356b5
    • Arnaldo Carvalho de Melo's avatar
      tools lib fd array: Allow associating an integer cookie with each entry · 2171a925
      Arnaldo Carvalho de Melo authored 
      We will use this in perf's evlist class so that it can, at
fdarray__filter() time, to unmap the associated ring buffer.

We may need to have further info associated with each fdarray entry, in
that case we'll make that int array a 'union fdarray_priv' one and put a
pointer there so that users can stash whatever they want there. For now,
an int is enough tho.

v2: Add clarification to the per array entry priv area, as well as make
    it a union, which makes usage a bit longer, but if/when we make it
    use more space by allowing per entry pointers existing users source
    code will not have to be changed, just rebuilt.

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Borislav Petkov <bp@suse.de>
Cc: Corey Ashford <cjashfor@linux.vnet.ibm.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Jean Pihet <jean.pihet@linaro.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>

Link: http://lkml.kernel.org/n/tip-0p00bn83quck3fio3kcs9vca@git.kernel.org
      2171a925
    • Arnaldo Carvalho de Melo's avatar
      perf evlist: Refcount mmaps · 82396986
      Arnaldo Carvalho de Melo authored 
      We need to know how many fds are using a perf mmap via
PERF_EVENT_IOC_SET_OUTPUT, so that we can know when to ditch an mmap,
refcount it.

v2: Automatically unmap it when the refcount hits one, which will happen
when all fds are filtered by perf_evlist__filter_pollfd(), in later
patches.

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Borislav Petkov <bp@suse.de>
Cc: Corey Ashford <cjashfor@linux.vnet.ibm.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Jean Pihet <jean.pihet@linaro.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/20140908153824.GG2773@kernel.org
Link: http://lkml.kernel.org/n/tip-cpv7v2lw0g74ucmxa39xdpms@git.kernel.orgSigned-off-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
      82396986
    • Arnaldo Carvalho de Melo's avatar
      tools lib api: Adopt fdarray class from perf's evlist · 1b85337d
      Arnaldo Carvalho de Melo authored 
      The extensible file description array that grew in the perf_evlist class
can be useful for other tools, as it is not something that only evlists
need, so move it to tools/lib/api/fd to ease sharing it.

v2: Don't use {} like in:

 libapi_dirs:
	$(QUIET_MKDIR)mkdir -p $(OUTPUT){fs,fd}/

in Makefiles, as it will not work in some systems, as in ubuntu13.10.

v3: Add fd/*.[ch] to LIBAPIKFS_SOURCES (Fix from Jiri Olsa)

v4: Leave the fcntl(fd, O_NONBLOCK) in the evlist layer, remains to
    be checked if it is really needed there, but has no place in the
    fdarray class (Fix from Jiri Olsa)

v5: Remove evlist details from fdarray grow/filter tests. Improve it a
    bit doing more tests about expected internal state.

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Borislav Petkov <bp@suse.de>
Cc: Corey Ashford <cjashfor@linux.vnet.ibm.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Jean Pihet <jean.pihet@linaro.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/n/tip-kleuni3hckbc3s0lu6yb9x40@git.kernel.orgSigned-off-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
      1b85337d
    • Arnaldo Carvalho de Melo's avatar
      perf evlist: Introduce poll method for common code idiom · f66a889d
      Arnaldo Carvalho de Melo authored 
      Since we have access two evlist members in all these poll calls, provide
a helper.

This will also help to make the patch introducing the pollfd class more
clear, as the evlist specific uses will be hiden away
perf_evlist__poll().
Acked-by: default avatarJiri Olsa <jolsa@kernel.org>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Corey Ashford <cjashfor@linux.vnet.ibm.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Jean Pihet <jean.pihet@linaro.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/n/tip-jr9d4aop4lvy9453qahbcgp0@git.kernel.orgSigned-off-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
      f66a889d
    • Arnaldo Carvalho de Melo's avatar
      perf kvm stat live: Use perf_evlist__add_pollfd() instead of local equivalent · 0a04c9e0
      Arnaldo Carvalho de Melo authored 
      Since we can add file descriptors to the evlist pollfd and it will
autogrow, no need to copy all events to a local pollfd array, just add
the timer and stdin file descriptors.
Reviewed-by: default avatarDavid Ahern <dsahern@gmail.com>
Acked-by: default avatarJiri Olsa <jolsa@kernel.org>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Corey Ashford <cjashfor@linux.vnet.ibm.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Jean Pihet <jean.pihet@linaro.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/n/tip-2hvp9iromiheh6rl4oaa08x5@git.kernel.orgSigned-off-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
      0a04c9e0
    • Arnaldo Carvalho de Melo's avatar
      perf tests: Add pollfd growing test · 9ae28035
      Arnaldo Carvalho de Melo authored 
        [acme@ssdandy linux]$ perf test "Add fd"
  34: Add fd to pollfd array, making it autogrow             : Ok
  [acme@ssdandy linux]$ perf test -v "Add fd"
  34: Add fd to pollfd array, making it autogrow             :
  --- start ---
  test child forked, pid 19817

  before growing array:   2 [ 1, 2 ]
  after 3rd add_pollfd:   3 [ 1, 2, 35 ]
  after 4th add_pollfd:   4 [ 1, 2, 35, 88 ]
  test child finished with 0
  ---- end ----
  Add fd to pollfd array, making it autogrow: Ok
  [acme@ssdandy linux]$
Acked-by: default avatarJiri Olsa <jolsa@kernel.org>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Corey Ashford <cjashfor@linux.vnet.ibm.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Jean Pihet <jean.pihet@linaro.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/n/tip-smflpyta146bzog7z0effjss@git.kernel.orgSigned-off-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
      9ae28035
    • Arnaldo Carvalho de Melo's avatar
      perf evlist: Allow growing pollfd on add method · ad6765dd
      Arnaldo Carvalho de Melo authored 
      This way we will be able to add more file descriptors to be polled,
like stdin or some timer fd.

At this point we might as well yank the pollfd class from evlist so that
it can be used in other places.

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Corey Ashford <cjashfor@linux.vnet.ibm.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Jean Pihet <jean.pihet@linaro.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/n/tip-o2mzsjl7taumsoc35ryol00i@git.kernel.orgSigned-off-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
      ad6765dd
    • Arnaldo Carvalho de Melo's avatar
      perf evlist: We need to poll all event file descriptors · 033fa713
      Arnaldo Carvalho de Melo authored 
      Because we want to notice when they get POLLHUP'ed, so that we can
figure out when all threads exited in a workload being monitored.

We can't just monitor the fds that were mmaped, we need to notice when
all the fds that were PERF_EVENT_IOC_SET_OUTPUT'ed too, because the mmap
stays even after the fd that originally was used to do the mmap call
went away, its only when all the set-output fds for a mmap are gone that
the mmap is.

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Don Zickus <dzickus@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/r/20140908151016.GH17728@krava.brq.redhat.com
Link: http://lkml.kernel.org/n/tip-24omlq5asrfg4uo3muuzn2bl@git.kernel.orgSigned-off-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
      033fa713
    • Arnaldo Carvalho de Melo's avatar
      perf evlist: Monitor POLLERR and POLLHUP events too · 8179672c
      Arnaldo Carvalho de Melo authored 
      We want to know when the fd went away, like when a monitored thread
exits.

If we do not monitor such events, then the tools will wait forever on
events from a vanished thread, like when running:

 $ sleep 5s &
 $ perf record -p `pidof sleep`

This builds upon the kernel patch by Jiri Olsa that actually makes a
poll on those file descriptors to return POLLHUP.

It is also needed to change the tools to use
perf_evlist__filter_pollfd() to check if there are remainings fds to
monitor or if all are gone, in which case they will exit the
poll/mmap/read loop.
Acked-by: default avatarJiri Olsa <jolsa@kernel.org>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Don Zickus <dzickus@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/n/tip-a4fslwspov0bs69nj825hqpq@git.kernel.orgSigned-off-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
      8179672c
    • Arnaldo Carvalho de Melo's avatar
      perf tests: Add test for perf_evlist__filter_pollfd() · 54dbfae3
      Arnaldo Carvalho de Melo authored 
      That will use a synthetic evlist with just what is touched by this new
method to check that it works as expected.

Output in verbose mode:

  $ perf test -v pollfd
  33: Filter fds with revents mask in a pollfd array         :
  --- start ---
  filtering all but pollfd[2]:
  before:   5 [ 5, 4, 3, 2, 1 ]
   after:   1 [ 3 ]
  filtering all but (pollfd[0], pollfd[3]):
  before:   5 [ 5, 4, 3, 2, 1 ]
   after:   2 [ 5, 2 ]
  test child finished with 0
  ---- end ----
  Filter fds with revents mask in a pollfd array: Ok
  $
Acked-by: default avatarJiri Olsa <jolsa@kernel.org>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Don Zickus <dzickus@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/n/tip-x7c8liszdvc3ocmanf2cet8p@git.kernel.orgSigned-off-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
      54dbfae3
    • Arnaldo Carvalho de Melo's avatar
      perf evlist: Introduce perf_evlist__filter_pollfd method · 1ddec7f0
      Arnaldo Carvalho de Melo authored 
      To remove all entries in evlist->pollfd[] that have revents matching at
least one of the bits in the specified mask.

It'll adjust evlist->nr_fds to the number of unfiltered fds and will
return this value, as a convenience and to avoid requiring direct access
to internal state of perf_evlist objects.

This will be used after polling the evlist fds so that we remove fds
that were closed by the kernel.
Acked-by: default avatarJiri Olsa <jolsa@kernel.org>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Don Zickus <dzickus@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/n/tip-y2sca7z3wicvvy40a50lozwm@git.kernel.orgSigned-off-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
      1ddec7f0
  13. 24 Sep, 2014 8 commits
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