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  1. 21 Dec, 2010 2 commits
    • Ian Munsie's avatar
      perf record,report,annotate,diff: Process events in order · eac23d1c
      Ian Munsie authored 
      This patch changes perf report to ask for the ID info on all events be
default if recording from multiple CPUs.

Perf report, annotate and diff will now process the events in order if
the kernel is able to provide timestamps on all events. This ensures
that events such as COMM and MMAP which are necessary to correctly
interpret samples are processed prior to those samples so that they are
attributed correctly.

Before:
 # perf record ./cachetest
 # perf report

 # Events: 6K cycles
 #
 # Overhead  Command      Shared Object                           Symbol
 # ........  .......  .................  ...............................
 #
     74.11%    :3259  [unknown]          [k] 0x4a6c
      1.50%  cachetest  ld-2.11.2.so       [.] 0x1777c
      1.46%    :3259  [kernel.kallsyms]  [k] .perf_event_mmap_ctx
      1.25%    :3259  [kernel.kallsyms]  [k] restore
      0.74%    :3259  [kernel.kallsyms]  [k] ._raw_spin_lock
      0.71%    :3259  [kernel.kallsyms]  [k] .filemap_fault
      0.66%    :3259  [kernel.kallsyms]  [k] .memset
      0.54%  cachetest  [kernel.kallsyms]  [k] .sha_transform
      0.54%    :3259  [kernel.kallsyms]  [k] .copy_4K_page
      0.54%    :3259  [kernel.kallsyms]  [k] .find_get_page
      0.52%    :3259  [kernel.kallsyms]  [k] .trace_hardirqs_off
      0.50%    :3259  [kernel.kallsyms]  [k] .__do_fault
<SNIP>

After:
 # perf report

 # Events: 6K cycles
 #
 # Overhead  Command      Shared Object                           Symbol
 # ........  .......  .................  ...............................
 #
     44.28%  cachetest  cachetest          [.] sumArrayNaive
     22.53%  cachetest  cachetest          [.] sumArrayOptimal
      6.59%  cachetest  ld-2.11.2.so       [.] 0x1777c
      2.13%  cachetest  [unknown]          [k] 0x340
      1.46%  cachetest  [kernel.kallsyms]  [k] .perf_event_mmap_ctx
      1.25%  cachetest  [kernel.kallsyms]  [k] restore
      0.74%  cachetest  [kernel.kallsyms]  [k] ._raw_spin_lock
      0.71%  cachetest  [kernel.kallsyms]  [k] .filemap_fault
      0.66%  cachetest  [kernel.kallsyms]  [k] .memset
      0.54%  cachetest  [kernel.kallsyms]  [k] .copy_4K_page
      0.54%  cachetest  [kernel.kallsyms]  [k] .find_get_page
      0.54%  cachetest  [kernel.kallsyms]  [k] .sha_transform
      0.52%  cachetest  [kernel.kallsyms]  [k] .trace_hardirqs_off
      0.50%  cachetest  [kernel.kallsyms]  [k] .__do_fault
<SNIP>

Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
LKML-Reference: <1291872833-839-1-git-send-email-imunsie@au1.ibm.com>
Signed-off-by: default avatarIan Munsie <imunsie@au1.ibm.com>
Signed-off-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
      eac23d1c
    • Ian Munsie's avatar
      perf session: Fallback to unordered processing if no sample_id_all · 21ef97f0
      Ian Munsie authored 
      If we are running the new perf on an old kernel without support for
sample_id_all, we should fall back to the old unordered processing of
events. If we didn't than we would *always* process events without
timestamps out of order, whether or not we hit a reordering race. In
other words, instead of there being a chance of not attributing samples
correctly, we would guarantee that samples would not be attributed.

While processing all events without timestamps before events with
timestamps may seem like an intuitive solution, it falls down as
PERF_RECORD_EXIT events would also be processed before any samples.
Even with a workaround for that case, samples before/after an exec would
not be attributed correctly.

This patch allows commands to indicate whether they need to fall back to
unordered processing, so that commands that do not care about timestamps
on every event will not be affected. If we do fallback, this will print
out a warning if report -D was invoked.

This patch adds the test in perf_session__new so that we only need to
test once per session. Commands that do not use an event_ops (such as
record and top) can simply pass NULL in it's place.
Acked-by: default avatarThomas Gleixner <tglx@linutronix.de>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
LKML-Reference: <1291951882-sup-6069@au1.ibm.com>
Signed-off-by: default avatarIan Munsie <imunsie@au1.ibm.com>
Signed-off-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
      21ef97f0
  3. 16 Dec, 2010 9 commits
  5. 13 Dec, 2010 1 commit
  7. 09 Dec, 2010 15 commits
  9. 08 Dec, 2010 10 commits
  11. 07 Dec, 2010 3 commits
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