perf lock contention: Add data failure stat
authorNamhyung Kim <namhyung@kernel.org>
Thu, 6 Apr 2023 21:06:08 +0000 (14:06 -0700)
committerArnaldo Carvalho de Melo <acme@redhat.com>
Fri, 7 Apr 2023 00:52:31 +0000 (21:52 -0300)
commit954cdac74e1e7aca518c8ef49d4fa70c8ae72d7b
tree6b1459c1622e59f81648910fe3cfe537cae0a47d
parent2d8d016527928ad65ad1fe11c9943d8b81f05d18
perf lock contention: Add data failure stat

It's possible to fail to update the data when the lock_stat map is full.
We should check that case and show the number at the end.

  $ sudo ./perf lock con -ablv -E3 -- ./perf bench sched messaging
  ...
   contended   total wait     max wait     avg wait            address   symbol

        6157    208.48 ms     69.29 us     33.86 us   ffff934c001c1f00    (spinlock)
        4030     72.04 ms     61.84 us     17.88 us   ffff934c000415c0    (spinlock)
        3201     50.30 ms     47.73 us     15.71 us   ffff934c2eead850    (spinlock)

  === output for debug ===

  bad: 0, total: 13388
  bad rate: 0.00 %
  histogram of failure reasons
         task: 0
        stack: 0
         time: 0
         data: 0      <----- added

Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Acked-by: Ian Rogers <irogers@google.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Hao Luo <haoluo@google.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Juri Lelli <juri.lelli@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Song Liu <song@kernel.org>
Cc: bpf@vger.kernel.org
Link: https://lore.kernel.org/r/20230406210611.1622492-2-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
tools/perf/builtin-lock.c
tools/perf/util/bpf_lock_contention.c
tools/perf/util/bpf_skel/lock_contention.bpf.c
tools/perf/util/lock-contention.h