Minki/linux
1
0
Fork 1
mirror of https://github.com/torvalds/linux.git synced 2024-11-27 06:31:52 +00:00
Code Issues Packages Projects Releases Wiki Activity

perf inject: Fix --buildid-all not to eat up MMAP2

Browse Source 
When MMAP2 has the PERF_RECORD_MISC_MMAP_BUILD_ID flag, it means the
record already has the build-id info.  So it marks the DSO as hit, to
skip if the same DSO is not processed if it happens to miss the build-id
later.

But it missed to copy the MMAP2 record itself so it'd fail to symbolize
samples for those regions.

For example, the following generates 249 MMAP2 events.

  $ perf record --buildid-mmap -o- true | perf report --stat -i- | grep MMAP2
           MMAP2 events:        249  (86.8%)

Adding perf inject should not change the number of events like this

  $ perf record --buildid-mmap -o- true | perf inject -b | \
  > perf report --stat -i- | grep MMAP2
           MMAP2 events:        249  (86.5%)

But when --buildid-all is used, it eats most of the MMAP2 events.

  $ perf record --buildid-mmap -o- true | perf inject -b --buildid-all | \
  > perf report --stat -i- | grep MMAP2
           MMAP2 events:          1  ( 2.5%)

With this patch, it shows the original number now.

  $ perf record --buildid-mmap -o- true | perf inject -b --buildid-all | \
  > perf report --stat -i- | grep MMAP2
           MMAP2 events:        249  (86.5%)

Committer testing:

Before:

  $ perf record --buildid-mmap -o- perf stat --null sleep 1 2> /dev/null | perf inject -b | perf report --stat -i- | grep MMAP2
           MMAP2 events:         58  (36.2%)
  $ perf record --buildid-mmap -o- perf stat --null sleep 1 2> /dev/null | perf report --stat -i- | grep MMAP2
           MMAP2 events:         58  (36.2%)
  $ perf record --buildid-mmap -o- perf stat --null sleep 1 2> /dev/null | perf inject -b --buildid-all | perf report --stat -i- | grep MMAP2
           MMAP2 events:          2  ( 1.9%)
  $

After:

  $ perf record --buildid-mmap -o- perf stat --null sleep 1 2> /dev/null | perf inject -b | perf report --stat -i- | grep MMAP2
           MMAP2 events:         58  (29.3%)
  $ perf record --buildid-mmap -o- perf stat --null sleep 1 2> /dev/null | perf report --stat -i- | grep MMAP2
           MMAP2 events:         58  (34.3%)
  $ perf record --buildid-mmap -o- perf stat --null sleep 1 2> /dev/null | perf inject -b --buildid-all | perf report --stat -i- | grep MMAP2
           MMAP2 events:         58  (38.4%)
  $

Fixes: f7fc0d1c91 ("perf inject: Do not inject BUILD_ID record if MMAP2 has it")
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20230223070155.54251-1-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
This commit is contained in:
Namhyung Kim 2023-02-22 23:01:55 -08:00 committed by Arnaldo Carvalho de Melo
parent 3ef9fec011
commit ce9f1c05d2
1 changed files with 1 additions and 0 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

1
tools/perf/builtin-inject.c
View File

@ -538,6 +538,7 @@ static int perf_event__repipe_buildid_mmap2(struct perf_tool *tool,
dso->hit = 1;
}
dso__put(dso);
perf_event__repipe(tool, event, sample, machine);
return 0;
}