From: Namhyung Kim namhyung@kernel.org
commit ce9f1c05d2edfa6cdf2c1a510495d333e11810a8 upstream.
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: f7fc0d1c915a74ff ("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 Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- tools/perf/builtin-inject.c | 1 + 1 file changed, 1 insertion(+)
--- a/tools/perf/builtin-inject.c +++ b/tools/perf/builtin-inject.c @@ -538,6 +538,7 @@ static int perf_event__repipe_buildid_mm dso->hit = 1; } dso__put(dso); + perf_event__repipe(tool, event, sample, machine); return 0; }