Messages in this thread Patch in this message | | | Date | Mon, 21 Apr 2014 18:06:55 +0200 | From | Stephane Eranian <> | Subject | [PATCH] perf tools: fix processing of pid/tid for mmap records |
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perf tools: fix processing of pid/tid for mmap records
Mmaps are global to a process (always). Processing them per-thread was causing some serious issues in case mmaps would overlap. The overlap fixups would only occur in the context of the thread which generated the overlapping mmap. But that was cause issues later on when a sample from another thread would fall into that overlapping mmap.
The solution to the problem is to handle ALL mmaps as occurring in the master thread (pid = tid) and then to lookup for thread map using pid as the tid argument. This is how samples are looking up for the thread map already (notice pid passed twice):
int perf_event__preprocess_sample(const union perf_event *event, struct machine *machine, struct addr_location *al, struct perf_sample *sample) { struct thread *thread = machine__findnew_thread(machine, sample->pid, sample->pid); } Without this fix, some samples in overlapping regions may not be symbolized. Signed-off-by: Stephane Eranian <eranian@google.com>
diff --git a/tools/perf/util/machine.c b/tools/perf/util/machine.c index a53cd0b..43cdc0a 100644 --- a/tools/perf/util/machine.c +++ b/tools/perf/util/machine.c @@ -1025,9 +1025,9 @@ int machine__process_mmap2_event(struct machine *machine, goto out_problem; return 0; } - + /* only look by pid for mmap events */ thread = machine__findnew_thread(machine, event->mmap2.pid, - event->mmap2.tid); + event->mmap2.pid); if (thread == NULL) goto out_problem; @@ -1073,9 +1073,9 @@ int machine__process_mmap_event(struct machine *machine, union perf_event *event goto out_problem; return 0; } - + /* only look by pid for mmap events */ thread = machine__findnew_thread(machine, event->mmap.pid, - event->mmap.tid); + event->mmap.pid); if (thread == NULL) goto out_problem;
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