Messages in this thread | ![/](/images/icornerl.gif) | | Date | Tue, 22 Apr 2014 15:37:30 +0200 | Subject | Re: [PATCH] perf tools: fix processing of pid/tid for mmap records | From | Stephane Eranian <> |
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Jiri,
On Tue, Apr 22, 2014 at 3:32 PM, Jiri Olsa <jolsa@redhat.com> wrote: > hi, > > On Mon, Apr 21, 2014 at 06:06:55PM +0200, Stephane Eranian wrote: >> perf tools: fix processing of pid/tid for mmap records > > extra description line ^^^ > >> >> 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. > > could you please take a look on following patchset: > http://marc.info/?l=linux-kernel&m=139749074531132&w=2 > > this makes the map groups shared within the process, > so it should fix above issue as well > It could probably solve my problem. I will try it out.
I am wondering why the tid was taken into consideration in the first place when looking for maps? why was pid not enough?
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