On Wed, Jun 16, 2010 at 6:41 PM, stephane eranian <eran...@googlemail.com> wrote: > On Wed, Jun 16, 2010 at 4:52 PM, Peter Zijlstra <pet...@infradead.org> wrote: >> On Wed, 2010-06-16 at 16:40 +0200, Stephane Eranian wrote: >>> This leads me to another point. For per-thread sampling, why >>> do we need to record mmap() events happening *outside* of >>> the process? I can understand the exception of kernel modules. >> >> How does that happen? The per-thread events should be on the per-task >> context, so another task's mmap() events should never end up there. >> > > I don't see the test that says the vma does not belong to the current task. > I also don't see anything in perf_event_mmap_match(). > > It does seem to work as you said in recent kernels, though. So I am certainly > missing something here. > I think I got it now. It's all based on the current->perf_event_ctxp. So you only look at the events (and thus sampling buffers) attached to current which issued the mmap().
I found out that my problem is coming from perf creating synthetic mmap() entries for everything it finds in /proc/PID. ------------------------------------------------------------------------------ ThinkGeek and WIRED's GeekDad team up for the Ultimate GeekDad Father's Day Giveaway. ONE MASSIVE PRIZE to the lucky parental unit. See the prize list and enter to win: http://p.sf.net/sfu/thinkgeek-promo _______________________________________________ perfmon2-devel mailing list perfmon2-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/perfmon2-devel
