Re: [PATCH 0/5] perf kmem: Add more functions and show more statistics

Frederic Weisbecker
2009-11-24T18:49:32Z

On Tue, Nov 24, 2009 at 11:07:24AM +0100, Ingo Molnar wrote:
>
> * Li Zefan <lizf@cn.fujitsu.com> wrote:
>
> > > 3)
> > >
> > > it doesnt seem to be working on one of my boxes, which has perf and kmem
> > > events as well:
> > >
> > > aldebaran:~/linux/linux/tools/perf> perf kmem record
> > > ^C[ perf record: Woken up 1 times to write data ]
> > > [ perf record: Captured and wrote 0.050 MB perf.data (~2172 samples) ]
> > >
> >
> > Seems no kmem event is recorded. No sure what happened here.
> >
> > Might be that the parameters that perf-kmem passes to perf-record
> > are not properly selected?
> >
> > Do perf-sched and perf-timechart work on this box?
>
> yeah:
>
> aldebaran:~> perf sched record sleep 1
> [ perf record: Woken up 1 times to write data ]
> [ perf record: Captured and wrote 0.017 MB perf.data (~758 samples) ]
> aldebaran:~> perf trace | tail -5
> distccd-20944 [010] 1792.787376: sched_stat_runtime: comm=distccd pid=20944 runtime=11196 [ns] vruntime=696395420043 [ns]
> init-0 [009] 1792.914837: sched_stat_wait: comm=x86_64-linux-gc pid=881 delay=10686 [ns]
> init-0 [009] 1792.915082: sched_stat_sleep: comm=events/9 pid=44 delay=2183651362 [ns]
> as-889 [013] 1793.008008: sched_stat_runtime: comm=as pid=889 runtime=156807 [ns] vruntime=1553569219042 [ns]
> init-0 [004] 1793.154400: sched_stat_wait: comm=events/4 pid=39 delay=12155 [ns]
>
> aldebaran:~> perf kmem record sleep 1
> [ perf record: Woken up 1 times to write data ]
> [ perf record: Captured and wrote 0.078 MB perf.data (~3398 samples) ]
> aldebaran:~> perf trace | tail -5
> aldebaran:~>
>
> the perf.data has mmap and exit events - but no kmem events.
>
> I've attached the config, in case it matters. It runs latest -tip, with
> your latest series applied as well.
>
> Ingo

I think this is a problem external to kmem events. It's about
trace events/perf in general. It looks like we have some losses.
Steve and Arjan have reported similar things.

I'll investigate this way.

Thanks.