Re: [RFC GIT PULL] perf/trace/lock optimization/scalability improvements

[Frederic Weisbecker <fweisbec@gmail.com>]

On Wed, Feb 03, 2010 at 10:21:43PM +0100, Jens Axboe wrote:
> On Wed, Feb 03 2010, Frederic Weisbecker wrote:
> > > So while this is orders of magnitude better than the previous patchset,
> > > it's still not anywhere near lean. But I expect you know that, just
> > > consider this a 'I tested it and this is what happened' report :-)
> > 
> > 
> > Ok, thanks a lot, the fact you can test on a 64 threads box is critically
> > helpful.
> 
> My pleasure, I'd love to have a fast and functional perf lockstat. If my
> testing helps getting there, consider me signed up :-)



Great :)


> > I also wonder what happens after this patch applied:
> > 
> > diff --git a/kernel/perf_event.c b/kernel/perf_event.c
> > index 98fd360..254b3d4 100644
> > --- a/kernel/perf_event.c
> > +++ b/kernel/perf_event.c
> > @@ -3094,7 +3094,8 @@ static u32 perf_event_tid(struct perf_event *event, struct task_struct *p)
> >         if (event->parent)
> >                 event = event->parent;
> >  
> > -       return task_pid_nr_ns(p, event->ns);
> > +       return p->pid;
> >  }
> > 
> > In my box it has increased the speed from 2x this patchset.
> 
> Cool, I'll give that a spin in the morning, the box is off atm.


Thanks a lot!