Re: [PATCH][RFC] Measuring term of acquiring spinlock

From: Frederic Weisbecker
Date: Fri Nov 13 2009 - 03:40:40 EST


On Fri, Nov 13, 2009 at 09:17:22AM +0100, Ingo Molnar wrote:
>
> * Hitoshi Mitake <mitake@xxxxxxxxxxxxxxxxxxxxx> wrote:
>
> > From: Ingo Molnar <mingo@xxxxxxx>
> > Subject: Re: [PATCH][RFC] Measuring term of acquiring spinlock
> > Date: Thu, 12 Nov 2009 08:39:09 +0100
> >
> > >
> > > * Hitoshi Mitake <mitake@xxxxxxxxxxxxxxxxxxxxx> wrote:
> > >
> > > > * Description
> > > >
> > > > This patch makes the file spinlock_stats on top of the debugfs.
> > > > When user reads this file, some statistical data related to
> > > > spinlocks are printed.
> > >
> > > hm, are you aware of the lockstat tracepoints? They do something
> > > like this - and it utilizes perf events to report these events. See
> > > include/trace/events/lockdep.h. Needs CONFIG_LOCK_STAT enabled.
> > >
> >
> > Wow, I didn't know that. I'll try it.
>
> Btw., i think we should rename that tracepoint category from 'lockdep'
> to 'lock'. It's possible to enable them without CONFIG_PROVE_LOCKING,
> and they arent high-overhead in that case.
>
> Ingo


I have a pending patch for that somewhere. I can send it right away.

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