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

[Ingo Molnar <mingo@elte.hu>]

* Frederic Weisbecker <fweisbec@gmail.com> wrote:

> On Fri, Nov 13, 2009 at 09:17:22AM +0100, Ingo Molnar wrote:
> > 
> > * Hitoshi Mitake <mitake@dcl.info.waseda.ac.jp> wrote:
> > 
> > > From: Ingo Molnar <mingo@elte.hu>
> > > Subject: Re: [PATCH][RFC] Measuring term of acquiring spinlock
> > > Date: Thu, 12 Nov 2009 08:39:09 +0100
> > > 
> > > > 
> > > > * Hitoshi Mitake <mitake@dcl.info.waseda.ac.jp> 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.

Cool - thanks!

	Ingo