ARM perf events spin locks

Russell King - ARM Linux linux at
Tue Nov 30 09:31:41 EST 2010

On Tue, Nov 30, 2010 at 01:59:10PM -0000, Will Deacon wrote:
> > > Well struct perf_event_ctx has a lock field which is of type raw_spinlock_t.
> > > I *think* this is always held by the core perf code before calling the backend,
> > > however IRQs may still be enabled so we probably do need to change our pmu_lock.
> > >
> > > Is that a sane analysis?
> > That sounds perfectly reasonable to me! We don't hold these locks for any
> > potentially long periods of time so it's probably better to be safe! Do you
> > want me to make this change after perf-split is merged or is that something
> > you're happy to do?
> I don't mind doing it as a separate patch after Russell has pulled my
> perf-split branch.

You mean this?

commit f1690d17d2c7afa2a2079e3c91eb2bca8c1c5ecd
Merge: 612275a 43eab87
Author: Russell King <rmk+kernel at>
Date:   Fri Nov 26 10:26:43 2010 +0000

    Merge branch 'perf-split' of git:// into devel-stable

Sorry, I didn't push the tree out for a week or so because I was busy with
other things (like the pgtable stuff.)

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