Re: [PATCH 05/11] qspinlock: Optimize for smaller NR_CPUS

From: Peter Zijlstra
Date: Mon Jul 07 2014 - 10:35:32 EST


On Wed, Jun 18, 2014 at 01:39:52PM +0200, Paolo Bonzini wrote:
> Il 15/06/2014 14:47, Peter Zijlstra ha scritto:
> >
> >- for (;;) {
> >- new = (val & ~_Q_PENDING_MASK) | _Q_LOCKED_VAL;
> >-
> >- old = atomic_cmpxchg(&lock->val, val, new);
> >- if (old == val)
> >- break;
> >-
> >- val = old;
> >- }
> >+ clear_pending_set_locked(lock, val);
> > return;
>
>
> Might as well add clear_pending_set_locked already in patch 3.

Patch 4, if anywhere.

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