Re: [PATCH] sched: fix the theoretical signal_wake_up() vsschedule() race

[Oleg Nesterov]

On 08/13, Peter Zijlstra wrote:
>
> On Mon, Aug 12, 2013 at 07:02:57PM +0200, Oleg Nesterov wrote:
> > +/*
> > + * Despite its name it doesn't necessarily has to be a full barrier.
> > + * It should only guarantee that a STORE before the critical section
> > + * can not be reordered with a LOAD inside this section.
> > + * So the default implementation simply ensures that a STORE can not
> > + * move into the critical section, smp_wmb() should serialize it with
> > + * another STORE done by spin_lock().
> > + */
> > +#ifndef smp_mb__before_spinlock
> > +#define smp_mb__before_spinlock()	smp_wmb()
> >  #endif
>
> I would have expected mention of the ACQUIRE of the lock keeping the
> LOAD inside the locked section.

OK, please see v2 below.

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