Re: [PATCHv4 2/2] memory barrier: adding smp_mb__after_lock

From: Jiri Olsa
Date: Fri Jul 03 2009 - 03:50:33 EST


On Fri, Jul 03, 2009 at 09:41:26AM +0200, Jiri Olsa wrote:
> On Thu, Jul 02, 2009 at 07:39:04AM -0700, Davide Libenzi wrote:
> > On Thu, 2 Jul 2009, Eric Dumazet wrote:
> >
> > > Jiri Olsa a écrit :
> > > > Adding smp_mb__after_lock define to be used as a smp_mb call after
> > > > a lock.
> > > >
> > > > Making it nop for x86, since {read|write|spin}_lock() on x86 are
> > > > full memory barriers.
> > > >
> > > > wbr,
> > > > jirka
> > > >
> > > >
> > > > Signed-off-by: Jiri Olsa <jolsa@xxxxxxxxxx>
> > >
> > >
> > > Maybe we should remind that sk_has_helper() is always called
> > > right after a call to read_lock() as in :
> > >
> > > read_lock(&sk->sk_callback_lock);
> > > if (sk_has_sleeper(sk))
> > > wake_up_interruptible_all(sk->sk_sleep);
> >
> > Agreed, that'd be to have it in the source code comment.
> >
> >
> > - Davide
> >
>
> ok, I'll add it to the 1/2 part in v5
>
> jirka

actually I see the 2/2 would be better :)

jirka
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