Re: [PATCH 3/3] kref: Remove the memory barriers

From: Oliver Neukum
Date: Tue Dec 13 2011 - 04:48:24 EST


Am Dienstag, 13. Dezember 2011, 10:12:20 schrieb Peter Zijlstra:
> On Mon, 2011-12-12 at 23:56 +0100, Oliver Neukum wrote:
> > I guess I worried not about the increment, but the decrement.
> > Which makes me wonder what happens if you don't intend
> > to get the kref again, but need to make sure it is usually freed,
> > like:
> >
> > CPU A CPU B
> >
> > kref_get(p)
> > start_io(p)
> > [interrupt from IO]
> > kref_put(p)
>
> I would expect that if something was needed here, the io stack would
> provide the barriers since the io completion will probably want to
> change state set by the start_io thing.

> Anyway, I would put this squarely outside the responsibility of kref.

I agree, so let's remove it.

Regards

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