Re: SLUB: Avoid atomic operation for slab_unlock

From: Christoph Lameter
Date: Thu Oct 18 2007 - 21:21:21 EST


On Fri, 19 Oct 2007, Nick Piggin wrote:

> Ah, thanks, but can we just use my earlier patch that does the
> proper __bit_spin_unlock which is provided by
> bit_spin_lock-use-lock-bitops.patch

Ok.

> This primitive should have a better chance at being correct, and
> also potentially be more optimised for each architecture (it
> only has to provide release consistency).

Yes that is what I attempted to do with the write barrier. To my knowledge
there are no reads that could bleed out and I wanted to avoid a full fence
instruction there.

> I have attached the patch here just for reference, but actually
> I am submitting it properly as part of a patch series today, now
> that the base bit lock patches have been sent upstream.

Good. Andrew: Drop my patch when this goes in.
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