Re: [cpuops cmpxchg double V3 0/5] this_cpu_cmpxchg_double support

From: Tejun Heo
Date: Mon Feb 28 2011 - 05:36:47 EST

On Fri, Feb 25, 2011 at 11:38:50AM -0600, Christoph Lameter wrote:
> This patch series introduces this_cpu_cmpxchg_double().
> x86 cpus support cmpxchg16b and cmpxchg8b instuction which are capable of
> switching two words instead of one during a cmpxchg.
> Two words allow to swap more state in an atomic instruction.
> this_cpu_cmpxchg_double() is used in the slub allocator to avoid
> interrupt disable/enable in both alloc and free fastpath.
> Using the new operation significantly speeds up the fastpaths.

Pekka, Christoph, I applied the third and fifth patches to the percpu
tree. Please feel free to pull from the following branch and apply
slub changes on top of it.

git:// for-2.6.39

HEAD is b9ec40af0e18fb7d02106be148036c2ea490fdf9. As git.korg seems a
bit slow to sync these days, it may be better to pull from

ssh:// for-2.6.39

Thank you.

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