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SubjectRe: [slubllv7 04/17] x86: Add support for cmpxchg_double
On 6/1/11 8:25 PM, Christoph Lameter wrote:
> A simple implementation that only supports the word size and does not
> have a fallback mode (would require a spinlock).
>
> Add 32 and 64 bit support for cmpxchg_double. cmpxchg double uses
> the cmpxchg8b or cmpxchg16b instruction on x86 processors to compare
> and swap 2 machine words. This allows lockless algorithms to move more
> context information through critical sections.
>
> Set a flag CONFIG_CMPXCHG_DOUBLE to signal that support for double word
> cmpxchg detection has been build into the kernel. Note that each subsystem
> using cmpxchg_double has to implement a fall back mechanism as long as
> we offer support for processors that do not implement cmpxchg_double.
>
> Reviewed-by: H. Peter Anvin<hpa@zytor.com>
> Cc: tj@kernel.org
> Signed-off-by: Christoph Lameter<cl@linux.com>

Tejun, I'm going to queue this series for linux-next in the next few
days. Could you either pick up this patch so I can pull from your tree
or alternatively, is it OK to queue this through slab.git?

Pekka


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