Re: [PATCH 2.6.13] lockless pagecache 2/7

Nick Piggin
2005-09-02T21:26:15Z

Christoph Lameter wrote:
> On Fri, 2 Sep 2005, Nick Piggin wrote:
>
>
>>Implement atomic_cmpxchg for i386 and ppc64. Is there any
>>architecture that won't be able to implement such an operation?
>
>
> Something like that used to be part of the page fault scalability
> patchset. You contributed to it last year. Here is the latest version of
> that. May need some work though.
>

Thanks Christoph, I think this will be required to support 386.
In the worst case, we could provide a fallback path and take
->tree_lock in pagecache lookups if there is no atomic_cmpxchg,
however I would much prefer all architectures get an atomic_cmpxchg,
and I think it should turn out to be a generally useful primitive.

I may trim this down to only provide what is needed for atomic_cmpxchg
if that is OK?

Nick

--
SUSE Labs, Novell Inc.

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