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From: Nick Piggin <nickpiggin@yahoo.com.au>
To: Andrew Morton <akpm@linux-foundation.org>
Subject: Re: [PATCH] mm: use pagevec to rotate reclaimable page
Date: Tue, 18 Sep 2007 11:47:44 +1000
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Cc: Hisashi Hifumi <hifumi.hisashi@oss.ntt.co.jp>,
       linux-kernel@vger.kernel.org, linux-mm@kvack.org
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On Wednesday 19 September 2007 03:44, Andrew Morton wrote:
> On Tue, 18 Sep 2007 11:29:50 +1000 Nick Piggin <nickpiggin@yahoo.com.au> 
wrote:
> > It would be interesting to test -mm kernels. They have a patch which
> > reduces zone lock contention quite a lot.
>
> They do?  Which patch?

Hmm... mm-buffered-write-cleanup.patch.


> > I think your patch is a nice idea, and with less zone lock contention in
> > other areas, it is possible that it might produce a relatively larger
> > improvement.
>
> I'm a bit wobbly about this patch - it adds additional single-cpu overhead
> to reduce multiple-cpu overhead and latency.

Yeah, that's true. Although maybe it gets significantly more after the
patch in -mm.

Possibly other page batching sites have similar issues on UP... I wonder
if a type of pagevec that turns into a noop on UP would be interesting...
probably totally unmeasurable and not worth the cost of code
maintenance ;)
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