From mboxrd@z Thu Jan 1 00:00:00 1970 Date: Tue, 18 Sep 2007 11:03:37 -0700 From: Andrew Morton Subject: Re: [PATCH] mm: use pagevec to rotate reclaimable page Message-Id: <20070918110337.7d23b3aa.akpm@linux-foundation.org> In-Reply-To: <200709181147.45006.nickpiggin@yahoo.com.au> References: <6.0.0.20.2.20070907113025.024dfbb8@172.19.0.2> <200709181129.50253.nickpiggin@yahoo.com.au> <20070918104435.2ba25ff3.akpm@linux-foundation.org> <200709181147.45006.nickpiggin@yahoo.com.au> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org Return-Path: To: Nick Piggin Cc: Hisashi Hifumi , linux-kernel@vger.kernel.org, linux-mm@kvack.org List-ID: On Tue, 18 Sep 2007 11:47:44 +1000 Nick Piggin wrote: > On Wednesday 19 September 2007 03:44, Andrew Morton wrote: > > On Tue, 18 Sep 2007 11:29:50 +1000 Nick Piggin > 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. hmm. > > > > 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 ;) Yes, I wonder that. Some of the additional overhead will come from the additional get_page/put_page which is needed for pagevec ownership. -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org