From mboxrd@z Thu Jan 1 00:00:00 1970 From: Nick Piggin Subject: Re: [PATCH] mm: use pagevec to rotate reclaimable page Date: Tue, 18 Sep 2007 11:29:50 +1000 References: <6.0.0.20.2.20070907113025.024dfbb8@172.19.0.2> <20070913193711.ecc825f7.akpm@linux-foundation.org> <6.0.0.20.2.20070918193944.038e2ea0@172.19.0.2> In-Reply-To: <6.0.0.20.2.20070918193944.038e2ea0@172.19.0.2> MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Content-Disposition: inline Message-Id: <200709181129.50253.nickpiggin@yahoo.com.au> Sender: owner-linux-mm@kvack.org Return-Path: To: Hisashi Hifumi Cc: Andrew Morton , linux-kernel@vger.kernel.org, linux-mm@kvack.org List-ID: On Tuesday 18 September 2007 20:41, Hisashi Hifumi wrote: > I modified my patch based on your comment. > > At 11:37 07/09/14, Andrew Morton wrote: > >So I do think that for safety and sanity's sake, we should be taking a > > ref on the pages when they are in a pagevec. That's going to hurt your > > nice performance numbers :( > > I did ping test again to observe performance deterioration caused by taking > a ref. > > -2.6.23-rc6-with-modifiedpatch > --- testmachine ping statistics --- > 3000 packets transmitted, 3000 received, 0% packet loss, time 53386ms > rtt min/avg/max/mdev = 0.074/0.110/4.716/0.147 ms, pipe 2, ipg/ewma > 17.801/0.129 ms > > The result for my original patch is as follows. > > -2.6.23-rc5-with-originalpatch > --- testmachine ping statistics --- > 3000 packets transmitted, 3000 received, 0% packet loss, time 51924ms > rtt min/avg/max/mdev = 0.072/0.108/3.884/0.114 ms, pipe 2, ipg/ewma > 17.314/0.091 ms > > > The influence to response was small. It would be interesting to test -mm kernels. They have a patch which reduces zone lock contention quite a lot. 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. -- 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