From mboxrd@z Thu Jan 1 00:00:00 1970 Date: Sat, 29 Nov 2008 12:29:01 -0800 From: Andrew Morton Subject: Re: [PATCH] vmscan: skip freeing memory from zones with lots free Message-Id: <20081129122901.6243d2fa.akpm@linux-foundation.org> In-Reply-To: <49319109.7030904@redhat.com> References: <20081128060803.73cd59bd@bree.surriel.com> <20081128231933.8daef193.akpm@linux-foundation.org> <4931721D.7010001@redhat.com> <20081129094537.a224098a.akpm@linux-foundation.org> <493182C8.1080303@redhat.com> <20081129102608.f8228afd.akpm@linux-foundation.org> <49318CDE.4020505@redhat.com> <20081129105120.cfb8c035.akpm@linux-foundation.org> <49319109.7030904@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org Return-Path: To: Rik van Riel Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org, KOSAKI Motohiro List-ID: On Sat, 29 Nov 2008 13:59:21 -0500 Rik van Riel wrote: > Andrew Morton wrote: > > On Sat, 29 Nov 2008 13:41:34 -0500 Rik van Riel wrote: > > > >> Andrew Morton wrote: > >>> On Sat, 29 Nov 2008 12:58:32 -0500 Rik van Riel wrote: > >>> > >>>>> Will this new patch reintroduce the problem which > >>>>> 26e4931632352e3c95a61edac22d12ebb72038fe fixed? > >> No, that problem is already taken care of by the fact that > >> active pages always get deactivated in the current VM, > >> regardless of whether or not they were referenced. > > > > err, sorry, that was the wrong commit. > > 26e4931632352e3c95a61edac22d12ebb72038fe _introduced_ the problem, as > > predicted in the changelog. > > > > 265b2b8cac1774f5f30c88e0ab8d0bcf794ef7b3 later fixed it up. > > The patch I sent in this thread does not do any baling out, > it only skips zones where the number of free pages is more > than 4 times zone->pages_high. But that will have the same effect as baling out. Moreso, in fact. > Equal pressure is still applied to the other zones. > > This should not be a problem since we do not enter direct > reclaim unless the free pages in every zone in our zonelist > are below zone->pages_low. > > Zone skipping is only done by tasks that have been in the > direct reclaim code for a long time. >>From 265b2b8cac1774f5f30c88e0ab8d0bcf794ef7b3: We currently have a problem with the balancing of reclaim between zones: much more reclaim happens against highmem than against lowmem. This problem will be reintroduced, will it not? -- 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