From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753919AbYK2S7h (ORCPT ); Sat, 29 Nov 2008 13:59:37 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752308AbYK2S7a (ORCPT ); Sat, 29 Nov 2008 13:59:30 -0500 Received: from mx2.redhat.com ([66.187.237.31]:55950 "EHLO mx2.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752270AbYK2S73 (ORCPT ); Sat, 29 Nov 2008 13:59:29 -0500 Message-ID: <49319109.7030904@redhat.com> Date: Sat, 29 Nov 2008 13:59:21 -0500 From: Rik van Riel Organization: Red Hat, Inc User-Agent: Thunderbird 2.0.0.17 (X11/20080915) MIME-Version: 1.0 To: Andrew Morton CC: linux-mm@kvack.org, linux-kernel@vger.kernel.org, KOSAKI Motohiro Subject: Re: [PATCH] vmscan: skip freeing memory from zones with lots free 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> In-Reply-To: <20081129105120.cfb8c035.akpm@linux-foundation.org> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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. 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. -- All rights reversed.