From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757371AbZGPDnJ (ORCPT ); Wed, 15 Jul 2009 23:43:09 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1757335AbZGPDnI (ORCPT ); Wed, 15 Jul 2009 23:43:08 -0400 Received: from mx2.redhat.com ([66.187.237.31]:59003 "EHLO mx2.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757334AbZGPDnI (ORCPT ); Wed, 15 Jul 2009 23:43:08 -0400 Message-ID: <4A5EA1A4.1080502@redhat.com> Date: Wed, 15 Jul 2009 23:42:28 -0400 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: KOSAKI Motohiro , LKML , linux-mm , Wu Fengguang Subject: Re: [PATCH -mm] throttle direct reclaim when too many pages are isolated already References: <20090715223854.7548740a@bree.surriel.com> <20090715194820.237a4d77.akpm@linux-foundation.org> <4A5E9A33.3030704@redhat.com> <20090715202114.789d36f7.akpm@linux-foundation.org> <4A5E9E4E.5000308@redhat.com> <20090715203854.336de2d5.akpm@linux-foundation.org> In-Reply-To: <20090715203854.336de2d5.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 Wed, 15 Jul 2009 23:28:14 -0400 Rik van Riel wrote: >> If we are stuck at this point in the page reclaim code, >> it is because too many other tasks are reclaiming pages. >> >> That makes it fairly safe to just return SWAP_CLUSTER_MAX >> here and hope that __alloc_pages() can get a page. >> >> After all, if __alloc_pages() thinks it made progress, >> but still cannot make the allocation, it will call the >> pageout code again. > > Which will immediately return because the caller still has > fatal_signal_pending()? Other processes are in the middle of freeing pages at this point, so we should succeed in __alloc_pages() fairly quickly (and then die and free all our memory). -- All rights reversed.