From mboxrd@z Thu Jan 1 00:00:00 1970 Date: Thu, 28 Jun 2007 18:29:47 -0700 From: Andrew Morton Subject: Re: [PATCH 01 of 16] remove nr_scan_inactive/active Message-Id: <20070628182947.d2aadefb.akpm@linux-foundation.org> In-Reply-To: <46845E68.9070508@redhat.com> References: <8e38f7656968417dfee0.1181332979@v2.random> <466C36AE.3000101@redhat.com> <20070610181700.GC7443@v2.random> <46814829.8090808@redhat.com> <20070626105541.cd82c940.akpm@linux-foundation.org> <468439E8.4040606@redhat.com> <20070628155715.49d051c9.akpm@linux-foundation.org> <46843E65.3020008@redhat.com> <20070628161350.5ce20202.akpm@linux-foundation.org> <4684415D.1060700@redhat.com> <20070628162936.9e78168d.akpm@linux-foundation.org> <46844B83.20901@redhat.com> <20070628171922.2c1bd91f.akpm@linux-foundation.org> <46845620.6020906@redhat.com> <20070628181238.372828fa.akpm@linux-foundation.org> <46845E68.9070508@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: Andrea Arcangeli , linux-mm@kvack.org List-ID: On Thu, 28 Jun 2007 21:20:40 -0400 Rik van Riel wrote: > > But for now, the question is: is this a reasonable overall design? Back > > off from contention points, block at the top-level, polling for allocatable > > memory to turn up? > > I'm not convinced. If we have already reclaimed some > pages from the inactive list, why wait in congestion_wait() > AT ALL? Well by top-level I meant top-level. The point where we either block or declare oom. We do that now in alloc_pages(), correctly I believe. The congestion_wait()s in vmscan.c might be misplaced (ie: too far down) because they could lead to us blocking when some memory actually got freed up (or became freeable?) somewhere else. To fix that we'd need to take a global look at things from within direct-reclaim, or back out of direct-reclaim back up to alloc_pages(), but remember where we were up to for the next pass. Perhaps by extending scan_control a bit and moving its instantiation up to __alloc_pages(). -- 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