From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from m1.gw.fujitsu.co.jp ([10.0.50.71]) by fgwmail7.fujitsu.co.jp (Fujitsu Gateway) with ESMTP id mATAtFZ7021468 for (envelope-from kosaki.motohiro@jp.fujitsu.com); Sat, 29 Nov 2008 19:55:15 +0900 Received: from smail (m1 [127.0.0.1]) by outgoing.m1.gw.fujitsu.co.jp (Postfix) with ESMTP id 3824045DD76 for ; Sat, 29 Nov 2008 19:55:15 +0900 (JST) Received: from s1.gw.fujitsu.co.jp (s1.gw.fujitsu.co.jp [10.0.50.91]) by m1.gw.fujitsu.co.jp (Postfix) with ESMTP id 19AC645DD74 for ; Sat, 29 Nov 2008 19:55:15 +0900 (JST) Received: from s1.gw.fujitsu.co.jp (localhost.localdomain [127.0.0.1]) by s1.gw.fujitsu.co.jp (Postfix) with ESMTP id F0B801DB8040 for ; Sat, 29 Nov 2008 19:55:14 +0900 (JST) Received: from m108.s.css.fujitsu.com (m108.s.css.fujitsu.com [10.249.87.108]) by s1.gw.fujitsu.co.jp (Postfix) with ESMTP id A337C1DB803C for ; Sat, 29 Nov 2008 19:55:14 +0900 (JST) From: KOSAKI Motohiro Subject: Re: [PATCH] vmscan: skip freeing memory from zones with lots free In-Reply-To: <20081128231933.8daef193.akpm@linux-foundation.org> References: <20081128060803.73cd59bd@bree.surriel.com> <20081128231933.8daef193.akpm@linux-foundation.org> Message-Id: <20081129195357.813D.KOSAKI.MOTOHIRO@jp.fujitsu.com> MIME-Version: 1.0 Content-Type: text/plain; charset="US-ASCII" Content-Transfer-Encoding: 7bit Date: Sat, 29 Nov 2008 19:55:13 +0900 (JST) Sender: owner-linux-mm@kvack.org Return-Path: To: Andrew Morton Cc: kosaki.motohiro@jp.fujitsu.com, Rik van Riel , linux-mm@kvack.org, linux-kernel@vger.kernel.org List-ID: > We already tried this, or something very similar in effect, I think... > > > commit 26e4931632352e3c95a61edac22d12ebb72038fe > Author: akpm > Date: Sun Sep 8 19:21:55 2002 +0000 > > [PATCH] refill the inactive list more quickly > > Fix a problem noticed by Ed Tomlinson: under shifting workloads the > shrink_zone() logic will refill the inactive load too slowly. > > Bale out of the zone scan when we've reclaimed enough pages. Fixes a > rarely-occurring problem wherein refill_inactive_zone() ends up > shuffling 100,000 pages and generally goes silly. > > This needs to be revisited - we should go on and rebalance the lower > zones even if we reclaimed enough pages from highmem. > > > > Then it was reverted a year or two later: > > > commit 265b2b8cac1774f5f30c88e0ab8d0bcf794ef7b3 > Author: akpm > Date: Fri Mar 12 16:23:50 2004 +0000 > > [PATCH] vmscan: zone balancing fix > > We currently have a problem with the balancing of reclaim between zones: much > more reclaim happens against highmem than against lowmem. > > This patch partially fixes this by changing the direct reclaim path so it > does not bale out of the zone walk after having reclaimed sufficient pages > from highmem: go on to reclaim from lowmem regardless of how many pages we > reclaimed from lowmem. > > > My changelog does not adequately explain the reasons. > > But we don't want to rediscover these reasons in early 2010 :( Some trolling > of the linux-mm and lkml archives around those dates might help us avoid > a mistake here. I hope to digg past discussion archive. Andrew, plese wait merge this patch awhile. -- 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