From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail138.messagelabs.com (mail138.messagelabs.com [216.82.249.35]) by kanga.kvack.org (Postfix) with SMTP id C600B6B004D for ; Sun, 24 May 2009 09:43:51 -0400 (EDT) Date: Sun, 24 May 2009 22:44:30 +0900 (JST) From: KOSAKI Motohiro Subject: Re: [PATCH 4/4] zone_reclaim_mode is always 0 by default In-Reply-To: References: <20090521090549.63B5.A69D9226@jp.fujitsu.com> Message-Id: <20090524223857.0852.A69D9226@jp.fujitsu.com> MIME-Version: 1.0 Content-Type: text/plain; charset="US-ASCII" Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org To: Christoph Lameter Cc: kosaki.motohiro@jp.fujitsu.com, Robin Holt , LKML , linux-mm , Andrew Morton , Rik van Riel List-ID: sorry I missed this mail > > > Even with 128 nodes and 256 cpus, I _NEVER_ see the > > > system swapping out before allocating off node so I can certainly not > > > reproduce the situation you are seeing. > > > > hmhm. but I don't think we can assume hpc workload. > > System swapping due to zone reclaim? zone reclaim only reclaims unmapped > pages so it will not swap. Maybe some bug crept in in the recent changes? > Or you overrode the defaults for zone reclaim? I guess he use zone_reclaim_mode=7 or similar. However, I have to explain recent zone reclaim change. current zone reclaim is 1. zone reclaim can make high order reclaim (by hanns) 2. determine file-backed page by get_scan_ratio it mean, high order allocation makes lumpy zone reclaim. and shrink_inactive_list() don't care may_swap. then, zone_reclaim_mode=1 can makes swap-out if your driver makes high order allocation request. -- 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