From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail202.messagelabs.com (mail202.messagelabs.com [216.82.254.227]) by kanga.kvack.org (Postfix) with SMTP id 5EDC06B004D for ; Thu, 21 May 2009 09:30:49 -0400 (EDT) Received: from localhost (smtp.ultrahosting.com [127.0.0.1]) by smtp.ultrahosting.com (Postfix) with ESMTP id 4893982C6B6 for ; Thu, 21 May 2009 09:44:45 -0400 (EDT) Received: from smtp.ultrahosting.com ([74.213.175.254]) by localhost (smtp.ultrahosting.com [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id 4ONk+KU9Gr3K for ; Thu, 21 May 2009 09:44:45 -0400 (EDT) Received: from qirst.com (unknown [74.213.171.31]) by smtp.ultrahosting.com (Postfix) with ESMTP id 9502482C735 for ; Thu, 21 May 2009 09:44:40 -0400 (EDT) Date: Thu, 21 May 2009 09:31:08 -0400 (EDT) From: Christoph Lameter Subject: Re: [PATCH 4/4] zone_reclaim_mode is always 0 by default In-Reply-To: <20090521090549.63B5.A69D9226@jp.fujitsu.com> Message-ID: References: <20090519102003.4EAB.A69D9226@jp.fujitsu.com> <20090520140045.GA29447@sgi.com> <20090521090549.63B5.A69D9226@jp.fujitsu.com> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-linux-mm@kvack.org To: KOSAKI Motohiro Cc: Robin Holt , LKML , linux-mm , Andrew Morton , Rik van Riel List-ID: On Thu, 21 May 2009, KOSAKI Motohiro wrote: > I can't catch up your message. Can you post your patch? > Can you explain your sanity check? > > Now, I decide to remove "nr_online_nodes >= 4" condition. > Apache regression is really non-sense. Not sure what that means? Apache regresses with zone reclaim? My measurements when we introduced zone reclaim showed just the opposite because Apache would get node local memory and thus run faster. You can screw this up of course if you load the system so high that the apache processes are tossed around by the scheduler. Then the node local allocation may be worse than round robin because all the pages allocated by a process are now on one node if the scheduler moves the process to a remote node then all accesses are penalized. > > 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? -- 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