From mboxrd@z Thu Jan 1 00:00:00 1970 Date: Thu, 26 Apr 2007 09:31:12 +0900 From: KAMEZAWA Hiroyuki Subject: Re: [RFC][PATCH] syctl for selecting global zonelist[] order Message-Id: <20070426093112.ec2ecb00.kamezawa.hiroyu@jp.fujitsu.com> In-Reply-To: References: <20070425121946.9eb27a79.kamezawa.hiroyu@jp.fujitsu.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: Christoph Lameter Cc: linux-kernel@vger.kernel.org, linux-mm@kvack.org, y-goto@jp.fujitsu.com List-ID: On Wed, 25 Apr 2007 12:17:15 -0700 (PDT) Christoph Lameter wrote: > On Wed, 25 Apr 2007, KAMEZAWA Hiroyuki wrote: > > > Make zonelist policy selectable from sysctl. > > > > Assume 2 node NUMA, only node(0) has ZONE_DMA (ZONE_DMA32). > > > > In this case, default (node0's) zonelist order is > > > > Node(0)'s NORMAL -> Node(0)'s DMA -> Node(1)"s NORMAL. > > > > This means Node(0)'s DMA is used before Node(1)'s NORMAL. > > So a IA64 platform with i386 sicknesses? And pretty bad case of it since I > assume that the memory sizes per node are equal. Your solution of taking > 4G off node 0 and then going to node 1 first must hurt some > processes running on node 0. I think so, too. It is because I made this as selectable option. > Whatever you do the memory balance between the two nodes is making > the system behave in an unsymmetric way. > > In some server, some application uses large memory allcation. > > This exhaust memory in the above order. > > Could we add a boot time option instead that changes the zonelist build > behavior? Maybe an arch hook that can deal with it? > Yes, it' in my plan. I'll add boot option support. Thanks, -Kame -- 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