From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail190.messagelabs.com (mail190.messagelabs.com [216.82.249.51]) by kanga.kvack.org (Postfix) with SMTP id B5A326B006A for ; Thu, 7 Oct 2010 21:53:24 -0400 (EDT) Received: from m6.gw.fujitsu.co.jp ([10.0.50.76]) by fgwmail5.fujitsu.co.jp (Fujitsu Gateway) with ESMTP id o981mRLW007104 for (envelope-from kosaki.motohiro@jp.fujitsu.com); Fri, 8 Oct 2010 10:48:28 +0900 Received: from smail (m6 [127.0.0.1]) by outgoing.m6.gw.fujitsu.co.jp (Postfix) with ESMTP id 9523545DE51 for ; Fri, 8 Oct 2010 10:48:27 +0900 (JST) Received: from s6.gw.fujitsu.co.jp (s6.gw.fujitsu.co.jp [10.0.50.96]) by m6.gw.fujitsu.co.jp (Postfix) with ESMTP id 72C8D45DE50 for ; Fri, 8 Oct 2010 10:48:27 +0900 (JST) Received: from s6.gw.fujitsu.co.jp (localhost.localdomain [127.0.0.1]) by s6.gw.fujitsu.co.jp (Postfix) with ESMTP id 53596E38005 for ; Fri, 8 Oct 2010 10:48:27 +0900 (JST) Received: from m108.s.css.fujitsu.com (m108.s.css.fujitsu.com [10.249.87.108]) by s6.gw.fujitsu.co.jp (Postfix) with ESMTP id 051C2E38002 for ; Fri, 8 Oct 2010 10:48:27 +0900 (JST) From: KOSAKI Motohiro Subject: [resend][PATCH] mm: increase RECLAIM_DISTANCE to 30 Message-Id: <20101008104852.803E.A69D9226@jp.fujitsu.com> MIME-Version: 1.0 Content-Type: text/plain; charset="US-ASCII" Content-Transfer-Encoding: 7bit Date: Fri, 8 Oct 2010 10:48:26 +0900 (JST) Sender: owner-linux-mm@kvack.org To: Christoph Lameter , Mel Gorman , Rob Mueller , linux-kernel@vger.kernel.org, Bron Gondwana , linux-mm , David Rientjes Cc: kosaki.motohiro@jp.fujitsu.com List-ID: Recently, Robert Mueller reported zone_reclaim_mode doesn't work properly on his new NUMA server (Dual Xeon E5520 + Intel S5520UR MB). He is using Cyrus IMAPd and it's built on a very traditional single-process model. * a master process which reads config files and manages the other process * multiple imapd processes, one per connection * multiple pop3d processes, one per connection * multiple lmtpd processes, one per connection * periodical "cleanup" processes. Then, there are thousands of independent processes. The problem is, recent Intel motherboard turn on zone_reclaim_mode by default and traditional prefork model software don't work fine on it. Unfortunatelly, Such model is still typical one even though 21th century. We can't ignore them. This patch raise zone_reclaim_mode threshold to 30. 30 don't have specific meaning. but 20 mean one-hop QPI/Hypertransport and such relatively cheap 2-4 socket machine are often used for tradiotional server as above. The intention is, their machine don't use zone_reclaim_mode. Note: ia64 and Power have arch specific RECLAIM_DISTANCE definition. then this patch doesn't change such high-end NUMA machine behavior. Cc: Mel Gorman Cc: Bron Gondwana Cc: Robert Mueller Acked-by: Christoph Lameter Acked-by: David Rientjes Signed-off-by: KOSAKI Motohiro --- include/linux/topology.h | 2 +- 1 files changed, 1 insertions(+), 1 deletions(-) diff --git a/include/linux/topology.h b/include/linux/topology.h index 64e084f..bfbec49 100644 --- a/include/linux/topology.h +++ b/include/linux/topology.h @@ -60,7 +60,7 @@ int arch_update_cpu_topology(void); * (in whatever arch specific measurement units returned by node_distance()) * then switch on zone reclaim on boot. */ -#define RECLAIM_DISTANCE 20 +#define RECLAIM_DISTANCE 30 #endif #ifndef PENALTY_FOR_NODE_WITH_CPUS #define PENALTY_FOR_NODE_WITH_CPUS (1) -- 1.6.5.2 -- 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