From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail191.messagelabs.com (mail191.messagelabs.com [216.82.242.19]) by kanga.kvack.org (Postfix) with SMTP id BF75B6B009E for ; Wed, 10 Jun 2009 02:42:46 -0400 (EDT) Received: from m6.gw.fujitsu.co.jp ([10.0.50.76]) by fgwmail6.fujitsu.co.jp (Fujitsu Gateway) with ESMTP id n5A6i5UF017652 for (envelope-from kosaki.motohiro@jp.fujitsu.com); Wed, 10 Jun 2009 15:44:05 +0900 Received: from smail (m6 [127.0.0.1]) by outgoing.m6.gw.fujitsu.co.jp (Postfix) with ESMTP id 0BD1645DD72 for ; Wed, 10 Jun 2009 15:44:05 +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 C990645DE50 for ; Wed, 10 Jun 2009 15:44:04 +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 B5D501DB8043 for ; Wed, 10 Jun 2009 15:44:04 +0900 (JST) Received: from m107.s.css.fujitsu.com (m107.s.css.fujitsu.com [10.249.87.107]) by s6.gw.fujitsu.co.jp (Postfix) with ESMTP id 489331DB8044 for ; Wed, 10 Jun 2009 15:44:04 +0900 (JST) From: KOSAKI Motohiro Subject: Re: [PATCH 1/3] Reintroduce zone_reclaim_interval for when zone_reclaim() scans and fails to avoid CPU spinning at 100% on NUMA In-Reply-To: <20090609222301.8da002ae.akpm@linux-foundation.org> References: <20090608151151.GI15070@csn.ul.ie> <20090609222301.8da002ae.akpm@linux-foundation.org> Message-Id: <20090610154016.DDC3.A69D9226@jp.fujitsu.com> MIME-Version: 1.0 Content-Type: text/plain; charset="US-ASCII" Content-Transfer-Encoding: 7bit Date: Wed, 10 Jun 2009 15:44:03 +0900 (JST) Sender: owner-linux-mm@kvack.org To: Andrew Morton Cc: kosaki.motohiro@jp.fujitsu.com, Mel Gorman , Christoph Lameter , Rik van Riel , yanmin.zhang@intel.com, Wu Fengguang , linuxram@us.ibm.com, linux-mm , LKML List-ID: Hi > On Mon, 8 Jun 2009 16:11:51 +0100 Mel Gorman wrote: > > > On Mon, Jun 08, 2009 at 10:55:55AM -0400, Christoph Lameter wrote: > > > On Mon, 8 Jun 2009, Mel Gorman wrote: > > > > > > > > The tmpfs pages are unreclaimable and therefore should not be on the anon > > > > > lru. > > > > > > > > > > > > > tmpfs pages can be swap-backed so can be reclaimable. Regardless of what > > > > list they are on, we still need to know how many of them there are if > > > > this patch is to be avoided. > > > > > > If they are reclaimable then why does it matter? They can be pushed out if > > > you configure zone reclaim to be that aggressive. > > > > > > > Because they are reclaimable by kswapd or normal direct reclaim but *not* > > reclaimable by zone_reclaim() if the zone_reclaim_mode is not configured > > appropriately. > > Ah. (zone_reclaim_mode & RECLAIM_SWAP) == 0. That was important info. > > Couldn't the lack of RECLAIM_WRITE cause a similar problem? Old kernel can makes easily. but currenly we have proper dirty page limit. Thus all pages can't become dirty and zone-reclaim can found cleaner page. In the other hand, plenty tmpfs pages can be mede easily. -- 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