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 710166B005C for ; Mon, 8 Jun 2009 09:29:43 -0400 (EDT) Message-ID: <4A2D24B0.4080301@redhat.com> Date: Mon, 08 Jun 2009 10:48:16 -0400 From: Rik van Riel MIME-Version: 1.0 Subject: Re: [PATCH 1/3] Reintroduce zone_reclaim_interval for when zone_reclaim() scans and fails to avoid CPU spinning at 100% on NUMA References: <1244466090-10711-1-git-send-email-mel@csn.ul.ie> <1244466090-10711-2-git-send-email-mel@csn.ul.ie> <4A2D129D.3020309@redhat.com> <20090608135433.GD15070@csn.ul.ie> In-Reply-To: <20090608135433.GD15070@csn.ul.ie> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org To: Mel Gorman Cc: KOSAKI Motohiro , Christoph Lameter , yanmin.zhang@intel.com, Wu Fengguang , linuxram@us.ibm.com, linux-mm , LKML List-ID: Mel Gorman wrote: > On Mon, Jun 08, 2009 at 09:31:09AM -0400, Rik van Riel wrote: >> Mel Gorman wrote: >> >>> The scanning occurs because zone_reclaim() cannot tell >>> in advance the scan is pointless because the counters do not distinguish >>> between pagecache pages backed by disk and by RAM. >> Yes it can. Since 2.6.27, filesystem backed and swap/ram backed >> pages have been living on separate LRU lists. > > Yes, they're on separate LRU lists but they are not the only pages on those > lists. The tmpfs pages are mixed in together with anonymous pages so we > cannot use NR_*_ANON. > > Look at patch 2 and where I introduced; I have to admit I did not read patches 2 and 3 before replying to the (strange looking, at the time) text above patch 1. With that logic from patch 2 in place, patch 1 makes perfect sense. Acked-by: Rik van Riel -- All rights reversed. -- 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