From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail144.messagelabs.com (mail144.messagelabs.com [216.82.254.51]) by kanga.kvack.org (Postfix) with SMTP id D57516B01F2 for ; Tue, 17 Aug 2010 23:07:26 -0400 (EDT) Received: from m5.gw.fujitsu.co.jp ([10.0.50.75]) by fgwmail5.fujitsu.co.jp (Fujitsu Gateway) with ESMTP id o7I37OHc031858 for (envelope-from kamezawa.hiroyu@jp.fujitsu.com); Wed, 18 Aug 2010 12:07:24 +0900 Received: from smail (m5 [127.0.0.1]) by outgoing.m5.gw.fujitsu.co.jp (Postfix) with ESMTP id AEF6F45DE4F for ; Wed, 18 Aug 2010 12:07:23 +0900 (JST) Received: from s5.gw.fujitsu.co.jp (s5.gw.fujitsu.co.jp [10.0.50.95]) by m5.gw.fujitsu.co.jp (Postfix) with ESMTP id 7225D45DE51 for ; Wed, 18 Aug 2010 12:07:23 +0900 (JST) Received: from s5.gw.fujitsu.co.jp (localhost.localdomain [127.0.0.1]) by s5.gw.fujitsu.co.jp (Postfix) with ESMTP id 47355E18001 for ; Wed, 18 Aug 2010 12:07:23 +0900 (JST) Received: from ml13.s.css.fujitsu.com (ml13.s.css.fujitsu.com [10.249.87.103]) by s5.gw.fujitsu.co.jp (Postfix) with ESMTP id BCBEEE08001 for ; Wed, 18 Aug 2010 12:07:22 +0900 (JST) Date: Wed, 18 Aug 2010 12:02:32 +0900 From: KAMEZAWA Hiroyuki Subject: Re: [PATCH 3/3] mm: page allocator: Drain per-cpu lists after direct reclaim allocation fails Message-Id: <20100818120232.a9dc128e.kamezawa.hiroyu@jp.fujitsu.com> In-Reply-To: <1281951733-29466-4-git-send-email-mel@csn.ul.ie> References: <1281951733-29466-1-git-send-email-mel@csn.ul.ie> <1281951733-29466-4-git-send-email-mel@csn.ul.ie> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org To: Mel Gorman Cc: linux-mm@kvack.org, Rik van Riel , Nick Piggin , Johannes Weiner , KOSAKI Motohiro List-ID: On Mon, 16 Aug 2010 10:42:13 +0100 Mel Gorman wrote: > When under significant memory pressure, a process enters direct reclaim > and immediately afterwards tries to allocate a page. If it fails and no > further progress is made, it's possible the system will go OOM. However, > on systems with large amounts of memory, it's possible that a significant > number of pages are on per-cpu lists and inaccessible to the calling > process. This leads to a process entering direct reclaim more often than > it should increasing the pressure on the system and compounding the problem. > > This patch notes that if direct reclaim is making progress but > allocations are still failing that the system is already under heavy > pressure. In this case, it drains the per-cpu lists and tries the > allocation a second time before continuing. > > Signed-off-by: Mel Gorman Reviewed-by: KAMEZAWA Hiroyuki -- 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