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 3CECF6B0088 for ; Thu, 9 Dec 2010 20:12:17 -0500 (EST) Received: from m2.gw.fujitsu.co.jp ([10.0.50.72]) by fgwmail5.fujitsu.co.jp (Fujitsu Gateway) with ESMTP id oBA1CBxB032267 for (envelope-from kamezawa.hiroyu@jp.fujitsu.com); Fri, 10 Dec 2010 10:12:12 +0900 Received: from smail (m2 [127.0.0.1]) by outgoing.m2.gw.fujitsu.co.jp (Postfix) with ESMTP id CBF0845DE73 for ; Fri, 10 Dec 2010 10:12:11 +0900 (JST) Received: from s2.gw.fujitsu.co.jp (s2.gw.fujitsu.co.jp [10.0.50.92]) by m2.gw.fujitsu.co.jp (Postfix) with ESMTP id B4CCB45DE68 for ; Fri, 10 Dec 2010 10:12:11 +0900 (JST) Received: from s2.gw.fujitsu.co.jp (localhost.localdomain [127.0.0.1]) by s2.gw.fujitsu.co.jp (Postfix) with ESMTP id A6A221DB8038 for ; Fri, 10 Dec 2010 10:12:11 +0900 (JST) Received: from m107.s.css.fujitsu.com (m107.s.css.fujitsu.com [10.249.87.107]) by s2.gw.fujitsu.co.jp (Postfix) with ESMTP id 727E51DB803B for ; Fri, 10 Dec 2010 10:12:11 +0900 (JST) Date: Fri, 10 Dec 2010 10:06:28 +0900 From: KAMEZAWA Hiroyuki Subject: Re: [PATCH 1/6] mm: kswapd: Stop high-order balancing when any suitable zone is balanced Message-Id: <20101210100628.bd890c77.kamezawa.hiroyu@jp.fujitsu.com> In-Reply-To: <1291893500-12342-2-git-send-email-mel@csn.ul.ie> References: <1291893500-12342-1-git-send-email-mel@csn.ul.ie> <1291893500-12342-2-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: Simon Kirby , KOSAKI Motohiro , Shaohua Li , Dave Hansen , Johannes Weiner , Andrew Morton , linux-mm , linux-kernel List-ID: On Thu, 9 Dec 2010 11:18:15 +0000 Mel Gorman wrote: > When the allocator enters its slow path, kswapd is woken up to balance the > node. It continues working until all zones within the node are balanced. For > order-0 allocations, this makes perfect sense but for higher orders it can > have unintended side-effects. If the zone sizes are imbalanced, kswapd may > reclaim heavily within a smaller zone discarding an excessive number of > pages. The user-visible behaviour is that kswapd is awake and reclaiming > even though plenty of pages are free from a suitable zone. > > This patch alters the "balance" logic for high-order reclaim allowing kswapd > to stop if any suitable zone becomes balanced to reduce the number of pages > it reclaims from other zones. kswapd still tries to ensure that order-0 > watermarks for all zones are met before sleeping. > > 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/ . Fight unfair telecom policy in Canada: sign http://dissolvethecrtc.ca/ Don't email: email@kvack.org