From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail137.messagelabs.com (mail137.messagelabs.com [216.82.249.19]) by kanga.kvack.org (Postfix) with SMTP id C6DA76B0078 for ; Tue, 7 Sep 2010 23:14:33 -0400 (EDT) Received: from m2.gw.fujitsu.co.jp ([10.0.50.72]) by fgwmail7.fujitsu.co.jp (Fujitsu Gateway) with ESMTP id o883EVZN014774 for (envelope-from kosaki.motohiro@jp.fujitsu.com); Wed, 8 Sep 2010 12:14:31 +0900 Received: from smail (m2 [127.0.0.1]) by outgoing.m2.gw.fujitsu.co.jp (Postfix) with ESMTP id 6480645DE55 for ; Wed, 8 Sep 2010 12:14:31 +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 4399A45DE4F for ; Wed, 8 Sep 2010 12:14:31 +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 23BC11DB803C for ; Wed, 8 Sep 2010 12:14:31 +0900 (JST) Received: from m108.s.css.fujitsu.com (m108.s.css.fujitsu.com [10.249.87.108]) by s2.gw.fujitsu.co.jp (Postfix) with ESMTP id DAFD61DB803A for ; Wed, 8 Sep 2010 12:14:30 +0900 (JST) From: KOSAKI Motohiro Subject: Re: [PATCH 0/9] Reduce latencies and improve overall reclaim efficiency v1 In-Reply-To: <1283770053-18833-1-git-send-email-mel@csn.ul.ie> References: <1283770053-18833-1-git-send-email-mel@csn.ul.ie> Message-Id: <20100908115807.C916.A69D9226@jp.fujitsu.com> MIME-Version: 1.0 Content-Type: text/plain; charset="US-ASCII" Content-Transfer-Encoding: 7bit Date: Wed, 8 Sep 2010 12:14:29 +0900 (JST) Sender: owner-linux-mm@kvack.org To: Mel Gorman Cc: kosaki.motohiro@jp.fujitsu.com, linux-mm@kvack.org, linux-fsdevel@vger.kernel.org, Linux Kernel List , Rik van Riel , Johannes Weiner , Minchan Kim , Wu Fengguang , Andrea Arcangeli , KAMEZAWA Hiroyuki , Dave Chinner , Chris Mason , Christoph Hellwig , Andrew Morton List-ID: > There have been numerous reports of stalls that pointed at the problem being > somewhere in the VM. There are multiple roots to the problems which means > dealing with any of the root problems in isolation is tricky to justify on > their own and they would still need integration testing. This patch series > gathers together three different patch sets which in combination should > tackle some of the root causes of latency problems being reported. > > The first patch improves vmscan latency by tracking when pages get reclaimed > by shrink_inactive_list. For this series, the most important results is > being able to calculate the scanning/reclaim ratio as a measure of the > amount of work being done by page reclaim. > > Patches 2 and 3 account for the time spent in congestion_wait() and avoids > calling going to sleep on congestion when it is unnecessary. This is expected > to reduce stalls in situations where the system is under memory pressure > but not due to congestion. > > Patches 4-8 were originally developed by Kosaki Motohiro but reworked for > this series. It has been noted that lumpy reclaim is far too aggressive and > trashes the system somewhat. As SLUB uses high-order allocations, a large > cost incurred by lumpy reclaim will be noticeable. It was also reported > during transparent hugepage support testing that lumpy reclaim was trashing > the system and these patches should mitigate that problem without disabling > lumpy reclaim. Wow, I'm sorry my lazyness bother you. I'll join to test this patch series ASAP and take a feedback soon. -- 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