From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail203.messagelabs.com (mail203.messagelabs.com [216.82.254.243]) by kanga.kvack.org (Postfix) with SMTP id 6072A60021B for ; Wed, 30 Dec 2009 08:13:49 -0500 (EST) Date: Wed, 30 Dec 2009 22:13:42 +0900 (JST) From: KOSAKI Motohiro Subject: Re: [PATCH 3/4] vmstat: add anon_scan_ratio field to zoneinfo In-Reply-To: <20091229140825.GQ3601@balbir.in.ibm.com> References: <20091228164816.A68D.A69D9226@jp.fujitsu.com> <20091229140825.GQ3601@balbir.in.ibm.com> Message-Id: <20091230220704.1A16.A69D9226@jp.fujitsu.com> MIME-Version: 1.0 Content-Type: text/plain; charset="US-ASCII" Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org To: balbir@linux.vnet.ibm.com Cc: kosaki.motohiro@jp.fujitsu.com, LKML , linux-mm , Andrew Morton , Mel Gorman , KAMEZAWA Hiroyuki List-ID: > * KOSAKI Motohiro [2009-12-28 16:48:51]: > > > Vmscan folks was asked "why does my system makes so much swap-out?" > > in lkml at several times. > > At that time, I made the debug patch to show recent_anon_{scanned/rorated} > > parameter at least three times. > > > > Thus, its parameter should be showed on /proc/zoneinfo. It help > > vmscan folks debugging. > > > > Hmmm.. I think this should come under DEBUG_VM, a lot of tools use > /proc/zoneinfo, the additional overhead may be high.. no? Also, > I would recommend adding the additional details to the end, so > as to not break existing tools (specifically dump line # based > tools). Thanks, I have three answer. 1) I really hope to don't enclose DEBUG_VM. otherwise my harm doesn't solve. 2) but your performance worry is fair enough. I plan to remove to grab zone->lru_lock in reading /proc/zoneinfo. 3) append new line doesn't break existing tools. because zoneinfo show vmstat and we often append new vmstat in past years. but I haven't seen zoneinfo breakage bug report. because zoneinfo file show multiple zone information, then nobody access it by line number. -- 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