Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751013AbVJGINM (ORCPT ); Fri, 7 Oct 2005 04:13:12 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751284AbVJGINM (ORCPT ); Fri, 7 Oct 2005 04:13:12 -0400 Received: from e4.ny.us.ibm.com ([32.97.182.144]:4546 "EHLO e4.ny.us.ibm.com") by vger.kernel.org with ESMTP id S1751013AbVJGINK (ORCPT ); Fri, 7 Oct 2005 04:13:10 -0400 Date: Fri, 7 Oct 2005 13:42:49 +0530 From: Bharata B Rao To: Marcelo Tosatti Cc: "Theodore Ts'o" , Dipankar Sarma , linux-mm@kvack.org, linux-kernel@vger.kernel.org Subject: Re: shrinkable cache statistics [was Re: VM balancing issues on 2.6.13: dentry cache not getting shrunk enough] Message-ID: <20051007081249.GA3781@in.ibm.com> Reply-To: bharata@in.ibm.com References: <20050911120045.GA4477@in.ibm.com> <20050912031636.GB16758@thunk.org> <20050913084752.GC4474@in.ibm.com> <20050914230843.GA11748@dmt.cnet> <20050915093945.GD3869@in.ibm.com> <20050915132910.GA6806@dmt.cnet> <20051002163229.GB5190@in.ibm.com> <20051002200640.GB9865@xeon.cnet> <20051004133635.GA23575@in.ibm.com> <20051005212551.GA10057@logos.cnet> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20051005212551.GA10057@logos.cnet> User-Agent: Mutt/1.4.2.1i Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2722 Lines: 57 On Wed, Oct 05, 2005 at 06:25:51PM -0300, Marcelo Tosatti wrote: > Hi Bharata, > > On Tue, Oct 04, 2005 at 07:06:35PM +0530, Bharata B Rao wrote: > > Marcelo, > > > > Here's my next attempt in breaking the "slabs_scanned" from /proc/vmstat > > into meaningful per cache statistics. Now I have the statistics counters > > as percpu. [an issue remaining is that there are more than one cache as > > part of mbcache and they all have a common shrinker routine and I am > > displaying the collective shrinker stats info on each of them in > > /proc/slabinfo ==> some kind of duplication] > > Looks good to me! IMO it should be a candidate for -mm/mainline. > > Nothing useful to suggest on the mbcache issue... sorry. Thanks Marcelo for reviewing. > > > > [root@llm09 bharata]# grep shrinker /proc/slabinfo > > # name : tunables : slabdata : shrinker stat > > ext3_xattr 0 0 48 78 1 : tunables 120 60 8 : slabdata 0 0 0 : shrinker stat 0 0 > > dquot 0 0 160 24 1 : tunables 120 60 8 : slabdata 0 0 0 : shrinker stat 0 0 > > inode_cache 1301 1390 400 10 1 : tunables 54 27 8 : slabdata 139 139 0 : shrinker stat 682752 681900 > > dentry_cache 82110 114452 152 26 1 : tunables 120 60 8 : slabdata 4402 4402 0 : shrinker stat 1557760 760100 > > > > [root@llm09 bharata]# grep slabs_scanned /proc/vmstat > > slabs_scanned 2240512 > > > > [root@llm09 bharata]# cat /proc/sys/fs/dentry-state > > 82046 75369 45 0 3599 0 > > [The order of dentry-state o/p is like this: > > total dentries in dentry hash list, total dentries in lru list, age limit, > > want_pages, inuse dentries in lru list, dummy] > > > > So, we can see that with low memory pressure, even though the > > shrinker runs on dcache repeatedly, not many dentries are freed > > by dcache. And dcache lru list still has huge number of free > > dentries. > > The success/attempt ratio is about 1/2, which seems alright? > Hmm... when compared to inode_cache, I felt dcache shrinker wasn't doing a good job. Anyway I will analyze further to see if things can be made better with the existing shrinker. Regards, Bharata. - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/