From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from psmtp.com (na3sys010amx145.postini.com [74.125.245.145]) by kanga.kvack.org (Postfix) with SMTP id 9508A6B0032 for ; Wed, 15 May 2013 11:26:40 -0400 (EDT) Message-ID: <5193A95E.70205@parallels.com> Date: Wed, 15 May 2013 19:27:26 +0400 From: Glauber Costa MIME-Version: 1.0 Subject: Re: [PATCH v6 12/31] fs: convert inode and dentry shrinking to be node aware References: <1368382432-25462-1-git-send-email-glommer@openvz.org> <1368382432-25462-13-git-send-email-glommer@openvz.org> <20130514095200.GI29466@dastard> In-Reply-To: <20130514095200.GI29466@dastard> Content-Type: text/plain; charset="ISO-8859-1" Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org List-ID: To: Dave Chinner Cc: Glauber Costa , linux-mm@kvack.org, cgroups@vger.kernel.org, Andrew Morton , Greg Thelen , kamezawa.hiroyu@jp.fujitsu.com, Michal Hocko , Johannes Weiner , linux-fsdevel@vger.kernel.org, Dave Chinner On 05/14/2013 01:52 PM, Dave Chinner wrote: > kswapd0-632 1210443.469309: mm_shrink_slab_start: cache items 600456 delta 1363 total_scan 300228 > kswapd3-635 1210443.510311: mm_shrink_slab_start: cache items 514885 delta 1250 total_scan 101025 > kswapd1-633 1210443.517440: mm_shrink_slab_start: cache items 613824 delta 1357 total_scan 97727 > kswapd2-634 1210443.527026: mm_shrink_slab_start: cache items 568610 delta 1331 total_scan 259185 > kswapd3-635 1210443.573165: mm_shrink_slab_start: cache items 486408 delta 1277 total_scan 243204 > kswapd1-633 1210443.697012: mm_shrink_slab_start: cache items 550827 delta 1224 total_scan 82231 > > in the space of 230ms, I can see why the caches are getting > completely emptied. kswapds are making multiple, large scale scan > passes on the caches. Looks like our problem is an impedence > mismatch: global windup counter, per-node cache scan calculations. > > So, that's the mess we really need to cleaning up before going much > further with this patchset. We need stable behaviour from the > shrinkers - I'll look into this a bit deeper tomorrow. That doesn't totally make sense to me. Both our scan and count functions will be per-node now. This means we will always try to keep ourselves within reasonable maximums on a per-node basis as well. -- 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