From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752152Ab2KPOzP (ORCPT ); Fri, 16 Nov 2012 09:55:15 -0500 Received: from cantor2.suse.de ([195.135.220.15]:45422 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751450Ab2KPOzL (ORCPT ); Fri, 16 Nov 2012 09:55:11 -0500 Date: Fri, 16 Nov 2012 15:55:08 +0100 From: Michal Hocko To: Kamezawa Hiroyuki Cc: Glauber Costa , Andrew Morton , linux-mm@kvack.org, linux-kernel@vger.kernel.org, Tejun Heo , Johannes Weiner , Christoph Lameter , Pekka Enberg Subject: Re: [PATCH 5/7] memcg: get rid of once-per-second cache shrinking for dead memcgs Message-ID: <20121116145508.GC2006@dhcp22.suse.cz> References: <1352948093-2315-1-git-send-email-glommer@parallels.com> <1352948093-2315-6-git-send-email-glommer@parallels.com> <50A4B8C8.6020202@jp.fujitsu.com> <50A4F289.1090807@parallels.com> <50A5CA16.7070603@jp.fujitsu.com> <50A5E73F.8030201@parallels.com> <50A5E997.6060002@jp.fujitsu.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <50A5E997.6060002@jp.fujitsu.com> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri 16-11-12 16:21:59, KAMEZAWA Hiroyuki wrote: > (2012/11/16 16:11), Glauber Costa wrote: > > On 11/16/2012 09:07 AM, Kamezawa Hiroyuki wrote: > >> (2012/11/15 22:47), Glauber Costa wrote: > >>> On 11/15/2012 01:41 PM, Kamezawa Hiroyuki wrote: > >>>> (2012/11/15 11:54), Glauber Costa wrote: > >>>>> The idea is to synchronously do it, leaving it up to the shrinking > >>>>> facilities in vmscan.c and/or others. Not actively retrying shrinking > >>>>> may leave the caches alive for more time, but it will remove the ugly > >>>>> wakeups. One would argue that if the caches have free objects but are > >>>>> not being shrunk, it is because we don't need that memory yet. > >>>>> > >>>>> Signed-off-by: Glauber Costa > >>>>> CC: Michal Hocko > >>>>> CC: Kamezawa Hiroyuki > >>>>> CC: Johannes Weiner > >>>>> CC: Andrew Morton > >>>> > >>>> I agree this patch but can we have a way to see the number of unaccounted > >>>> zombie cache usage for debugging ? > >>>> > >>>> Acked-by: KAMEZAWA Hiroyuki > >>>> > >>> Any particular interface in mind ? > >>> > >> > >> Hmm, it's debug interface and having cgroup file may be bad..... > >> If it can be seen in bytes or some, /proc/vmstat ? > >> > >> out_of_track_slabs xxxxxxx. hm ? > >> > > > > I particularly think that, being this a debug interface, it is also > > useful to have an indication of which caches are still in place. This is > > because the cache itself, is the best indication we have about the > > specific workload that may be keeping it in memory. > > > > I first thought debugfs could help us probing useful information out of > > it, but given all the abuse people inflicted in debugfs... maybe we > > could have a file in the root memcg with that information for all > > removed memcgs? If we do that, we can go further and list the memcgs > > that are pending due to memsw as well. memory.dangling_memcgs ? > > > > Hm, I'm ok with it... others ? What about memory.kmem.dangling_caches? -- Michal Hocko SUSE Labs From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from psmtp.com (na3sys010amx182.postini.com [74.125.245.182]) by kanga.kvack.org (Postfix) with SMTP id E17686B006C for ; Fri, 16 Nov 2012 09:55:11 -0500 (EST) Date: Fri, 16 Nov 2012 15:55:08 +0100 From: Michal Hocko Subject: Re: [PATCH 5/7] memcg: get rid of once-per-second cache shrinking for dead memcgs Message-ID: <20121116145508.GC2006@dhcp22.suse.cz> References: <1352948093-2315-1-git-send-email-glommer@parallels.com> <1352948093-2315-6-git-send-email-glommer@parallels.com> <50A4B8C8.6020202@jp.fujitsu.com> <50A4F289.1090807@parallels.com> <50A5CA16.7070603@jp.fujitsu.com> <50A5E73F.8030201@parallels.com> <50A5E997.6060002@jp.fujitsu.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <50A5E997.6060002@jp.fujitsu.com> Sender: owner-linux-mm@kvack.org List-ID: To: Kamezawa Hiroyuki Cc: Glauber Costa , Andrew Morton , linux-mm@kvack.org, linux-kernel@vger.kernel.org, Tejun Heo , Johannes Weiner , Christoph Lameter , Pekka Enberg On Fri 16-11-12 16:21:59, KAMEZAWA Hiroyuki wrote: > (2012/11/16 16:11), Glauber Costa wrote: > > On 11/16/2012 09:07 AM, Kamezawa Hiroyuki wrote: > >> (2012/11/15 22:47), Glauber Costa wrote: > >>> On 11/15/2012 01:41 PM, Kamezawa Hiroyuki wrote: > >>>> (2012/11/15 11:54), Glauber Costa wrote: > >>>>> The idea is to synchronously do it, leaving it up to the shrinking > >>>>> facilities in vmscan.c and/or others. Not actively retrying shrinking > >>>>> may leave the caches alive for more time, but it will remove the ugly > >>>>> wakeups. One would argue that if the caches have free objects but are > >>>>> not being shrunk, it is because we don't need that memory yet. > >>>>> > >>>>> Signed-off-by: Glauber Costa > >>>>> CC: Michal Hocko > >>>>> CC: Kamezawa Hiroyuki > >>>>> CC: Johannes Weiner > >>>>> CC: Andrew Morton > >>>> > >>>> I agree this patch but can we have a way to see the number of unaccounted > >>>> zombie cache usage for debugging ? > >>>> > >>>> Acked-by: KAMEZAWA Hiroyuki > >>>> > >>> Any particular interface in mind ? > >>> > >> > >> Hmm, it's debug interface and having cgroup file may be bad..... > >> If it can be seen in bytes or some, /proc/vmstat ? > >> > >> out_of_track_slabs xxxxxxx. hm ? > >> > > > > I particularly think that, being this a debug interface, it is also > > useful to have an indication of which caches are still in place. This is > > because the cache itself, is the best indication we have about the > > specific workload that may be keeping it in memory. > > > > I first thought debugfs could help us probing useful information out of > > it, but given all the abuse people inflicted in debugfs... maybe we > > could have a file in the root memcg with that information for all > > removed memcgs? If we do that, we can go further and list the memcgs > > that are pending due to memsw as well. memory.dangling_memcgs ? > > > > Hm, I'm ok with it... others ? What about memory.kmem.dangling_caches? -- Michal Hocko SUSE Labs -- 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