Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751297Ab2KPHMR (ORCPT ); Fri, 16 Nov 2012 02:12:17 -0500 Received: from mx2.parallels.com ([64.131.90.16]:37088 "EHLO mx2.parallels.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750853Ab2KPHMQ (ORCPT ); Fri, 16 Nov 2012 02:12:16 -0500 Message-ID: <50A5E73F.8030201@parallels.com> Date: Fri, 16 Nov 2012 11:11:59 +0400 From: Glauber Costa User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:16.0) Gecko/20121029 Thunderbird/16.0.2 MIME-Version: 1.0 To: Kamezawa Hiroyuki CC: Andrew Morton , , , Tejun Heo , Michal Hocko , Johannes Weiner , Christoph Lameter , Pekka Enberg Subject: Re: [PATCH 5/7] memcg: get rid of once-per-second cache shrinking for dead memcgs 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> In-Reply-To: <50A5CA16.7070603@jp.fujitsu.com> Content-Type: text/plain; charset="ISO-2022-JP" Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2061 Lines: 47 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 ? -- 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/