From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752548Ab2KPPuy (ORCPT ); Fri, 16 Nov 2012 10:50:54 -0500 Received: from mx2.parallels.com ([64.131.90.16]:59117 "EHLO mx2.parallels.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752203Ab2KPPuy (ORCPT ); Fri, 16 Nov 2012 10:50:54 -0500 Message-ID: <50A660D1.7020001@parallels.com> Date: Fri, 16 Nov 2012 19:50:41 +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: Michal Hocko CC: Kamezawa Hiroyuki , Andrew Morton , , , 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 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> <20121116145508.GC2006@dhcp22.suse.cz> In-Reply-To: <20121116145508.GC2006@dhcp22.suse.cz> Content-Type: text/plain; charset="ISO-8859-1" Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 11/16/2012 06:55 PM, Michal Hocko wrote: > 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? > If that is what it does, sure. But as I said, kmem is not the only thing that can keep caches in memory. If we're going for this, maybe we should be more comprehensive and show it all. From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from psmtp.com (na3sys010amx137.postini.com [74.125.245.137]) by kanga.kvack.org (Postfix) with SMTP id 0021F6B0078 for ; Fri, 16 Nov 2012 10:50:57 -0500 (EST) Message-ID: <50A660D1.7020001@parallels.com> Date: Fri, 16 Nov 2012 19:50:41 +0400 From: Glauber Costa MIME-Version: 1.0 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> <50A5E73F.8030201@parallels.com> <50A5E997.6060002@jp.fujitsu.com> <20121116145508.GC2006@dhcp22.suse.cz> In-Reply-To: <20121116145508.GC2006@dhcp22.suse.cz> Content-Type: text/plain; charset="ISO-8859-1" Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org List-ID: To: Michal Hocko Cc: Kamezawa Hiroyuki , Andrew Morton , linux-mm@kvack.org, linux-kernel@vger.kernel.org, Tejun Heo , Johannes Weiner , Christoph Lameter , Pekka Enberg On 11/16/2012 06:55 PM, Michal Hocko wrote: > 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? > If that is what it does, sure. But as I said, kmem is not the only thing that can keep caches in memory. If we're going for this, maybe we should be more comprehensive and show it all. -- 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