Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751257Ab1C1E3M (ORCPT ); Mon, 28 Mar 2011 00:29:12 -0400 Received: from TYO202.gate.nec.co.jp ([202.32.8.206]:40790 "EHLO tyo202.gate.nec.co.jp" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750788Ab1C1E3K (ORCPT ); Mon, 28 Mar 2011 00:29:10 -0400 Date: Mon, 28 Mar 2011 13:25:50 +0900 From: Daisuke Nishimura To: KAMEZAWA Hiroyuki Cc: Michal Hocko , Andrew Morton , linux-mm@kvack.org, LKML , Daisuke Nishimura Subject: [PATCH] memcg: update documentation to describe usage_in_bytes Message-Id: <20110328132550.08be4389.nishimura@mxp.nes.nec.co.jp> In-Reply-To: <20110328085508.c236e929.nishimura@mxp.nes.nec.co.jp> References: <20110318152532.GB18450@tiehlicka.suse.cz> <20110321093419.GA26047@tiehlicka.suse.cz> <20110321102420.GB26047@tiehlicka.suse.cz> <20110322091014.27677ab3.kamezawa.hiroyu@jp.fujitsu.com> <20110322104723.fd81dddc.nishimura@mxp.nes.nec.co.jp> <20110322073150.GA12940@tiehlicka.suse.cz> <20110323092708.021d555d.nishimura@mxp.nes.nec.co.jp> <20110323133517.de33d624.kamezawa.hiroyu@jp.fujitsu.com> <20110328085508.c236e929.nishimura@mxp.nes.nec.co.jp> Organization: NEC Soft, Ltd. X-Mailer: Sylpheed 3.1.0 (GTK+ 2.10.14; i686-pc-mingw32) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2854 Lines: 70 On Mon, 28 Mar 2011 08:55:08 +0900 Daisuke Nishimura wrote: > > > Considering more, without these files, we cannot know the actual usage of > > > a res_counter, although we set a limit to a res_counter. So, I want to keep > > > these files. > > > > > > If no-one have any objections, I'll prepare a patch to update the documentation. > > > > > > > please. > > > I'm sorry for my late response. I've been out of office because of a cold. > I'll prepare the patch later. > How about this ? === From: Daisuke Nishimura Update the meaning of *.usage_in_bytes. They doesn't show the actual usage of RSS+Cache(+Swap). They show the res_counter->usage for memory and memory+swap. Signed-off-by: Daisuke Nishimura --- Documentation/cgroups/memory.txt | 16 ++++++++++++++-- 1 files changed, 14 insertions(+), 2 deletions(-) diff --git a/Documentation/cgroups/memory.txt b/Documentation/cgroups/memory.txt index 7781857..ab7d4c1 100644 --- a/Documentation/cgroups/memory.txt +++ b/Documentation/cgroups/memory.txt @@ -52,8 +52,10 @@ Brief summary of control files. tasks # attach a task(thread) and show list of threads cgroup.procs # show list of processes cgroup.event_control # an interface for event_fd() - memory.usage_in_bytes # show current memory(RSS+Cache) usage. - memory.memsw.usage_in_bytes # show current memory+Swap usage + memory.usage_in_bytes # show current res_counter usage for memory + (See 5.5 for details) + memory.memsw.usage_in_bytes # show current res_counter usage for memory+Swap + (See 5.5 for details) memory.limit_in_bytes # set/show limit of memory usage memory.memsw.limit_in_bytes # set/show limit of memory+Swap usage memory.failcnt # show the number of memory usage hits limits @@ -453,6 +455,16 @@ memory under it will be reclaimed. You can reset failcnt by writing 0 to failcnt file. # echo 0 > .../memory.failcnt +5.5 usage_in_bytes + +As described in 2.1, memory cgroup uses res_counter for tracking and limiting +the memory usage. memory.usage_in_bytes shows the current res_counter usage for +memory, and DOESN'T show a actual usage of RSS and Cache. It is usually bigger +than the actual usage for a performance improvement reason. If you want to know +the actual usage, you can use memory.stat(see 5.2). +It's the same for memory.memsw.usage_in_bytes, which shows the current +res_counter usage for memory+swap. + 6. Hierarchy support The memory controller supports a deep hierarchy and hierarchical accounting. -- 1.7.1 -- 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/