Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752478AbZGNBFN (ORCPT ); Mon, 13 Jul 2009 21:05:13 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752190AbZGNBFM (ORCPT ); Mon, 13 Jul 2009 21:05:12 -0400 Received: from fgwmail5.fujitsu.co.jp ([192.51.44.35]:33773 "EHLO fgwmail5.fujitsu.co.jp" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752096AbZGNBFL (ORCPT ); Mon, 13 Jul 2009 21:05:11 -0400 X-SecurityPolicyCheck-FJ: OK by FujitsuOutboundMailChecker v1.3.1 Date: Tue, 14 Jul 2009 10:03:20 +0900 From: KAMEZAWA Hiroyuki To: "Vladislav D. Buzov" Cc: Paul Menage , Linux Kernel Mailing List , Linux Containers Mailing List , Dan Malek , Andrew Morton , Balbir Singh Subject: Re: [PATCH 1/1] Memory usage limit notification addition to memcg Message-Id: <20090714100320.454ca54b.kamezawa.hiroyu@jp.fujitsu.com> In-Reply-To: <4A5BD8C5.1060902@embeddedalley.com> References: <1239660512-25468-1-git-send-email-dan@embeddedalley.com> <1246998310-16764-1-git-send-email-vbuzov@embeddedalley.com> <1246998310-16764-2-git-send-email-vbuzov@embeddedalley.com> <20090708095616.cdfe8c7c.kamezawa.hiroyu@jp.fujitsu.com> <6599ad830907131515h3c9622b5v309cf8f13d272bab@mail.gmail.com> <4A5BD8C5.1060902@embeddedalley.com> Organization: FUJITSU Co. LTD. X-Mailer: Sylpheed 2.5.0 (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: 1987 Lines: 52 On Mon, 13 Jul 2009 18:00:53 -0700 "Vladislav D. Buzov" wrote: > Paul Menage wrote: > > On Tue, Jul 7, 2009 at 5:56 PM, KAMEZAWA > > Hiroyuki wrote: > > > >> I know people likes to wait for file descriptor to get notification in these days. > >> Can't we have "event" file descriptor in cgroup layer and make it reusable for > >> other purposes ? > >> > > > > I agree - rather than having to add a separate "wait for value to > > cross X threshold" file for each numeric usage value that people might > > be concerned about, it would be better to have a generic way to do it > > for any file. Given that this is a userspace API, it would be better > > to work out at least the generic API first, even if the initial > > implementation isn't generic. > > "OOM" > > > We all agree on that. Our original intention was to create the memory > limit notification capability, not a generic mechanism for the cgroup > events. So, we started out with something that fits the current model. > > > - independent thresholds for different waiters > > > The threshold is one of the Memory Controller cgroup attributes, as well > as memory usage limit. It is not a user task attribute and should not be > controlled by user tasks. It's administrator or some control task job to > set memory usage parameters within the cgroup. Once the threshold is > reached, all tasks within the cgroup should be notified and do their > best to free the memory. > About this, I'll add following file. memory.reduce_usage --- try to reduce memory usage to be smaller than...? if your notifier goes in. Maybe good for dropping file caches etc.. for your notifer use case. Thanks, -Kame -- 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/