Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753371Ab0ADKPJ (ORCPT ); Mon, 4 Jan 2010 05:15:09 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753353Ab0ADKPG (ORCPT ); Mon, 4 Jan 2010 05:15:06 -0500 Received: from ey-out-2122.google.com ([74.125.78.25]:18447 "EHLO ey-out-2122.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751694Ab0ADKPF convert rfc822-to-8bit (ORCPT ); Mon, 4 Jan 2010 05:15:05 -0500 MIME-Version: 1.0 In-Reply-To: <20100104003612.GF16187@balbir.in.ibm.com> References: <20100104003612.GF16187@balbir.in.ibm.com> Date: Mon, 4 Jan 2010 12:15:02 +0200 Message-ID: Subject: Re: [PATCH v5 0/4] cgroup notifications API and memory thresholds From: "Kirill A. Shutemov" To: balbir@linux.vnet.ibm.com Cc: containers@lists.linux-foundation.org, linux-mm@kvack.org, Paul Menage , Li Zefan , Andrew Morton , KAMEZAWA Hiroyuki , Pavel Emelyanov , Dan Malek , Vladislav Buzov , Daisuke Nishimura , Alexander Shishkin , linux-kernel@vger.kernel.org Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8BIT Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2244 Lines: 52 On Mon, Jan 4, 2010 at 2:36 AM, Balbir Singh wrote: > * Kirill A. Shutemov [2009-12-30 17:57:55]: > >> This patchset introduces eventfd-based API for notifications in cgroups and >> implements memory notifications on top of it. >> >> It uses statistics in memory controler to track memory usage. >> >> Output of time(1) on building kernel on tmpfs: >> >> Root cgroup before changes: >>       make -j2  506.37 user 60.93s system 193% cpu 4:52.77 total >> Non-root cgroup before changes: >>       make -j2  507.14 user 62.66s system 193% cpu 4:54.74 total >> Root cgroup after changes (0 thresholds): >>       make -j2  507.13 user 62.20s system 193% cpu 4:53.55 total >> Non-root cgroup after changes (0 thresholds): >>       make -j2  507.70 user 64.20s system 193% cpu 4:55.70 total >> Root cgroup after changes (1 thresholds, never crossed): >>       make -j2  506.97 user 62.20s system 193% cpu 4:53.90 total >> Non-root cgroup after changes (1 thresholds, never crossed): >>       make -j2  507.55 user 64.08s system 193% cpu 4:55.63 total >> >> Any comments? > > Hi, > > I just saw that the notification work for me using the tool you > supplied. One strange thing was that I got notified even though > the amount of data I was using was reducing, so I hit the notification > two ways > >        +------------+----------- >                    1G >                ----> (got notified on increase) >                <---- (got notified on decrease) > > I am not against the behaviour, but it can be confusing unless > clarified with the event. IIUC, you've got two events. One on crossing the threshold up and one on crossing it down. It's Ok. By design, notification means that the threshold probably crossed (it can be crossed twice -- up and down) or the cgroup was removed. To understand what really happen you need to check if the cgroup exists and read current usage of the resource. -- 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/