From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757350Ab1LNPIH (ORCPT ); Wed, 14 Dec 2011 10:08:07 -0500 Received: from mail-qy0-f174.google.com ([209.85.216.174]:54167 "EHLO mail-qy0-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757338Ab1LNPIB (ORCPT ); Wed, 14 Dec 2011 10:08:01 -0500 Date: Wed, 14 Dec 2011 16:07:56 +0100 From: Frederic Weisbecker To: Tejun Heo Cc: Andrew Morton , LKML , Paul Menage , Li Zefan , Johannes Weiner , Aditya Kali , Oleg Nesterov , Kay Sievers , Tim Hockin , "Kirill A. Shutemov" , Containers Subject: Re: [PATCH 00/10] cgroups: Task counter subsystem v6 Message-ID: <20111214150752.GB10791@somewhere.redhat.com> References: <1317668832-10784-1-git-send-email-fweisbec@gmail.com> <20111213155848.GI25802@google.com> <20111213190642.GB2421@somewhere.redhat.com> <20111213204918.GK25802@google.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20111213204918.GK25802@google.com> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Dec 13, 2011 at 12:49:18PM -0800, Tejun Heo wrote: > Hello, > > On Tue, Dec 13, 2011 at 08:06:46PM +0100, Frederic Weisbecker wrote: > > On Tue, Dec 13, 2011 at 07:58:48AM -0800, Tejun Heo wrote: > > > Can you please rebase the patchset on top of cgroup/for-3.3? > > > > Sure. But please note its fate is still under discussion. Whether > > we want it upstream is still a running debate. But I certainly > > need to rebase against your tree. > > I see. > > > > I primarily like the idea of being able to track process usage w/ cgroup > > > and enforce limits on it but hope that it could somehow integrate w/ > > > cgroup freezer. ie. trigger freezer if it goes over limit and let the > > > userland tool / administrator deal with the frozen cgroup. I'm > > > planning on extending cgroup freezer such that it supports recursive > > > freezing and killing of frozen tasks. If we can fit task counters > > > into that, we'll have general method of handling problematic cgroups - > > > freeze, notify userland and let it deal with it. > > > > Hmm, so you suggest a kernel trigger that freeze the cgroup when the > > task limit is reached? > > Yeah, something like that. I'm not really sure about how it would > actually work tho. > > > What about rather implementing register_event() for the tasks.usage such > > that the user can be notified using eventfd when the limit is reached. > > Then it would be up to the user to decide to freeze or any other thing. > > Sounds like a more generic solution. > > Maybe, the problem would be how to ensure that the userland manager > can respond fast enough (whatever that means...). Yeah that's part of the goal of the task counter: limit the spreading of the forkbomb soon enough such that the machine stays responsive and the admin can react accordingly.