From mboxrd@z Thu Jan 1 00:00:00 1970 From: Tejun Heo Subject: Re: [RFC] cgroup TODOs Date: Fri, 14 Sep 2012 10:59:44 -0700 Message-ID: <20120914175944.GF17747@google.com> References: <20120913205827.GO7677@google.com> <5052E7DF.7040000@parallels.com> <5052F4FF.6070508@huawei.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=sender:date:from:to:cc:subject:message-id:references:mime-version :content-type:content-disposition:in-reply-to:user-agent; bh=Z1Rs3omdtrRBtsn1jsVzEFjZO6UOuU+twVdUM9QUw2o=; b=oubeBEiNertHy6lAlLt5+bHbV/umcrLnhncTBQ8rHwDN2beU9rhH6KfMBTqHKlkIst 9i3NehnqUcAj2+buyOZvesPqof4dk2+G6JrRxYAMSOoVR+BA3yo0o31lwrzEB+wH1Qde xTVaYZdLGxEOGeEVtPzRqIqzXbHPFQa3kccnS8Hs8Y6eVCUqT6+DysOnNh11X9xbCMyq 0fK/l/4vE3qu/Hh+TbZc7P2x+1RpIrYhrsqt0XPcGw59MvDSJnXrG6Adf2JuZ4zdbPR9 Pfms+hXel3m9LG1eoaOzwkDDdSrqrdHtJcqb7iowOEg4oGtg0Y/AR6bYWz5cgn8VgVKD /cYQ== Content-Disposition: inline In-Reply-To: <5052F4FF.6070508-hv44wF8Li93QT0dZR+AlfA@public.gmane.org> List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: containers-bounces-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org Errors-To: containers-bounces-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org To: Li Zefan Cc: Lennart Poettering , Neil Horman , "Serge E. Hallyn" , containers-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org, Kay Sievers , linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, Michal Hocko , Ingo Molnar , Paul Mackerras , "Aneesh Kumar K.V" , Arnaldo Carvalho de Melo , Johannes Weiner , Thomas Graf , cgroups-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, Paul Turner Hello, On Fri, Sep 14, 2012 at 05:12:31PM +0800, Li Zefan wrote: > Agreed. The biggest issue in cpuset is if hotplug makes a cpuset's cpulist > empty the tasks in it will be moved to an ancestor cgroup, which requires > holding cgroup lock. We have to either change cpuset's behavior or eliminate > the global lock. Does that have to happen synchronously? Can't we have a cgroup operation which asynchronously pushes all tasks in a cgroup to its parent from a work item? Thanks. -- tejun From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754555Ab2INR7w (ORCPT ); Fri, 14 Sep 2012 13:59:52 -0400 Received: from mail-pz0-f46.google.com ([209.85.210.46]:36303 "EHLO mail-pz0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751026Ab2INR7u (ORCPT ); Fri, 14 Sep 2012 13:59:50 -0400 Date: Fri, 14 Sep 2012 10:59:44 -0700 From: Tejun Heo To: Li Zefan Cc: Glauber Costa , containers@lists.linux-foundation.org, cgroups@vger.kernel.org, linux-kernel@vger.kernel.org, Michal Hocko , Peter Zijlstra , Paul Turner , Johannes Weiner , Thomas Graf , "Serge E. Hallyn" , Paul Mackerras , Ingo Molnar , Arnaldo Carvalho de Melo , Neil Horman , "Aneesh Kumar K.V" , "Daniel P. Berrange" , Lennart Poettering , Kay Sievers Subject: Re: [RFC] cgroup TODOs Message-ID: <20120914175944.GF17747@google.com> References: <20120913205827.GO7677@google.com> <5052E7DF.7040000@parallels.com> <5052F4FF.6070508@huawei.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <5052F4FF.6070508@huawei.com> User-Agent: Mutt/1.5.20 (2009-06-14) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hello, On Fri, Sep 14, 2012 at 05:12:31PM +0800, Li Zefan wrote: > Agreed. The biggest issue in cpuset is if hotplug makes a cpuset's cpulist > empty the tasks in it will be moved to an ancestor cgroup, which requires > holding cgroup lock. We have to either change cpuset's behavior or eliminate > the global lock. Does that have to happen synchronously? Can't we have a cgroup operation which asynchronously pushes all tasks in a cgroup to its parent from a work item? Thanks. -- tejun