Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753985AbXJWIIt (ORCPT ); Tue, 23 Oct 2007 04:08:49 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752324AbXJWIIU (ORCPT ); Tue, 23 Oct 2007 04:08:20 -0400 Received: from smtp-out.google.com ([216.239.33.17]:20400 "EHLO smtp-out.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752065AbXJWIIR (ORCPT ); Tue, 23 Oct 2007 04:08:17 -0400 DomainKey-Signature: a=rsa-sha1; s=beta; d=google.com; c=nofws; q=dns; h=received:message-id:date:from:to:subject:cc:in-reply-to: mime-version:content-type:content-transfer-encoding: content-disposition:references; b=acVQBWdv1b8K/aBEvmDkPLexwWMS4XRFoYrmjUXuFq2fuTVqP9xIfrq/a3LHIi8u1 Z1xkfVbHue+BJyKKPKd4Q== Message-ID: <6599ad830710230108r158ac4f4tf43d5a7ce2b374d2@mail.gmail.com> Date: Tue, 23 Oct 2007 01:08:07 -0700 From: "Paul Menage" To: balbir@linux.vnet.ibm.com Subject: Re: [PATCH 2/2] CFS CGroup: Report usage Cc: vatsa@linux.vnet.ibm.com, containers@lists.linux-foundation.org, "Andrew Morton" , "Ingo Molnar" , linux-kernel@vger.kernel.org In-Reply-To: <471DA974.8060509@linux.vnet.ibm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Content-Disposition: inline References: <471D4523.4040509@google.com> <20071023024036.GC3324@linux.vnet.ibm.com> <6599ad830710222306m6a3e3f52k4daf501836c05274@mail.gmail.com> <6599ad830710230021n536908c0xd95250f36aa8a27d@mail.gmail.com> <471DA78F.4090600@linux.vnet.ibm.com> <6599ad830710230053l35fffaf5ld8882eaae8b9df7c@mail.gmail.com> <471DA974.8060509@linux.vnet.ibm.com> Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 883 Lines: 22 On 10/23/07, Balbir Singh wrote: > > Well, without notify_on_release you can never be sure if a new task > got added to the control group or if someone acquired a reference > to it. I can't think of a safe way of removing control groups/cpusets > without using notify_on_release. > Using notify_on_release doesn't make any guarantees that the notification, or the action based on that notification, will occur before the cgroup becomes busy again. An rmdir() on a busy cgroup is perfectly safe, it just fails with -EBUSY. I'd just like to avoid making active control file fds trigger than failure mode. Paul - 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/