From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758426Ab2JSUCl (ORCPT ); Fri, 19 Oct 2012 16:02:41 -0400 Received: from mail-pa0-f46.google.com ([209.85.220.46]:56009 "EHLO mail-pa0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754768Ab2JSUCj (ORCPT ); Fri, 19 Oct 2012 16:02:39 -0400 Date: Fri, 19 Oct 2012 13:02:35 -0700 From: Tejun Heo To: Matt Helsley Cc: rjw@sisk.pl, oleg@redhat.com, cgroups@vger.kernel.org, containers@lists.linux-foundation.org, linux-kernel@vger.kernel.org Subject: Re: [PATCHSET cgroup/for-3.8] cgroup_freezer: allow migration regardless of freezer state and update locking Message-ID: <20121019200235.GN13370@google.com> References: <1350426526-14254-1-git-send-email-tj@kernel.org> <20121017191606.GA6223@us.ibm.com> <20121018211434.GI13370@google.com> <20121018222155.GB6223@us.ibm.com> <20121018223517.GQ13370@google.com> <20121018234726.GC6223@us.ibm.com> <20121019000153.GZ13370@google.com> <20121019012945.GD6223@us.ibm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20121019012945.GD6223@us.ibm.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 Hey, Matt. On Thu, Oct 18, 2012 at 06:29:45PM -0700, Matt Helsley wrote: > Yeah, that would be a nice cleanup too. I guess the ultra-careful way to > remove this feature would be something like: > > Add an internal migration restriction (which may or may not be > exported as a userspace interface in a subsequent > patch). > > Make the cgroup freezer use it. > > Make the cgroup freezer WARN_ONCE() when the subsystem is first > mounted. Indicates that the behavior is going to > change. > > ... time passes ... > > Remove the use of the migration "lock" from the cgroup freezer > and the WARN_ONCE(). > > Which would also make the feature more obvious. I don't think I'm gonna go that far for this. I don't think we need cgroup migration locking after all. Thanks. -- tejun From mboxrd@z Thu Jan 1 00:00:00 1970 From: Tejun Heo Subject: Re: [PATCHSET cgroup/for-3.8] cgroup_freezer: allow migration regardless of freezer state and update locking Date: Fri, 19 Oct 2012 13:02:35 -0700 Message-ID: <20121019200235.GN13370@google.com> References: <1350426526-14254-1-git-send-email-tj@kernel.org> <20121017191606.GA6223@us.ibm.com> <20121018211434.GI13370@google.com> <20121018222155.GB6223@us.ibm.com> <20121018223517.GQ13370@google.com> <20121018234726.GC6223@us.ibm.com> <20121019000153.GZ13370@google.com> <20121019012945.GD6223@us.ibm.com> Mime-Version: 1.0 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=2/sQtcBkElsTzo1aEUSiAvpdLhZRWPn9f1Sq0d/jsFQ=; b=f319Y1bvT3OlQgDg2uX020zBpGMG/8d6vU/HltXQmhBQa8sixlUtLvrwbCJeLQWPmG gtczSQks64aPoseO8FIr0b0Cl4rUy6GQXNEskt2PhQ/6OQJ51glUE4jFXewaK/MTQ/ru 5LPlIaUmlj0Cdqsa9IE+JvSzSDiDp4dq8eYM7VS18fzXayGU74XxvporXK5Jc48YvHfn 0u8gQ9wY9NrsU7fb5CTp0CxjxlGaGsDFNyy51+xCmk3M9nEDsUXFfRz7bQ23sgpOzKqg N4pVEy5drNGSVyxr9dmaxVNqVUVcSfmDlJBSvp7vnW6sdhMh1bfc+cZwFe1RLy4ziaIR rLYg== Content-Disposition: inline In-Reply-To: <20121019012945.GD6223-r/Jw6+rmf7HQT0dZR+AlfA@public.gmane.org> Sender: cgroups-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org List-ID: Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: Matt Helsley Cc: rjw-KKrjLPT3xs0@public.gmane.org, oleg-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org, cgroups-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, containers-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org, linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org Hey, Matt. On Thu, Oct 18, 2012 at 06:29:45PM -0700, Matt Helsley wrote: > Yeah, that would be a nice cleanup too. I guess the ultra-careful way to > remove this feature would be something like: > > Add an internal migration restriction (which may or may not be > exported as a userspace interface in a subsequent > patch). > > Make the cgroup freezer use it. > > Make the cgroup freezer WARN_ONCE() when the subsystem is first > mounted. Indicates that the behavior is going to > change. > > ... time passes ... > > Remove the use of the migration "lock" from the cgroup freezer > and the WARN_ONCE(). > > Which would also make the feature more obvious. I don't think I'm gonna go that far for this. I don't think we need cgroup migration locking after all. Thanks. -- tejun