From mboxrd@z Thu Jan 1 00:00:00 1970 From: Kamezawa Hiroyuki Subject: Re: [PATCH 7/9] cgroup_freezer: introduce CGROUP_FREEZING_[SELF|PARENT] Date: Thu, 08 Nov 2012 13:56:52 +0900 Message-ID: <509B3B94.1070407@jp.fujitsu.com> References: <1351931915-1701-1-git-send-email-tj@kernel.org> <1351931915-1701-8-git-send-email-tj@kernel.org> <509B382E.4030707@jp.fujitsu.com> <20121108044521.GH2660@mtj.dyndns.org> Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20121108044521.GH2660@mtj.dyndns.org> Sender: linux-pm-owner@vger.kernel.org List-ID: Content-Type: text/plain; charset="us-ascii"; format="flowed" To: Tejun Heo Cc: lizefan@huawei.com, mhocko@suse.cz, rjw@sisk.pl, linux-pm@vger.kernel.org, fweisbec@gmail.com, containers@lists.linux-foundation.org, linux-kernel@vger.kernel.org, cgroups@vger.kernel.org (2012/11/08 13:45), Tejun Heo wrote: > Hello, > > On Thu, Nov 08, 2012 at 01:42:22PM +0900, Kamezawa Hiroyuki wrote: >> (2012/11/03 17:38), Tejun Heo wrote: >>> Introduce FREEZING_SELF and FREEZING_PARENT and make FREEZING OR of >>> the two flags. This is to prepare for full hierarchy support. >>> >>> freezer_apply_date() is updated such that it can handle setting and >>> clearing of both flags. The two flags are also exposed to userland >>> via read-only files self_freezing and parent_freezing. >>> >>> Other than the added cgroupfs files, this patch doesn't introduce any >>> behavior change. >>> >>> Signed-off-by: Tejun Heo >> >> What is the purpose of FREEZING_SELG/PARENT, having 2 flags and >> make it visible to users ? > > SELF is the configuration of the current cgroup, PARENT is freezing > state inherited from an ancestor. If either is set, the cgroup is > freezing. Without the two conditions visible to userland, it can get > a bit confusing as echoing "THAWED" to state may not do anything to > the cgroup. > Got it, thank you. I'm glad if you add some more explanation in comments and considered use-case in changelog. Reviewed-by: KAMEZAWA Hiroyuki Thanks, -Kame