From mboxrd@z Thu Jan 1 00:00:00 1970 From: Li Zefan Subject: Re: [PATCH 6/6] cgroup, memcg: implement css->id and convert css_from_id() to use it Date: Mon, 28 Apr 2014 11:33:16 +0800 Message-ID: <535DCBFC.4000404@huawei.com> References: <1398373333-1521-1-git-send-email-tj@kernel.org> <1398373333-1521-7-git-send-email-tj@kernel.org> Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <1398373333-1521-7-git-send-email-tj-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org> Sender: cgroups-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org List-ID: Content-Type: text/plain; charset="us-ascii" To: Tejun Heo Cc: cgroups-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, hannes-druUgvl0LCNAfugRpC6u6w@public.gmane.org, mhocko-AlSwsSmVLrQ@public.gmane.org, nasa4836-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org On 2014/4/25 5:02, Tejun Heo wrote: > Until now, cgroup->id has been used to identify all the associated > csses and css_from_id() takes cgroup ID and returns the matching css > by looking up the cgroup and then dereferencing the css associated > with it; however, now that the lifetimes of cgroup and css are > separate, this is incorrect and breaks on the unified hierarchy when a > controller is disabled and enabled back again before the previous > instance is released. > > This patch adds css->id which is a subsystem-unique ID and converts > css_from_id() to look up by the new css->id instead. memcg is the > only user of css_from_id() and also converted to use css->id instead. > netprio_cgroup also needs to be updated. > For traditional hierarchies, this shouldn't make any functional > difference. > > Signed-off-by: Tejun Heo > Cc: Johannes Weiner > Cc: Michal Hocko > Cc: Jianyu Zhan > --- > include/linux/cgroup.h | 9 ++++++++ > kernel/cgroup.c | 59 ++++++++++++++++++++++++++++++++------------------ > mm/memcontrol.c | 4 ++-- > 3 files changed, 49 insertions(+), 23 deletions(-) >