From mboxrd@z Thu Jan 1 00:00:00 1970 From: Thomas Gleixner Subject: Re: [PATCH, v7] cgroups: introduce timer slack controller Date: Thu, 3 Mar 2011 08:34:25 +0100 (CET) Message-ID: References: <1299084001-3916-1-git-send-email-kirill@shutemov.name> <1299084001-3916-2-git-send-email-kirill@shutemov.name> <4D6F3C5B.8020307@cn.fujitsu.com> Mime-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Return-path: In-Reply-To: <4D6F3C5B.8020307-BthXqXjhjHXQFUHtdCDX3A@public.gmane.org> Sender: linux-api-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Li Zefan Cc: "Kirill A. Shutsemov" , Paul Menage , containers-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org, jacob.jun.pan-VuQAYsv1563Yd54FQh9/CA@public.gmane.org, Arjan van de Ven , linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, Matt Helsley , Andrew Morton , linux-api-u79uwXL29TY76Z2rM5mHXA@public.gmane.org List-Id: linux-api@vger.kernel.org On Thu, 3 Mar 2011, Li Zefan wrote: > >> +unsigned long get_task_timer_slack(struct task_struct *tsk) > >> +{ > >> + struct cgroup_subsys_state *css; > >> + struct tslack_cgroup *tslack_cgroup; > >> + unsigned long ret; > >> + > >> + rcu_read_lock(); > > > > Did you just remove the odd comment or actually figure out why you > > need rcu_read_lock() here ? > > > > It's necessary to protect against task exiting or task moving between cgroups. I know, though after the last review I wanted to make sure, that the author understands it as well and not just removed the odd comment just because I ranted about it :) Thanks, tglx