From mboxrd@z Thu Jan 1 00:00:00 1970 From: Peter Zijlstra Subject: Re: [PATCHSET] cgroup, sched: restructure threadgroup locking and replace it with a percpu_rwsem Date: Mon, 18 May 2015 22:06:55 +0200 Message-ID: <20150518200655.GB19282@twins.programming.kicks-ass.net> References: <1431549318-16756-1-git-send-email-tj@kernel.org> <20150518163440.GA24861@htj.duckdns.org> Mime-Version: 1.0 Return-path: Content-Disposition: inline In-Reply-To: <20150518163440.GA24861-piEFEHQLUPpN0TnZuCh8vA@public.gmane.org> Sender: cgroups-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org List-ID: Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: Tejun Heo Cc: lizefan-hv44wF8Li93QT0dZR+AlfA@public.gmane.org, cgroups-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, mingo-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org, linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org On Mon, May 18, 2015 at 12:34:40PM -0400, Tejun Heo wrote: > On Wed, May 13, 2015 at 04:35:15PM -0400, Tejun Heo wrote: > > threadgroup locking was added because cgroup needs threadgroups to > > stay stable across attach operations. It was implemented as a > > per-signal_struct generic locking mechanism so that other users which > > require threadgroups stable across blocking operations can use it too; > > however, it hasn't grown any other use cases and still conditionalized > > on CONFIG_CGROUPS. > > Ingo, Peter, what do you guys think? I had a brief look and didn't spot anhything really weird. I'll try and give is a little more time tomorrow. On routing I think you can take it through the cgroup tree if Ingo is ok with that.