From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758950Ab3K1QTl (ORCPT ); Thu, 28 Nov 2013 11:19:41 -0500 Received: from mx1.redhat.com ([209.132.183.28]:12448 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754705Ab3K1QTi (ORCPT ); Thu, 28 Nov 2013 11:19:38 -0500 Date: Thu, 28 Nov 2013 17:20:25 +0100 From: Oleg Nesterov To: Peter Zijlstra Cc: Tejun Heo , zhang.yi20@zte.com.cn, lkml , Tetsuo Handa , Ingo Molnar Subject: Re: [PATCH]: exec: avoid propagating PF_NO_SETAFFINITY into userspace child Message-ID: <20131128162025.GA14937@redhat.com> References: <20131127183117.GB13098@mtj.dyndns.org> <20131128091358.GH10022@twins.programming.kicks-ass.net> <20131128114542.GA3826@redhat.com> <20131128121748.GN10022@twins.programming.kicks-ass.net> <20131128133152.GA821@redhat.com> <20131128133947.GR10022@twins.programming.kicks-ass.net> <20131128141329.GB3925@htj.dyndns.org> <20131128143857.GU10022@twins.programming.kicks-ass.net> <20131128153443.GB11956@redhat.com> <20131128154035.GE10022@twins.programming.kicks-ass.net> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20131128154035.GE10022@twins.programming.kicks-ass.net> User-Agent: Mutt/1.5.18 (2008-05-17) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 11/28, Peter Zijlstra wrote: > > On Thu, Nov 28, 2013 at 04:34:43PM +0100, Oleg Nesterov wrote: > > But note that in the longer term we might want even more. We probably > > want a non-daemonized thread controlled by the user-space. And even > > more, this thread should be per-namespace (this needs a lot more > > discussion). > > Which namespace? PID namespace I presume where we can have a 'new' init > task and everything. > > I'm not sure, are any of these things (workqueues, userspace helpers) > pid namespace aware? If not it doesn't seem to make sense to expose this > to nested PID namespaces and would be something special for the root > namespace. Not sure I understand correctly. But yes, of course, it is not that call_usermodehelper() should be namespace-friendly "unconditionally". We need another API (although perhaps we can simply add UMH_NAMESPACE flag, this doesn't matter). Just for example, the piped core handler. Currently it is hardly useful in containers. > > But whataver we do later, I believe that the patch from Zhang should > > be applied now. > > Probably, although with a much adjusted changelog. Zhang, please make v3 ;) Oleg.