Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933531Ab3IMNvk (ORCPT ); Fri, 13 Sep 2013 09:51:40 -0400 Received: from a14-70.smtp-out.amazonses.com ([54.240.14.70]:56531 "EHLO a14-70.smtp-out.amazonses.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932122Ab3IMNvj (ORCPT ); Fri, 13 Sep 2013 09:51:39 -0400 X-Greylist: delayed 342 seconds by postgrey-1.27 at vger.kernel.org; Fri, 13 Sep 2013 09:51:38 EDT Date: Fri, 13 Sep 2013 13:45:55 +0000 From: Christoph Lameter X-X-Sender: cl@gentwo.org To: Frederic Weisbecker cc: Andrew Morton , Gilad Ben-Yossef , Thomas Gleixner , Mike Frysinger , linux-kernel@vger.kernel.org, "Paul E. McKenney" , Peter Zijlstra , Ingo Molnar Subject: Re: [RFC] Restrict kernel spawning of threads to a specified set of cpus. In-Reply-To: <20130912183023.GA25386@somewhere> Message-ID: <00000141179222e5-8a10141c-7b95-4204-853c-ab266fd08532-000000@email.amazonses.com> References: <00000140efbcb701-c26320b3-f434-4538-bc80-8e92fed6f303-000000@email.amazonses.com> <20130911220228.GB15367@somewhere> <000001411282afa6-fe9c0543-0447-492b-991e-dc8214884b88-000000@email.amazonses.com> <20130912141625.GA23357@somewhere> <00000141128d759a-44dcacb6-8f48-4f9b-8381-d14003bd6da1-000000@email.amazonses.com> <20130912143137.GA23839@somewhere> <0000014112a921ae-51d171bf-e8d4-4569-bd20-94dabda2d5ba-000000@email.amazonses.com> <20130912151102.GB23839@somewhere> <0000014112d66287-d0abaeb1-71ff-48a0-8740-f984d47400a7-000000@email.amazonses.com> <20130912183023.GA25386@somewhere> User-Agent: Alpine 2.02 (DEB 1266 2009-07-14) MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII X-SES-Outgoing: 2013.09.13-54.240.14.70 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 903 Lines: 20 On Thu, 12 Sep 2013, Frederic Weisbecker wrote: > So yeah it's a problem in theory. Now in practice, I have yet to be convinced because > this should be solved after a few iterations in /proc in most cases. I have seen some drivers regularly spawning threads all over the machnine. This is a practical issue that I am addresing. > > Now the issue doesn't only concern kthreads but all tasks in the system. > If we really want to solve that race, then may be we can think of a kernel_parameter > that sets the initial affinity of init and then lets get it naturally inherited > through the whole tree. This patch that we are discussing does exactly that. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/