Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756918Ab3IONrc (ORCPT ); Sun, 15 Sep 2013 09:47:32 -0400 Received: from mail-la0-f43.google.com ([209.85.215.43]:43227 "EHLO mail-la0-f43.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751925Ab3IONrb (ORCPT ); Sun, 15 Sep 2013 09:47:31 -0400 MIME-Version: 1.0 X-Originating-IP: [212.179.42.66] In-Reply-To: <20130912141625.GA23357@somewhere> 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> Date: Sun, 15 Sep 2013 16:47:29 +0300 Message-ID: Subject: Re: [RFC] Restrict kernel spawning of threads to a specified set of cpus. From: Gilad Ben-Yossef To: Frederic Weisbecker Cc: Christoph Lameter , Andrew Morton , Thomas Gleixner , Mike Frysinger , "linux-kernel@vger.kernel.org" , "Paul E. McKenney" Content-Type: text/plain; charset=ISO-8859-1 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1107 Lines: 34 On Thu, Sep 12, 2013 at 5:16 PM, Frederic Weisbecker wrote: > On Thu, Sep 12, 2013 at 02:10:56PM +0000, Christoph Lameter wrote: >> On Thu, 12 Sep 2013, Frederic Weisbecker wrote: >> >> > Why not do this from userspace instead? >> >> Because the cpumasks are hardcoded in the kernel code. >> > > Ok but you can change the affinity of a kthread from userspace, as > long as you define a cpu set that is among that kthread's cpus allowed. There is also the problem of kernel threads registering timers. We don't have a good way to migrate those yet, I believe. Gilad -- Gilad Ben-Yossef Chief Coffee Drinker gilad@benyossef.com Israel Cell: +972-52-8260388 US Cell: +1-973-8260388 http://benyossef.com "If you take a class in large-scale robotics, can you end up in a situation where the homework eats your dog?" -- Jean-Baptiste Queru -- 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/