Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754617Ab3IJH4p (ORCPT ); Tue, 10 Sep 2013 03:56:45 -0400 Received: from mail-la0-f41.google.com ([209.85.215.41]:55694 "EHLO mail-la0-f41.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753444Ab3IJH4o (ORCPT ); Tue, 10 Sep 2013 03:56:44 -0400 MIME-Version: 1.0 X-Originating-IP: [212.179.42.66] In-Reply-To: <1378797995.6046.54.camel@marge.simpson.net> References: <00000140efbcb701-c26320b3-f434-4538-bc80-8e92fed6f303-000000@email.amazonses.com> <1378795659.6046.41.camel@marge.simpson.net> <1378797995.6046.54.camel@marge.simpson.net> Date: Tue, 10 Sep 2013 10:56:43 +0300 Message-ID: Subject: Re: [RFC] Restrict kernel spawning of threads to a specified set of cpus. From: Gilad Ben-Yossef To: Mike Galbraith Cc: Christoph Lameter , Andrew Morton , Thomas Gleixner , Frederic Weisbecker , 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: 1368 Lines: 42 On Tue, Sep 10, 2013 at 10:26 AM, Mike Galbraith wrote: > > Hammering on the wrong spot makes removing isolcpus take longer, and > adds up to more hammering in the long run, no? Hearing you mention > isolcpus, I just thought I should mention that it wants to go away, so > might not be the optimal spot for isolation related tinkering. OK, so I'll bite - isolcpu currently has special magic to do its thing but AFAIK part of the reason isolcpu works "better" (for some definition of better, for some work loads) is simply because it blocks migration earlier than you get with cpusets. What if we re-did the implementation of isolcpu as creating an cpuset with migration off as early as possible in the boot process, prior to spawning init? So basically, isolcpus becomes just a way to configure a cpuset early? 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/