Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757304Ab3IKWCe (ORCPT ); Wed, 11 Sep 2013 18:02:34 -0400 Received: from mail-ea0-f175.google.com ([209.85.215.175]:42830 "EHLO mail-ea0-f175.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754566Ab3IKWCd (ORCPT ); Wed, 11 Sep 2013 18:02:33 -0400 Date: Thu, 12 Sep 2013 00:02:30 +0200 From: Frederic Weisbecker To: Christoph Lameter Cc: Andrew Morton , Gilad Ben-Yossef , Thomas Gleixner , Mike Frysinger , linux-kernel@vger.kernel.org, "Paul E. McKenney" Subject: Re: [RFC] Restrict kernel spawning of threads to a specified set of cpus. Message-ID: <20130911220228.GB15367@somewhere> References: <00000140efbcb701-c26320b3-f434-4538-bc80-8e92fed6f303-000000@email.amazonses.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <00000140efbcb701-c26320b3-f434-4538-bc80-8e92fed6f303-000000@email.amazonses.com> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1179 Lines: 29 On Thu, Sep 05, 2013 at 08:07:37PM +0000, Christoph Lameter wrote: > I am not sure how to call this kernel option but we need something like > that. I see drivers and the kernel spawning processes on the nohz cores. > The name kthread is not really catching the purpose. > > os_cpus=? highlatency_cpus=? > > > Subject: Restrict kernel spawning of threads to a specified set of cpus. > > Currently the kernel by default allows kernel threads to be spawned on > any cpu. This is a problem for low latency applications that want to > avoid Os actions on specific processors. > > Add a kernel option that restrict kthread and usermode spawning > to a specific set of processors. Also sets the affinities of > init by default to the restricted set since we certainly do not > want userspace daemons etc to be started there either. > > Signed-off-by: Christoph Lameter Why not do this from userspace instead? Thanks. -- 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/