Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754408Ab3ITKlV (ORCPT ); Fri, 20 Sep 2013 06:41:21 -0400 Received: from www.linutronix.de ([62.245.132.108]:39773 "EHLO Galois.linutronix.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754246Ab3ITKlU (ORCPT ); Fri, 20 Sep 2013 06:41:20 -0400 Date: Fri, 20 Sep 2013 12:41:02 +0200 (CEST) From: Thomas Gleixner To: Christoph Lameter cc: Andrew Morton , Gilad Ben-Yossef , Tejun Heo , John Stultz , Mike Frysinger , Minchan Kim , Hakan Akkan , Max Krasnyansky , Frederic Weisbecker , "linux-kernel@vger.kernel.org" , "Paul E. McKenney" , Linux-MM Subject: Re: RFC vmstat: On demand vmstat threads In-Reply-To: <000001413796641f-017482d3-1194-499b-8f2a-d7686c1ae61f-000000@email.amazonses.com> Message-ID: References: <00000140e9dfd6bd-40db3d4f-c1be-434f-8132-7820f81bb586-000000@email.amazonses.com> <0000014109b8e5db-4b0f577e-c3b4-47fe-b7f2-0e5febbcc948-000000@email.amazonses.com> <20130918150659.5091a2c3ca94b99304427ec5@linux-foundation.org> <000001413796641f-017482d3-1194-499b-8f2a-d7686c1ae61f-000000@email.amazonses.com> User-Agent: Alpine 2.02 (DEB 1266 2009-07-14) MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII X-Linutronix-Spam-Score: -1.0 X-Linutronix-Spam-Level: - X-Linutronix-Spam-Status: No , -1.0 points, 5.0 required, ALL_TRUSTED=-1,SHORTCIRCUIT=-0.0001 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1139 Lines: 32 On Thu, 19 Sep 2013, Christoph Lameter wrote: > On Thu, 19 Sep 2013, Thomas Gleixner wrote: > > > The vmstat accounting is not the only thing which we want to delegate > > to dedicated core(s) for the full NOHZ mode. > > > > So instead of playing broken games with explicitly not exposed core > > code variables, we should implement a core code facility which is > > aware of the NOHZ details and provides a sane way to delegate stuff to > > a certain subset of CPUs. > > I would be happy to use such a facility. Otherwise I would just be adding > yet another kernel option or boot parameter I guess. Uuurgh, no. The whole delegation stuff is necessary not just for vmstat. We have the same issue for scheduler stats and other parts of the kernel, so we are better off in having a core facility to schedule such functions in consistency with the current full NOHZ state. Thanks, tglx -- 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/