Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752880AbbDDOKt (ORCPT ); Sat, 4 Apr 2015 10:10:49 -0400 Received: from mx1.redhat.com ([209.132.183.28]:44107 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752595AbbDDOKs (ORCPT ); Sat, 4 Apr 2015 10:10:48 -0400 Message-ID: <551FF0B9.4010907@redhat.com> Date: Sat, 04 Apr 2015 10:10:01 -0400 From: Rik van Riel User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:31.0) Gecko/20100101 Thunderbird/31.4.0 MIME-Version: 1.0 To: Chris Metcalf , Frederic Weisbecker CC: "Peter Zijlstra (Intel)" , "Paul E. McKenney" , "Rafael J. Wysocki" , Martin Schwidefsky , Ingo Molnar , linux-kernel@vger.kernel.org Subject: Re: [PATCH 2/2] nohz: make nohz_full imply isolcpus References: <1428078248-5425-1-git-send-email-cmetcalf@ezchip.com> <1428078248-5425-2-git-send-email-cmetcalf@ezchip.com> <20150403174258.GC13598@lerouge> <551EE7F4.6070406@ezchip.com> In-Reply-To: <551EE7F4.6070406@ezchip.com> Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1338 Lines: 37 On 04/03/2015 03:20 PM, Chris Metcalf wrote: > On 04/03/2015 01:42 PM, Frederic Weisbecker wrote: >> On Fri, Apr 03, 2015 at 12:24:08PM -0400, cmetcalf@ezchip.com wrote: >>> From: Chris Metcalf >>> >>> It's not clear that nohz_full is useful without isolcpus also >>> set, since otherwise the scheduler has to run periodically to >>> try to determine whether to steal work from other cores. >>> >>> Signed-off-by: Chris Metcalf >> I think Rick has a similar patch. > > I didn't see anything relevant in linux-next, though I did see > cpu_isolated_map > made into a public symbol in a recent commit by Rik. I have a few patches in cgroups/for-4.1 as well that export information about isolated and nohz_full cpus in /sys/devices/system/cpu/ > Rik, what's the change you're proposing that's similar to this one? Thanks! I don't have this particular one, and I like it. I know there are use cases where isolcpus= without nohz_full= makes sense, but I cannot think of the reverse. Acked-by: Rik van Riel -- All rights reversed -- 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/