Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754727AbbHXOBY (ORCPT ); Mon, 24 Aug 2015 10:01:24 -0400 Received: from mail-wi0-f176.google.com ([209.85.212.176]:34319 "EHLO mail-wi0-f176.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754357AbbHXOBW (ORCPT ); Mon, 24 Aug 2015 10:01:22 -0400 Message-ID: <1440424879.3670.42.camel@gmail.com> Subject: Re: [PATCH RESEND] sched/nohz: Affine unpinned timers to housekeepers From: Mike Galbraith To: Frederic Weisbecker Cc: Ingo Molnar , "Paul E. McKenney" , Peter Zijlstra , LKML , Vatika Harlalka , Chris Metcalf , Thomas Gleixner , Preeti U Murthy , Christoph Lameter Date: Mon, 24 Aug 2015 16:01:19 +0200 In-Reply-To: <20150824133559.GA27147@lerouge> References: <1439516774-4614-1-git-send-email-fweisbec@gmail.com> <20150823054032.GA28133@gmail.com> <20150823160101.GA11078@linux.vnet.ibm.com> <20150824064412.GA11581@gmail.com> <20150824133559.GA27147@lerouge> Content-Type: text/plain; charset="UTF-8" X-Mailer: Evolution 3.12.11 Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 792 Lines: 21 On Mon, 2015-08-24 at 15:36 +0200, Frederic Weisbecker wrote: > On Mon, Aug 24, 2015 at 08:44:12AM +0200, Ingo Molnar wrote: > > 2) > > > > What happens if the boot CPU is offlined? (under CONFIG_BOOTPARAM_HOTPLUG_CPU0=y) > > > > I don't see CPU hotplug callbacks fixing up the housekeeping_mask if the boot CPU > > is offlined. > > We have tick_nohz_cpu_down_callback() which makes sure that the timekeeper, which > is the boot CPU in nohz full, never gets offlined. Aha.. and it works fine too. (CPU0 told me to go away earlier;) -Mike -- 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/