From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752989AbbDFXUP (ORCPT ); Mon, 6 Apr 2015 19:20:15 -0400 Received: from mx1.redhat.com ([209.132.183.28]:48324 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752673AbbDFXUM (ORCPT ); Mon, 6 Apr 2015 19:20:12 -0400 Message-ID: <552314A1.9090800@redhat.com> Date: Mon, 06 Apr 2015 19:20:01 -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: Marcelo Tosatti , Frederic Weisbecker CC: linux-kernel@vger.kernel.org, Thomas Gleixner Subject: Re: kernel/timer: avoid spurious ksoftirqd wakeups (v2) References: <20150406231557.GA5094@amt.cnet> In-Reply-To: <20150406231557.GA5094@amt.cnet> 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 On 04/06/2015 07:15 PM, Marcelo Tosatti wrote: > > > It is only necessary to raise timer softirq > in case there are active timers. > > Limit the ksoftirqd wakeup to that case. > > Fixes a latency spike with isolated CPUs and > nohz full mode. > > v2: fix variable initialization > do not raise timer softirq due to pending irqwork > > Reported-and-tested-by: Luiz Capitulino > Signed-off-by: Marcelo Tosatti Reviewed-by: Rik van Riel -- All rights reversed