From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751263AbWFLJVS (ORCPT ); Mon, 12 Jun 2006 05:21:18 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751250AbWFLJVS (ORCPT ); Mon, 12 Jun 2006 05:21:18 -0400 Received: from mx3.mail.elte.hu ([157.181.1.138]:45268 "EHLO mx3.mail.elte.hu") by vger.kernel.org with ESMTP id S1751263AbWFLJVR (ORCPT ); Mon, 12 Jun 2006 05:21:17 -0400 Date: Mon, 12 Jun 2006 11:20:23 +0200 From: Ingo Molnar To: =?iso-8859-1?Q?S=E9bastien_Dugu=E9?= Cc: linux-kernel@vger.kernel.org, Thomas Gleixner Subject: Re: 2.6.17-rc6-rt3 Message-ID: <20060612092023.GA30872@elte.hu> References: <20060610082406.GA31985@elte.hu> <1150104040.3835.3.camel@frecb000686> Mime-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <1150104040.3835.3.camel@frecb000686> User-Agent: Mutt/1.4.2.1i X-ELTE-SpamScore: 0.0 X-ELTE-SpamLevel: X-ELTE-SpamCheck: no X-ELTE-SpamVersion: ELTE 2.0 X-ELTE-SpamCheck-Details: score=0.0 required=5.9 tests=AWL,BAYES_50 autolearn=no SpamAssassin version=3.0.3 0.0 BAYES_50 BODY: Bayesian spam probability is 40 to 60% [score: 0.5137] 0.0 AWL AWL: From: address is in the auto white-list X-ELTE-VirusStatus: clean Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org * Sébastien Dugué wrote: > > I think all of the regressions reported against rt1 are fixed, please > > re-report if any of them is still unfixed. > > Great, boots fine on my dual Xeon and solves the ping problem I was > having. > > Thomas, any hint at what was going on? the problem was caused by a mismerge of the __raise_softirq_irqoff() changes of preempt-softirqs. In PREEMPT_SOFTIRQS, softirq activation means a wakeup of the softirq thread - hence __raise_softirq_irqoff() must wake up the softirq thead too. This didnt happen in -rt1 so the network softirq (which processes things like ping reply packets) got delayed to the natural softirq event - the next timer interrupt in the usual case. Hence depending on HZ you got a delay of 1-4-10 msecs (divided into two parts). Ingo