From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S265022AbUHHCrH (ORCPT ); Sat, 7 Aug 2004 22:47:07 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S265029AbUHHCrH (ORCPT ); Sat, 7 Aug 2004 22:47:07 -0400 Received: from viper.oldcity.dca.net ([216.158.38.4]:6026 "HELO viper.oldcity.dca.net") by vger.kernel.org with SMTP id S265022AbUHHCrE (ORCPT ); Sat, 7 Aug 2004 22:47:04 -0400 Subject: Re: [patch] preempt-timing-on-2.6.8-rc2-O2 From: Lee Revell To: William Lee Irwin III Cc: Ingo Molnar , linux-kernel In-Reply-To: <20040808023941.GQ17188@holomorphy.com> References: <20040802073938.GA8332@elte.hu> <1091435237.3024.9.camel@mindpipe> <20040802092855.GA15894@elte.hu> <20040802100815.GA18349@elte.hu> <20040802101840.GB2334@holomorphy.com> <20040802103516.GA20584@elte.hu> <20040802105100.GA22855@elte.hu> <1091932214.1150.3.camel@mindpipe> <20040808023306.GP17188@holomorphy.com> <1091932615.1150.6.camel@mindpipe> <20040808023941.GQ17188@holomorphy.com> Content-Type: text/plain Message-Id: <1091933229.1150.15.camel@mindpipe> Mime-Version: 1.0 X-Mailer: Ximian Evolution 1.4.6 Date: Sat, 07 Aug 2004 22:47:09 -0400 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Sat, 2004-08-07 at 22:39, William Lee Irwin III wrote: > On Sat, 2004-08-07 at 22:33, William Lee Irwin III wrote: > >> This seems to be 996us spent in do_IRQ() when it interrupts idle tasks. > > On Sat, Aug 07, 2004 at 10:36:55PM -0400, Lee Revell wrote: > > I am not sure I understand how preemption can be disabled for 996us and > > not cause an xrun. > > You were idling at the time, so the latency affected nothing, except > perhaps task migration on SMP. > Would it be possible to detect this situation and treat it like a preemptible section, just so the sheer volume of printks does not cause a problem? Lee