From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751583AbVHZOSG (ORCPT ); Fri, 26 Aug 2005 10:18:06 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751585AbVHZOSG (ORCPT ); Fri, 26 Aug 2005 10:18:06 -0400 Received: from gateway-1237.mvista.com ([12.44.186.158]:37362 "EHLO av.mvista.com") by vger.kernel.org with ESMTP id S1751583AbVHZOSF (ORCPT ); Fri, 26 Aug 2005 10:18:05 -0400 Subject: Re: 2.6.13-rc7-rt1 From: Daniel Walker To: tglx@linutronix.de Cc: Ingo Molnar , linux-kernel@vger.kernel.org In-Reply-To: <1125038597.20120.147.camel@tglx.tec.linutronix.de> References: <20050825062651.GA26781@elte.hu> <1125012596.14592.12.camel@dhcp153.mvista.com> <1125015724.20120.143.camel@tglx.tec.linutronix.de> <1125018945.14592.15.camel@dhcp153.mvista.com> <1125038597.20120.147.camel@tglx.tec.linutronix.de> Content-Type: text/plain Date: Fri, 26 Aug 2005 07:17:41 -0700 Message-Id: <1125065862.7896.0.camel@c-67-188-6-232.hsd1.ca.comcast.net> Mime-Version: 1.0 X-Mailer: Evolution 2.0.4 (2.0.4-6) Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Fri, 2005-08-26 at 08:43 +0200, Thomas Gleixner wrote: > On Thu, 2005-08-25 at 18:15 -0700, Daniel Walker wrote: > > On Fri, 2005-08-26 at 02:22 +0200, Thomas Gleixner wrote: > > > On Thu, 2005-08-25 at 16:29 -0700, Daniel Walker wrote: > > > > Devastating latency on a 3Ghz xeon .. Maybe the raw_spinlock in the > > > > timer base is creating a unbounded latency? > > > > > > The lock is only held for really short periods. The only possible long > > > period would be migration of timers from a dead hotplug cpu to another. > > > I guess thats not the case. > > > > > > Do you have HIGH_RES_TIMERS enabled ? > > > > No. The cascade has a very long worst case. > > You mean the cascading from the outer to the inner wheels ? That should > only happen with tons of active timers. Right .. Daniel