From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932526AbVHZGmk (ORCPT ); Fri, 26 Aug 2005 02:42:40 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S932527AbVHZGmk (ORCPT ); Fri, 26 Aug 2005 02:42:40 -0400 Received: from 213-239-205-147.clients.your-server.de ([213.239.205.147]:46732 "EHLO mail.tglx.de") by vger.kernel.org with ESMTP id S932526AbVHZGmj (ORCPT ); Fri, 26 Aug 2005 02:42:39 -0400 Subject: Re: 2.6.13-rc7-rt1 From: Thomas Gleixner Reply-To: tglx@linutronix.de To: dwalker@mvista.com Cc: Ingo Molnar , linux-kernel@vger.kernel.org In-Reply-To: <1125018945.14592.15.camel@dhcp153.mvista.com> 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> Content-Type: text/plain Organization: linutronix Date: Fri, 26 Aug 2005 08:43:17 +0200 Message-Id: <1125038597.20120.147.camel@tglx.tec.linutronix.de> Mime-Version: 1.0 X-Mailer: Evolution 2.2.3 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org 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. tglx