From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755069AbXKZMQd (ORCPT ); Mon, 26 Nov 2007 07:16:33 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1754391AbXKZMQY (ORCPT ); Mon, 26 Nov 2007 07:16:24 -0500 Received: from gprs189-60.eurotel.cz ([160.218.189.60]:1048 "EHLO spitz.ucw.cz" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1754287AbXKZMQX (ORCPT ); Mon, 26 Nov 2007 07:16:23 -0500 Date: Mon, 26 Nov 2007 11:54:18 +0000 From: Pavel Machek To: Thomas Gleixner Cc: Ingo Molnar , kernel list Subject: Re: nohz and strange sleep latencies Message-ID: <20071126115417.GB4701@ucw.cz> References: <20071119203152.GA1772@elf.ucw.cz> <20071119205555.GA28696@elte.hu> <20071119211142.GA1857@elf.ucw.cz> <20071120085704.GA19950@elte.hu> <20071120105458.GA1597@elf.ucw.cz> <20071120205454.GD10008@elte.hu> <20071120225246.GA24380@elte.hu> <20071122185238.GA1821@elf.ucw.cz> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.9i Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Hi! > > > but perhaps somehow we miss this fact and fail to turn off the lapic > > > clockevents drivers? > > > > Ok, I guess I'm lost. If I offline second CPU, I immediately get > > 1000Hz timer tick... is that expected? > > Hmm. No. I have no idea why this is happening. > > 34196 total events, 55.083 events/sec > echo 0 >/sys/devices/system/cpu/cpu1/online > 36073 total events, 54.679 events/sec It happened again, this time on 2.6.24-pre-rc1 (mostly untainted). Reboot and problem goes away... so this one is random :-(. I'll try plug/unplug loops, perhaps that can trigger it reliably. (cpu replug does not fix it once triggered). Pavel -- (english) http://www.livejournal.com/~pavelmachek (cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html