From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1750987AbWJEU6A (ORCPT ); Thu, 5 Oct 2006 16:58:00 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751303AbWJEU6A (ORCPT ); Thu, 5 Oct 2006 16:58:00 -0400 Received: from cantor2.suse.de ([195.135.220.15]:31116 "EHLO mx2.suse.de") by vger.kernel.org with ESMTP id S1750996AbWJEU57 (ORCPT ); Thu, 5 Oct 2006 16:57:59 -0400 To: Ingo Molnar Cc: Thomas Gleixner , LKML , John Stultz , Valdis Kletnieks , Arjan van de Ven , Dave Jones , David Woodhouse , Jim Gettys , Roman Zippel , akpm@osdl.org Subject: Re: [patch 00/22] high resolution timers / dynamic ticks - V3 References: <20061004172217.092570000@cruncher.tec.linutronix.de> <20061005011608.b69e3461.akpm@osdl.org> <20061005081725.GA28877@elte.hu> From: Andi Kleen Date: 05 Oct 2006 22:57:24 +0200 In-Reply-To: <20061005081725.GA28877@elte.hu> Message-ID: User-Agent: Gnus/5.09 (Gnus v5.9.0) Emacs/21.3 MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Ingo Molnar writes: > * Andrew Morton wrote: > > > With CONFIG_HIGH_RES_TIMERS=y, CONFIG_NO_HZ=n it's pretty sick. It > > pauses for several seconds after "input: AlpsPS/2 ALPS GlidePoint as > > /class/input/input2" (printk-time claims 2 seconds, but it was longer > > than that). > > > > It's been stuck for a minute or more at the 12.980000 time, seems to > > have hung. The cursor is flashing extremely slowly. > > ah, that's still the VAIO, right? Do you get a 'slow' LOC count on > /proc/interrupts even on a stock kernel? If yes then that's a > fundamentally sick local APIC timer interrupt. Stock kernel should show > sickness too, if for example you boot an SMP kernel on it - can you > confirm that? (the UP-IOAPIC only relies for profiling on the lapic > timer, so there the only sickness you should see on the stock kernel is > a non-working readprofile) When I was hacking on my old noidletick patch I ran into this problem on several machines too. But usually the problem wasn't that it was too slow, but that it completely stopped in C2 or deeper. I don't think there is a way to work around that except for not using C2 or deeper (not an option) or using a different timer source. If that is true then hitting space lots of time will make it go faster. -andi