From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756714Ab0JKWCP (ORCPT ); Mon, 11 Oct 2010 18:02:15 -0400 Received: from mail-fx0-f46.google.com ([209.85.161.46]:48022 "EHLO mail-fx0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756513Ab0JKWCN (ORCPT ); Mon, 11 Oct 2010 18:02:13 -0400 DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=sender:message-id:date:from:user-agent:mime-version:to:cc:subject :references:in-reply-to:x-enigmail-version:content-type :content-transfer-encoding; b=vMd9jVIke4/dgmk+O/Z3a7IpWcinTLSqcyXsLUfG/VKKDMK5k4kiYOuukwZHdtlsRR HKTD3q50eb/+l0jUvJXSNsQ45EN1Gq3173+SgcfeukiqfIS66Db8RMbsy2jEn6myfSWG SmZwEFQS4hsK8ac1ROw2kTCt3wuPr/i8DZ2JM= Message-ID: <4CB38960.5070306@suse.cz> Date: Tue, 12 Oct 2010 00:02:08 +0200 From: Jiri Slaby User-Agent: Mozilla/5.0 (X11; U; Linux x86_64; cs-CZ; rv:1.9.2.9) Gecko/20100914 SUSE/3.1.4 Thunderbird/3.1.4 MIME-Version: 1.0 To: Thomas Gleixner CC: LKML , clemens@ladisch.de, venki@google.com, the arch/x86 maintainers Subject: Re: HPET causes tasks to freeze (still in 2.6.36-rc6) References: <4CA9F471.2080704@suse.cz> In-Reply-To: X-Enigmail-Version: 1.1.2 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 10/04/2010 06:31 PM, Thomas Gleixner wrote: > On Mon, 4 Oct 2010, Jiri Slaby wrote: >> HPET as a clocksource has still issues in the latest kernels (confirmed >> in 2.6.36-rc6) at least on x86_64. Unless clocksource=jiffies, >> clocksource=tsc or nolapic_timer is used, the system is unusable. Tasks >> are not woken unless mouse is moved, key is pressed (or other hard irq >> triggered). 2.6.32 seems to be the last working. > > The problem is not clocksource related, it's NOHZ related. > > clocksource=jiffies, clocksource=tsc are disabling NOHZ simply because > we can not do NOHZ neither with jiffies nor with a TSC which stops in > deeper C-states. > > nolapic_timer installs a dummy lapic timer so the lapic is not used, > but HPET is used instead and NOHZ is disabled as well. > > So the real problem is that the hpet broadcast interrupts which are > used to work around the lapic timer stops in C3 problem are not coming > through for whatever reason. > > So the question is what changed in the ACPI/idle NOHZ code which might > expose this problem. > > Can we get dmesg, output of proc/timer_list and output of > /proc/acpi/processor/CPU0/power for a .32 and a non working kernel > please ? Sure: http://labs.suse.cz/jslaby/bug-579932/ thanks, -- js suse labs