From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757455Ab0IZKxw (ORCPT ); Sun, 26 Sep 2010 06:53:52 -0400 Received: from moutng.kundenserver.de ([212.227.126.187]:61648 "EHLO moutng.kundenserver.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757272Ab0IZKxv (ORCPT ); Sun, 26 Sep 2010 06:53:51 -0400 Message-ID: <4C9F262F.7030709@biereigel-wb.de> Date: Sun, 26 Sep 2010 12:53:35 +0200 From: Stefan Biereigel User-Agent: Mozilla/5.0 (Windows; U; Windows NT 6.1; de; rv:1.9.2.9) Gecko/20100915 Lightning/1.0b2 Thunderbird/3.1.4 MIME-Version: 1.0 To: linux-kernel@vger.kernel.org CC: Vasily Khoruzhick , Thomas Gleixner , Sitsofe Wheeler , Venkatesh Pallipadi , intel-gfx@lists.freedesktop.org, Len Brown , Jesse Barnes Subject: Re: Interrupt latency on some 945GM platforms References: <201009132336.17310.anarsoul@gmail.com> <201009162306.59508.anarsoul@gmail.com> <20100924123901.243c85e1@jbarnes-desktop> <201009242248.36554.anarsoul@gmail.com> <20100924125153.4fdf0c1b@jbarnes-desktop> In-Reply-To: <20100924125153.4fdf0c1b@jbarnes-desktop> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit X-Provags-ID: V02:K0:4Rbqs1DlbEL8NLbKBYw4EiX1+OR8XlmIoIDHWWgw8IC n4PfoAtaSKHLmIvVQQFHkZEsxeQcBukk8/4PPL6pkHr9r+IAbi K1pyLyBdhR16Kxi6srMmPAChfp9ZvAmXxDdtVQ5IVz/W4RJ9K7 M26mOGG2V8YuGy72VlFDA01Lrr5/QOERY6Gc1Ono+zLAZCrUEz fTBA725BSJWNgBoyDN4q1tQaPF41WHOuENakoSsK30= Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Am 24.09.2010 21:51, schrieb Jesse Barnes: > On Fri, 24 Sep 2010 22:48:36 +0300 > Vasily Khoruzhick wrote: > >> On 24 of September 2010 22:39:01 Jesse Barnes wrote: >>> On Thu, 16 Sep 2010 23:06:46 +0300 >>> >>> Vasily Khoruzhick wrote: >>>> В сообщении от 16 of September 2010 21:50:50 автор Thomas Gleixner >> написал: >>>>> Ok. The problematic part of HPET was not the clocksource, it was the >>>>> clock event device which failed to deliver interrupts occasionally. It >>>>> was worth a try at least. >>>> Hm, it seems that jerky glxgears is not related to jerky keyboard events. >>>> Keyboard is jerky only in konsole (kde terminal emulator), it seems >>>> something happened it seems that font rendering performance is much >>>> worse in latest xf86-video-intel than in xf86-video-intel-2.12.0. >>> Len just had me try a few things too: >>> - maxcpus=1 lets things work >>> - offlining cpu1 at runtime (echo 0 >>> >>> > /sys/devices/system/cpu/cpu1/online) lets things work >>> >>> - binding the i915 interrupt to cpu 0 does *not* help >>> >>> Vasily and Paolo, do you both have Atom CPUs with hyperthreading >>> enabled? >> Nope, I have Core2Duo T5500, dual-core, no hyperthreading :) > Hm, well there goes the theory about Atom HT... > Hello Everyone, just to add on to reports of this problem, there was a Thread here in LKML some months ago targeting the same problem (but not really attacking it at the Chipset driver). As I have one of those Laptops with a 945GM-Chipset and am stuck with the same Problem (disabled tickless now as a workaround and set ticks to 1000) I could maybe do some testing of patches. So what I can summarize is what the others did before: Disabling CPU1 helps, adding nohz=off helps, changing the Clocksource afterwards helps, binding the Interrupt does NOT help. So here's the Link to the old Discussion with follow-ups, maybe you can get some furter information from there. http://linux.derkeiler.com/Mailing-Lists/Kernel/2010-05/msg03696.html We targeted the BIOS itself as everyone in this thread happened to own an Phoenix BIOS with some special version string. best, Stefan