From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752456Ab0IMVqp (ORCPT ); Mon, 13 Sep 2010 17:46:45 -0400 Received: from cpoproxy2-pub.bluehost.com ([67.222.39.38]:60246 "HELO cpoproxy2-pub.bluehost.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with SMTP id S1751683Ab0IMVqo convert rfc822-to-8bit (ORCPT ); Mon, 13 Sep 2010 17:46:44 -0400 DomainKey-Signature: a=rsa-sha1; q=dns; c=nofws; s=default; d=virtuousgeek.org; h=Received:Date:From:To:Cc:Subject:Message-ID:In-Reply-To:References:X-Mailer:Mime-Version:Content-Type:Content-Transfer-Encoding:X-Identified-User; b=GtuPDxU2pztfmgvwzjmYyJ+wYL4z5a8D6WyS+Fdmri9xn46Hij4O8AzZDFv4oMysJ5j0lZPpepv0e3cJwdgjJ6mMTokRv6WymcEUVcxcUX8SMLrLmHUQNJO5nXnftTHr; Date: Mon, 13 Sep 2010 14:46:32 -0700 From: Jesse Barnes To: Vasily Khoruzhick Cc: intel-gfx@lists.freedesktop.org, Thomas Gleixner , linux-kernel@vger.kernel.org Subject: Re: Interrupt latency on some 945GM platforms Message-ID: <20100913144632.35420d68@jbarnes-desktop> In-Reply-To: <201009140041.23645.anarsoul@gmail.com> References: <201009132336.17310.anarsoul@gmail.com> <201009140010.14783.anarsoul@gmail.com> <20100913141955.752cbdea@jbarnes-desktop> <201009140041.23645.anarsoul@gmail.com> X-Mailer: Claws Mail 3.7.6 (GTK+ 2.18.9; x86_64-redhat-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8BIT X-Identified-User: {10642:box514.bluehost.com:virtuous:virtuousgeek.org} {sentby:smtp auth 67.174.193.198 authed with jbarnes@virtuousgeek.org} Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, 14 Sep 2010 00:41:18 +0300 Vasily Khoruzhick wrote: > В сообщении от 14 of September 2010 00:19:55 автор Jesse Barnes написал: > > On Tue, 14 Sep 2010 00:10:08 +0300 > > > > Vasily Khoruzhick wrote: > > > В сообщении от 13 of September 2010 23:44:41 автор Jesse Barnes написал: > > > > I remember seeing a similar problem on an Eee PC I had; it seemed to be > > > > timer/interrupt related somehow. If I booted with clocksource=tsc > > > > (or maybe it was pit) I got nice smooth animations, but if I used the > > > > HPET things were really slow. > > > > > > > > Does the same work for you? > > > > > > Yeah, it works for me (will use it as temporary workaround). But it > > > definitely is not clean solution, as I can't use nohz mode with tsc > > > clocksource :) > > > > Thomas, does this ring any bells for you? > > > > I think the root symptom of the issue is that we get a much reduced i915 > > interrupt frequency (or no interrupts) on some 945GM platforms when > > using HPET as our clock source. > > > > In fact, on the platform I tested, it seemed that the i915 IRQs wouldn't > > generate interrupts at all when HPET was used. But shaking the mouse or > > generating network traffic was enough to get i915 interrupts coming in, > > even though neither of those interrupts were shared with the i915 > > device. > > > > Here's hoping you have some ideas to try... > > > > Thanks, > > Jesse, is it possible to disable wait for vsync somehow? cpufreq is not > working for me with nohz=no for some reason, as result cpu temperature and > power usage are higher. I prefer to see tearing but with low power usage and > without jerky keyboard :) Yes, you can set vblank_mode=0 in your environment or drirc. At least I think 0 is no vsync. :) -- Jesse Barnes, Intel Open Source Technology Center