Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754484AbYJAWJv (ORCPT ); Wed, 1 Oct 2008 18:09:51 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753369AbYJAWJo (ORCPT ); Wed, 1 Oct 2008 18:09:44 -0400 Received: from fg-out-1718.google.com ([72.14.220.155]:21049 "EHLO fg-out-1718.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753330AbYJAWJn (ORCPT ); Wed, 1 Oct 2008 18:09:43 -0400 DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=message-id:date:from:sender:to:subject:cc:in-reply-to:mime-version :content-type:content-transfer-encoding:content-disposition :references:x-google-sender-auth; b=dLZOTa3RYjpY/QOH15JIGHBVMdXjQhXk2r1bu1eknHpkTKlHWzDL/rM0MbrHi3g8P3 kc2uZ+an9WPHyhYhwiug1ixVO5qEBuyOJE8zZockwg9u+fGAhcgAcxwusn/yOT60OvFd E6V3R5XJ27OIxtKBvfpLlaNQMef8H9xYJyfU0= Message-ID: <2c0942db0810011509j6c35911fh55c4e3178caf7f04@mail.gmail.com> Date: Wed, 1 Oct 2008 15:09:40 -0700 From: "Ray Lee" To: "Marek Szuba" Subject: Re: Regular system 'hiccups' with 2.6.25+ on amd64 machines Cc: linux-kernel@vger.kernel.org In-Reply-To: <20081001235106.57edede4@ifurita.akmm.lan> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Content-Disposition: inline References: <20081001235106.57edede4@ifurita.akmm.lan> X-Google-Sender-Auth: 4415b6e7d8dc18b4 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3642 Lines: 74 On Wed, Oct 1, 2008 at 2:51 PM, Marek Szuba wrote: > Hello everyone, > > While I am not sure whether this is a bug or not, the phenomenon is > rather peculiar so I have decided to ask here. The problem is, upgrading > the kernel on any of my two AMD64 boxes from 2.6.24 to 2.6.25 or newer > causes both systems to get "hiccups", that it every half a second or so > they briefly freeze. Below you will find two examples of the problem: > > 1. On both systems, refreshing icons in the system tray takes much more > time than before: whereas with 2.6.24 the flicker of icons as they get > updated is barely noticeable, with 2.6.25+ you can see it quite clearly > and sometimes you can even see blank background of the tray app. > > 2. On the weaker of the two systems (Athlon64 3500+, 2 GB RAM, > nForce-based motherboard, on-board sound device supported by the > intel8x0 ALSA driver), one can hear audio playback (tested primarily > on a Shoutcast stream) stutter on a regular basis even with > buffering enabled. With 2.6.24 this never happened, even under heavy > system load. > > 3. I run an instance of Internet DJ Console (idjc), which used JACK, on > the stronger of the two systems (Athlon64 4000+, 2 GB RAM, nForce-based > motherboard, Sound Blaster Audigy 2 PCI card with ALSA driver emu10k1). > Up to and including 2.6.24 I've never had any problems with streaming > to the Icecast server I use, even under relatively heavy system load - > those few xruns, of just a few ms each, that did happen were removed by > buffering. However, under 2.6.25 and up I start getting xruns as soon > as idjc starts, even before I connect to the Icecast server or start > broadcasting anything! These look as follows: > > **** alsa_pcm: xrun of at least 1222893019070.464 msecs > > (the value is always the same) and appear more-or-less twice per > second. When I do connect to the server and begin streaming, the sound > as received by clients is audibly choppy when the system is otherwise > idle and becomes extremely distorted under load. The problem persists > after switching to an Icecast server running on the same machine, or indeed > if instead of running an independent media client I enable (in idjc) > listening to the stream before it gets sent to the server. > > > As I mentioned earlier, the problem affects all kernel versions I have > tried from 2.6.25 up to and including 2.6.26.5 - both vanilla versions > and with the grsecurity patch applied. Attached you will find my config > files for 2.6.24.7 and 2.6.26.5. Unfortunately I do not know whether the > problem affects other architectures than amd64. > > I would greatly appreciate it if you could look into the problem and > let me know what is wrong - i.e. whether this is a bug, an > unnecessarily-enabled feature, something that just needs a bit of > tuning and so on. If you need any more information regarding the issue, > my set-ups and so on, please don't hesitate to contact me (by > writing to my e-mail address - I'm not subscribed to LKML at present)! > > Yours sincerely, > -- > MS > $ bzgrep -i group config.2.6.26.5.bz2 # CONFIG_CGROUPS is not set CONFIG_GROUP_SCHED=y CONFIG_FAIR_GROUP_SCHED=y # CONFIG_RT_GROUP_SCHED is not set # CONFIG_CGROUP_SCHED is not set The group scheduler has (or at least had, prior to now) known fairness and interactivity issues. Please disable it and try again. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/