From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S265654AbUHAQSM (ORCPT ); Sun, 1 Aug 2004 12:18:12 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S265663AbUHAQSM (ORCPT ); Sun, 1 Aug 2004 12:18:12 -0400 Received: from pD9E0E790.dip.t-dialin.net ([217.224.231.144]:24197 "EHLO undata.org") by vger.kernel.org with ESMTP id S265654AbUHAQSJ (ORCPT ); Sun, 1 Aug 2004 12:18:09 -0400 Subject: Re: [patch] voluntary-preempt-2.6.8-rc2-M5 From: Thomas Charbonnel To: Ingo Molnar Cc: linux-kernel@vger.kernel.org, Andrew Morton , Lee Revell , Scott Wood In-Reply-To: <20040729222657.GA10449@elte.hu> References: <40F3F0A0.9080100@vision.ee> <20040713143947.GG21066@holomorphy.com> <1090732537.738.2.camel@mindpipe> <1090795742.719.4.camel@mindpipe> <20040726082330.GA22764@elte.hu> <1090830574.6936.96.camel@mindpipe> <20040726083537.GA24948@elte.hu> <1090832436.6936.105.camel@mindpipe> <20040726124059.GA14005@elte.hu> <20040726204720.GA26561@elte.hu> <20040729222657.GA10449@elte.hu> Content-Type: text/plain Message-Id: <1091377000.5392.18.camel@localhost> Mime-Version: 1.0 X-Mailer: Ximian Evolution 1.4.6 Date: Sun, 01 Aug 2004 18:16:41 +0200 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Ingo Molnar wrote : > i've uploaded the latest version of the voluntary-preempt patch: > > http://redhat.com/~mingo/voluntary-preempt/voluntary-preempt-2.6.8-rc2-M5 > This patch doesn't solve the latency spikes I see every ~8 seconds on my system. They still appear in latencytest when the rtc interrupt is the only non threaded interrupt on the system, and they still produce xruns in jack in conjunction with the keyboard even if the the sound card's interrupt is the only non threaded irq and jack's SCHED_FIFO priority is higher than the irq threads. I suspected a clock issue and switched from tsc to pmtmr without success. I now suspect a hardware issue (the machine is a laptop with a PIII M 1GHz cpu) or a scheduler corner case. Running jack at 96000Hz with 2 periods of 64 samples, I can see regular bursts of cpu usage every 2 or 3 seconds. Oprofile reveals that schedule is then the second most CPU intensive function on the system. Thomas