Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S263736AbUCXPLe (ORCPT ); Wed, 24 Mar 2004 10:11:34 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S263741AbUCXPLe (ORCPT ); Wed, 24 Mar 2004 10:11:34 -0500 Received: from holomorphy.com ([207.189.100.168]:33668 "EHLO holomorphy.com") by vger.kernel.org with ESMTP id S263736AbUCXPLd (ORCPT ); Wed, 24 Mar 2004 10:11:33 -0500 Date: Wed, 24 Mar 2004 07:11:11 -0800 From: William Lee Irwin III To: Takashi Iwai Cc: Andrea Arcangeli , Nick Piggin , Andrew Morton , mjy@geizhals.at, linux-kernel@vger.kernel.org Subject: Re: CONFIG_PREEMPT and server workloads Message-ID: <20040324151111.GG791@holomorphy.com> Mail-Followup-To: William Lee Irwin III , Takashi Iwai , Andrea Arcangeli , Nick Piggin , Andrew Morton , mjy@geizhals.at, linux-kernel@vger.kernel.org References: <40591EC1.1060204@geizhals.at> <20040318060358.GC29530@dualathlon.random> <20040318015004.227fddfb.akpm@osdl.org> <20040318145129.GA2246@dualathlon.random> <405A584B.40601@cyberone.com.au> <20040319050948.GN2045@holomorphy.com> <20040320121423.GA9009@dualathlon.random> <20040320145111.GD2045@holomorphy.com> <20040320150311.GN9009@dualathlon.random> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.5.1+cvs20040105i Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1320 Lines: 28 On Wed, Mar 24, 2004 at 02:57:20PM +0100, Takashi Iwai wrote: > http://www.alsa-project.org/~iwai/audio-latency.pdf > the data there are already old (based on 2.6.0-test9), and were > measured by the old version of latency-test program (modifed version > from Benno Senor's latencytest suite). > basically, the latency-test program measures the latency between the > time of (periodical) irq and the time when user RT-thread is woken > up under different workloads. the user thread can perform an > artificial CPU load (busy loop) to simulate the situation that any RT > process does a heavy job. > the resultant plot shows the critical deadline, the total latency and > the CPU latency (busy loop) responses, as you can see in the above > pdf. > the latest version of latency-test suite is found at > http://www.alsa-project.org/~iwai/latencytest-0.5.3.tar.gz > it uses its own kernel module to generate irqs from RTC and to trace > stacks. > i'll show the results of the recent kernels tomorrow... Very nice. This document is the kind of thing I wanted to see. -- wli - 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/