From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1760816AbXGPTq5 (ORCPT ); Mon, 16 Jul 2007 15:46:57 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753731AbXGPTqt (ORCPT ); Mon, 16 Jul 2007 15:46:49 -0400 Received: from py-out-1112.google.com ([64.233.166.182]:38845 "EHLO py-out-1112.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753192AbXGPTqs convert rfc822-to-8bit (ORCPT ); Mon, 16 Jul 2007 15:46:48 -0400 DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=beta; h=received:message-id:date:from:reply-to:to:subject:cc:mime-version:content-type:content-transfer-encoding:content-disposition; b=ncxbTaPPKiyxj4Ktb0Sk0A7XRVGDinuf/wnEaa99bX3TXugP9g9DmpjN2UCTrFJvicuMuZ7IIoPH2Bo9F5eQVp+Pb6ncSyp43r06OP6mgTOMSXP7ROOwF8ydRoTimqL8WitGAUU4Ij8kfouDKHgafU9qh9UrviIMWCCeUFLIPaI= Message-ID: <3efb10970707161246se06ab22i32872cfe6fa4f2f6@mail.gmail.com> Date: Mon, 16 Jul 2007 21:46:46 +0200 From: "Remy Bohmer" Reply-To: linux@bohmer.net To: LKML , RT-Users Subject: [Question] Hooks for scheduler tracing (CFS) Cc: mathieu.desnoyers@polymtl.ca, "Ingo Molnar" MIME-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 8BIT Content-Disposition: inline Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Hello, I am looking for some tool/kernel machanism that enables me to track every schedule change on the CFS scheduler of the RT-kernel for some period of time. Thus a tool that gives me an overview after some time which task got "scheduled in/out" at "which timestamp" and at "which CPU". ( I need the raw data) In a far past (on Montavista kernels) I used LTT for this to log for some time with only the SCHED_CHANGE filter and text output. But, I cannot find any LTT(ng) support for any RT-kernel, and support for the new CFS (like in 2.6.22.1-rt4) is even harder. So I was wondering if anybody knows some tool/kernel mechanism which can do this? If not, I will build a kernel extension for it myself (new extension to 'latency_trace' ?) In that case can anybody with in depth CFS scheduler knowledge please point me which hooks are safe to use for this? I need it to get a detailed insight in my RT-system with its RT and non-RT applications. Thus to know when a certain task gets scheduled (and to calculate its per thread min/max/avg latencies), which task preempts another task, and to get a complete overview of what the RT system (and scheduler) is doing during time etc. Kind Regards, Remy Böhmer