From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S266144AbUGEPlm (ORCPT ); Mon, 5 Jul 2004 11:41:42 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S266129AbUGEPld (ORCPT ); Mon, 5 Jul 2004 11:41:33 -0400 Received: from mail.gmx.net ([213.165.64.20]:25486 "HELO mail.gmx.net") by vger.kernel.org with SMTP id S266130AbUGEPlW (ORCPT ); Mon, 5 Jul 2004 11:41:22 -0400 X-Authenticated: #14349625 Message-Id: <5.2.1.1.2.20040705162139.00b1caa8@pop.gmx.net> X-Mailer: QUALCOMM Windows Eudora Version 5.2.1 Date: Mon, 05 Jul 2004 17:33:09 +0200 To: "Povolotsky, Alexander" , "'linux-kernel@vger.kernel.org'" From: Mike Galbraith Subject: RE: Maximum frequency of re-scheduling (minimum time quantum) que stio n In-Reply-To: <313680C9A886D511A06000204840E1CF08F42FD4@whq-msgusr-02.pit .comms.marconi.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii"; format=flowed Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org At 10:18 AM 7/5/2004 -0400, Povolotsky, Alexander wrote: >Mike - the part of my original question was - what is the minimum "measure" >(in time ticks or is fraction of the time tick ?) of that "(almost) any time >? In another words, assuming what is the latency between the moment, when >the higher priority process (or thread ) is becoming available to run (and >assuming that "schedule()" system call is not explicitly called at that time >...)and the moment when the scheduler STARTS (I am not including context >switch time into the question here) the process of preemtion (start of the >context switch). Is this time settable (at compile time ) ? Ah, you want wakeup latency numbers. Sorry, I don't have any. I believe Andrew and Davide both wrote tools for measuring in the wild, a search of the archives should turn up something that will give you the numbers you're looking for. If I'm understanding your question, no, there is no latency guarantee. > >If you're looking for an interface into the scheduler that allows you to > >twiddle slice length > >you mean at the run time (vs compile time), I assume ? Yes. -Mike