From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id ; Wed, 24 Jan 2001 07:32:15 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id ; Wed, 24 Jan 2001 07:32:06 -0500 Received: from hermes.mixx.net ([212.84.196.2]:29195 "HELO hermes.mixx.net") by vger.kernel.org with SMTP id ; Wed, 24 Jan 2001 07:31:50 -0500 Message-ID: <3A6ECA9A.AD9200E7@innominate.de> Date: Wed, 24 Jan 2001 13:29:14 +0100 From: Daniel Phillips Organization: innominate X-Mailer: Mozilla 4.72 [de] (X11; U; Linux 2.4.0-test10 i586) X-Accept-Language: en MIME-Version: 1.0 To: Joe deBlaquiere , linux-kernel@vger.kernel.org Subject: Re: more on scheduler benchmarks In-Reply-To: <20010122101738.B7427@w-mikek.des.sequent.com> <3A6CEB02.3050906@redhat.com> Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Joe deBlaquiere wrote: > > Maybe I've been off in the hardware lab for too long, but how about > > 1. using ioperm to give access to the parallel port. > 2. have your program write a byte (thread id % 256 ?) constantly to the > port during it's other activity > 3. capture the results from another computer with an ecp port > > This way you don't run the risk of altering the scheduler behavior with > your logging procedure. It's a technique I've used in debugging realtime systems. It works great, but bear in mind that the out to the parallel port costs an awful lot of cycles. You *will* alter the behaviour of the scheduler. -- Daniel - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org Please read the FAQ at http://www.tux.org/lkml/