From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753546Ab2AaGb1 (ORCPT ); Tue, 31 Jan 2012 01:31:27 -0500 Received: from mail.wdtv.com ([66.118.69.84]:34938 "EHLO mail.wdtv.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752866Ab2AaGbZ (ORCPT ); Tue, 31 Jan 2012 01:31:25 -0500 From: Gene Heskett To: Mike Galbraith , LKML , emc-users@lists.sourceforge.net Subject: Re: isolcpus question Date: Tue, 31 Jan 2012 01:31:19 -0500 User-Agent: KMail/1.13.7 (Linux/2.6.38.8-pclos2.pae.bfs; KDE/4.6.5; i686; ; ) References: <201201302213.39672.gene.heskett@gmail.com> <1327985246.6667.8.camel@marge.simson.net> In-Reply-To: <1327985246.6667.8.camel@marge.simson.net> MIME-Version: 1.0 Content-Type: Text/Plain; charset="windows-1256" Content-Transfer-Encoding: 7bit Message-Id: <201201310131.20239.gene.heskett@gmail.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Monday, January 30, 2012, Mike Galbraith wrote: >On Mon, 2012-01-30 at 22:13 -0500, Gene Heskett wrote: >> Which is, is there a isolcpus troubleshooting tool? >> >> I have an app that is supposed to use the 2nd cpu on a 2 core atom >> system all by itself, and its insisting on using cpu0 when the boot >> command line has "isolcpus=1" appended to it, and apparently I am the >> only one with the problem, its working for about 200-500 others >> running the same software. > >isolcpus=1 isolates CPU1 so no task will automatically end up using it, >but it's up to your task (or you) to move to the isolated CPU. Pin your >task to CPU1 with taskset, and all should work fine. > > -Mike Cross-posted back to the emc-users list, others might find it useful also. Mike, you're a genius. The man page for taskset is a bit obtuse but the first stab at a '/usr/bin/lcnc' script: ------------- #!/bin/bash taskset 0x00000002 emc -l exit 0 ------------- Seems to launch this application and I believe its now working better than ever before. Now I need to do some experimenting to see just how fast I can make linuxcnc's base_thread run without the rest of the box getting laggy. The faster I can make that thread run, the faster and smoother my steppers driving my milling machine will run. I have already cut it down to 30 u-secs from 65 u-secs and it is still only using about 26% of the target cpu1. Amazing IMO. Thank you very much Mike. Cheers, Gene -- "There are four boxes to be used in defense of liberty: soap, ballot, jury, and ammo. Please use in that order." -Ed Howdershelt (Author) My web page: When a lion meets another with a louder roar, the first lion thinks the last a bore. -- G.B. Shaw