Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755094AbYFBWgR (ORCPT ); Mon, 2 Jun 2008 18:36:17 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752138AbYFBWgG (ORCPT ); Mon, 2 Jun 2008 18:36:06 -0400 Received: from smtprelay11.ispgateway.de ([80.67.29.28]:43929 "EHLO smtprelay11.ispgateway.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751165AbYFBWgE (ORCPT ); Mon, 2 Jun 2008 18:36:04 -0400 From: Ingo Oeser To: Paul Jackson Subject: Re: Inquiry: Should we remove "isolcpus= kernel boot option? (may have realtime uses) Date: Tue, 3 Jun 2008 00:35:55 +0200 User-Agent: KMail/1.9.9 Cc: linux-kernel@vger.kernel.org, Con Kolivas , "Derek L. Fults" , devik , Dimitri Sivanich , Dinakar Guniguntala , Emmanuel Pacaud , Frederik Deweerdt , Ingo Molnar , Matthew Dobson , Max Krasnyansky , Nick Piggin , rostedt@goodmis.org, Oleg Nesterov , "Paul E. McKenney" , Paul Menage , Peter Zijlstra , "Randy.Dunlap" , suresh.b.siddha@intel.com, Thomas Gleixner References: <20080601213019.14ea8ef8.pj@sgi.com> In-Reply-To: <20080601213019.14ea8ef8.pj@sgi.com> MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit Content-Disposition: inline Message-Id: <200806030035.58387.ioe-lkml@rameria.de> X-Df-Sender: 849595 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1085 Lines: 32 Hi Paul, in short: NAK! On Monday 02 June 2008, Paul Jackson wrote: > (Aside to the RealTime folks -- is there a 'realtime' > email list which I should include in this discussion?) > > The kernel has a "isolcpus=" kernel boot time parameter. This > parameter isolates CPUs from scheduler load balancing, minimizing the > impact of scheduler latencies on realtime tasks running on those CPUs. I used it to mask out a defect CPU on a 8-CPU node of a HPC-cluster at a customer site, until the $BIG_VENDOR sent a replacement. And to prove $BIG_VENDOR, that we actually have a problem on THAT CPU. So I would really like to keep this fault isolation capability. I made my customer happy with that. I wish Linux had more such "mask out bad hardware" features to faciliate fault isolation and boot and runtime. Best Regards Ingo Oeser -- 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/