From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id ; Sun, 22 Dec 2002 15:44:19 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id ; Sun, 22 Dec 2002 15:44:19 -0500 Received: from franka.aracnet.com ([216.99.193.44]:2973 "EHLO franka.aracnet.com") by vger.kernel.org with ESMTP id ; Sun, 22 Dec 2002 15:44:18 -0500 Date: Sun, 22 Dec 2002 12:52:12 -0800 From: "Martin J. Bligh" To: "Protasevich, Natalie" , "Pallipadi, Venkatesh" , William Lee Irwin III cc: Christoph Hellwig , James Cleverdon , Linux Kernel , John Stultz , "Nakajima, Jun" , "Mallick, Asit K" , "Saxena, Sunil" , "Van Maren, Kevin" , Andi Kleen , Hubert Mantel , "Kamble, Nitin A" Subject: RE: [PATCH][2.4] generic cluster APIC support for systems with m ore than 8 CPUs Message-ID: <5540000.1040590331@titus> In-Reply-To: <3FAD1088D4556046AEC48D80B47B478C1AEC75@usslc-exch-4.slc.unisys.com> References: <3FAD1088D4556046AEC48D80B47B478C1AEC75@usslc-exch-4.slc.unisys. com> X-Mailer: Mulberry/2.2.1 (Linux/x86) MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit Content-Disposition: inline Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org > Some platforms (like certain ES7000s) won't tolerate any bit masks > programmed into the RTE because their balancing is done entirely in > hardware, similar to XTPR mechanism for Fosters. For those I suggest to > have an escape door, in the form of boot parameter such as > "irq_balance=no". It was suggested to us by SuSE and worked great - I > could turn it off in our platform code unconditionally. It could also > help those who can use irq balancing as is but might want to implement > their own balancing schema. Having a boot-time parameter is useful, but I'd like it to default to off without a paramater for the platforms where it's just broken. At the moment there's an "if (clustered_apic_mode) return;" stuck at the top of balance_irq, the latest series of patches changes that to "if (no_balance_irq) return;", which is set by NUMA-Q. If we can set up no_balance_irq to default correctly, but be possibly overridden by the boot-time parameter, I think we'd have the best of both worlds. M.