From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S263782AbTEFPDn (ORCPT ); Tue, 6 May 2003 11:03:43 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S263783AbTEFPDm (ORCPT ); Tue, 6 May 2003 11:03:42 -0400 Received: from franka.aracnet.com ([216.99.193.44]:36038 "EHLO franka.aracnet.com") by vger.kernel.org with ESMTP id S263782AbTEFPDK (ORCPT ); Tue, 6 May 2003 11:03:10 -0400 Date: Tue, 06 May 2003 08:15:02 -0700 From: "Martin J. Bligh" To: Keith Mannthey , lkml cc: Andrew Morton , James Cleverdon Subject: Re: [RFC][PATCH] fix for clusterd io_apics Message-ID: <13960000.1052234101@[10.10.2.4]> In-Reply-To: <1052179450.16886.224.camel@dyn9-47-17-180.beaverton.ibm.com> References: <1051744032.16886.80.camel@dyn9-47-17-180.beaverton.ibm.com><20030430163637.04f06ba6.akpm@digeo.com><1051751157.16886.91.camel@dyn9-47-17-180.beaverton.ibm.com> <20030430192205.13491d61.akpm@digeo.com> <1052179450.16886.224.camel@dyn9-47-17-180.beaverton.ibm.com> X-Mailer: Mulberry/2.2.1 (Linux/x86) MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Content-Disposition: inline Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org > The following is a patch to fix inconsistent use of the function > set_ioapic_affinity. In the current kernel it is unclear as to weather > the value being passed to the function is a cpu mask or valid apic id. > In irq_affinity_write_proc the kernel passes on a cpu mask but the kirqd > thread passes on logical apic ids. In flat apic mode this is not an > issue because a cpu mask represents the apic value. However in > clustered apic mode the cpu mask is very different from the logical apic > id. > This is an attempt to do the right thing for clustered apics. I > clarify that the value being passed to set_ioapic_affinity is a cpu mask > not a apicid. Set_ioapic_affinity will do the conversion to logical > apic ids. Since many cpu masks don't map to valid apicids in clustered > apic mode TARGET_CPUS is used as a default value when such a situation > occurs. I think this is a good step in making irq_affinity clustered > apic safe. Thanks Keith, looks great. The existing code in the main kernel is just broken (and confusing as hell with it's mixed use of "mask"). M.