From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755140AbYIEVlA (ORCPT ); Fri, 5 Sep 2008 17:41:00 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752241AbYIEVkX (ORCPT ); Fri, 5 Sep 2008 17:40:23 -0400 Received: from relay1.sgi.com ([192.48.171.29]:54830 "EHLO relay.sgi.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1751862AbYIEVkV (ORCPT ); Fri, 5 Sep 2008 17:40:21 -0400 Message-Id: <20080905214019.821172000@polaris-admin.engr.sgi.com> User-Agent: quilt/0.47-1 Date: Fri, 05 Sep 2008 14:40:19 -0700 From: Mike Travis To: Ingo Molnar , Andrew Morton Cc: Jack Steiner , Jes Sorensen , David Miller , Thomas Gleixner , linux-kernel@vger.kernel.org Subject: [PATCH 0/3] smp: reduce stack requirements for smp_call_function_mask Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org * Cleanup cpumask_t usages in smp_call_function_mask function chain to prevent stack overflow problem when NR_CPUS=4096. * Reduce the number of passed cpumask_t variables in the following call chain for x86_64: smp_call_function_mask --> arch_send_call_function_ipi-> smp_ops.send_call_func_ipi --> genapic->send_IPI_mask Since the smp_call_function_mask() is an EXPORTED function, we cannot change it's calling interface for a patch to 2.6.27. The smp_ops.send_call_func_ipi interface is internal only and has two arch provided functions: arch/x86/kernel/smp.c: .send_call_func_ipi = native_send_call_func_ipi arch/x86/xen/smp.c: .send_call_func_ipi = xen_smp_send_call_function_ipi arch/x86/mach-voyager/voyager_smp.c: (uses native_send_call_func_ipi) Therefore modifying the internal interface to use a cpumask_t pointer is straight-forward. The changes to genapic are much more extensive and are affected by the recent additions of the x2apic modes, so they will be done for 2.6.28 only. Based on 2.6.27-rc5-git6. Applies to linux-2.6.tip/master (with FUZZ). Signed-off-by: Mike Travis ---