Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756284Ab1FUMWu (ORCPT ); Tue, 21 Jun 2011 08:22:50 -0400 Received: from relay2.sgi.com ([192.48.179.30]:33403 "EHLO relay.sgi.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1754888Ab1FUMWn (ORCPT ); Tue, 21 Jun 2011 08:22:43 -0400 Message-Id: <20110621122242.086384966@sgi.com> User-Agent: quilt/0.47-1 Date: Tue, 21 Jun 2011 07:21:26 -0500 From: cpw@sgi.com To: linux-kernel@vger.kernel.org Cc: mingo@elte.hu, x86@kernel.org Subject: [patch 1/8 v5] x86, UV: smp_processor_id in a preemptable region References: <20110621122125.688884227@sgi.com> Content-Disposition: inline; filename=tlb_uv_smpcpu Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1195 Lines: 37 Fix a call by tunables_write() to smp_processor_id() within a preemptable region. Call get_cpu()/put_cpu() around the region where the returned cpu number is actually used, which makes it non-preemptable. Signed-off-by: Cliff Wickman --- A DEBUG_PREEMPT warning is prevented. UV does not support cpu hotplug yet, but this is a step toward that ability. arch/x86/platform/uv/tlb_uv.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) Index: linux/arch/x86/platform/uv/tlb_uv.c =================================================================== --- linux.orig/arch/x86/platform/uv/tlb_uv.c +++ linux/arch/x86/platform/uv/tlb_uv.c @@ -1334,9 +1334,10 @@ static ssize_t tunables_write(struct fil instr[count] = '\0'; - bcp = &per_cpu(bau_control, smp_processor_id()); - + cpu = get_cpu(); + bcp = &per_cpu(bau_control, cpu); ret = parse_tunables_write(bcp, instr, count); + put_cpu(); if (ret) return ret; -- 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/