Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755866Ab1FOPps (ORCPT ); Wed, 15 Jun 2011 11:45:48 -0400 Received: from relay1.sgi.com ([192.48.179.29]:38170 "EHLO relay.sgi.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752379Ab1FOPpp (ORCPT ); Wed, 15 Jun 2011 11:45:45 -0400 To: linux-kernel@vger.kernel.org Subject: [PATCH 1/8 v2] x86, UV: smp_processor_id in a preemptable region Cc: mingo@elte.hu Message-Id: From: Cliff Wickman Date: Wed, 15 Jun 2011 10:46:56 -0500 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1254 Lines: 36 From: Cliff Wickman Calling smp_processor_id() from within a preemptable region will issue a warning if DEBUG_PREEMPT is set. Which cpu is returned by smp_processor_id() is actually arbitrary here, as every cpu has a per-cpu structure with the needed limit for the tunable. But the call should be non-preemptable to avoid a warning in a DEBUG_PREEMPT kernel. Diffed against 3.0.0-rc3 Signed-off-by: Cliff Wickman --- arch/x86/platform/uv/tlb_uv.c | 2 ++ 1 file changed, 2 insertions(+) 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 @@ -1334,7 +1334,9 @@ static ssize_t tunables_write(struct fil instr[count] = '\0'; + preempt_disable(); /* avoid DEBUG_PREEMPT warning */ bcp = &per_cpu(bau_control, smp_processor_id()); + preempt_enable_no_resched(); ret = parse_tunables_write(bcp, instr, count); if (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/