Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757874AbZJGSUh (ORCPT ); Wed, 7 Oct 2009 14:20:37 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1756519AbZJGSUg (ORCPT ); Wed, 7 Oct 2009 14:20:36 -0400 Received: from mx1.redhat.com ([209.132.183.28]:29379 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751051AbZJGSUf (ORCPT ); Wed, 7 Oct 2009 14:20:35 -0400 Date: Wed, 7 Oct 2009 20:19:32 +0200 (CEST) From: John Kacur X-X-Sender: jkacur@localhost.localdomain To: tglx@linutronix.de, Ingo Molnar , linux-kernel@vger.kernel.org cc: linux-rt-users@vger.kernel.org, Clark Williams Subject: [PATCH RFC] BKL not necessary in cpuid_open Message-ID: User-Agent: Alpine 2.00 (LFD 1167 2008-08-23) MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1558 Lines: 47 I've been staring at the BKL lock in cpuid_open, and I can't see what it is protecting. However, I may have missed something - even something obvious, so comments are welcome. >From 25c0f07b3ec5533c0e690e06198baa4300ee4a8c Mon Sep 17 00:00:00 2001 From: John Kacur Date: Wed, 7 Oct 2009 20:06:12 +0200 Subject: [PATCH] The BKL is not necessary in cpuid_open Most of the variables are local to the function. It IS possible that for struct cpuinfo_x86 *c c could point to the same area. However, this is used read only. Signed-off-by: John Kacur --- arch/x86/kernel/cpuid.c | 3 --- 1 files changed, 0 insertions(+), 3 deletions(-) diff --git a/arch/x86/kernel/cpuid.c b/arch/x86/kernel/cpuid.c index 6a52d4b..8bb8401 100644 --- a/arch/x86/kernel/cpuid.c +++ b/arch/x86/kernel/cpuid.c @@ -118,8 +118,6 @@ static int cpuid_open(struct inode *inode, struct file *file) struct cpuinfo_x86 *c; int ret = 0; - lock_kernel(); - cpu = iminor(file->f_path.dentry->d_inode); if (cpu >= nr_cpu_ids || !cpu_online(cpu)) { ret = -ENXIO; /* No such CPU */ @@ -129,7 +127,6 @@ static int cpuid_open(struct inode *inode, struct file *file) if (c->cpuid_level < 0) ret = -EIO; /* CPUID not supported */ out: - unlock_kernel(); return ret; } -- 1.6.0.6 -- 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/