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 <jkacur@redhat.com>
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 <jkacur@redhat.com>
---
 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();