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Date: Tue, 16 Jan 2007 18:06:00 -0000
From: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
To: Ingo Molnar <mingo@redhat.com>
Cc: Andrew Morton <akpm@osdl.org>,   Greg Kroah-Hartman <gregkh@suse.de>,   Christoph Hellwig <hch@infradead.org>, linux-kernel@vger.kernel.org,   ltt-dev@shafik.org, "Martin J. Bligh" <mbligh@mbligh.org>,   Douglas Niehaus <niehaus@eecs.ku.edu>, systemtap@sources.redhat.com,   Thomas Gleixner <tglx@linutronix.de>,   Richard J Moore <richardj_moore@uk.ibm.com>
Subject: [PATCH 1/2] lockdep missing barrier()
Message-ID: <20070116175624.GA16022@Krystal>
References: <20061220235216.GA28643@Krystal> <OFAB3D8A6C.1643F2D3-ON80257262.000581E4-80257262.00088F04@uk.ibm.com>
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This patch adds a barrier() to lockdep.c lockdep_recursion updates. This
variable behaves like the preemption count and should therefore use similar
memory barriers.

This patch applies on 2.6.20-rc4-git3.

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>

--- a/kernel/lockdep.c
+++ b/kernel/lockdep.c
@@ -166,12 +166,14 @@ static struct list_head chainhash_table[CHAINHASH_SIZE];
 void lockdep_off(void)
 {
 	current->lockdep_recursion++;
+	barrier();
 }
 
 EXPORT_SYMBOL(lockdep_off);
 
 void lockdep_on(void)
 {
+	barrier();
 	current->lockdep_recursion--;
 }

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