On Tue, 26 Jun 2012 02:36:27 +0400
Glauber Costa [off-list ref] wrote:

On 06/25/2012 10:29 PM, Tejun Heo wrote:

quoted

Feeling like a nit pervert but..

On Mon, Jun 25, 2012 at 06:15:26PM +0400, Glauber Costa wrote:

quoted

@@ -287,7 +287,11 @@ struct mem_cgroup {
  	 * Should the accounting and control be hierarchical, per subtree?
  	 */
  	bool use_hierarchy;
-	bool kmem_accounted;
+	/*
+	 * bit0: accounted by this cgroup
+	 * bit1: accounted by a parent.
+	 */
+	volatile unsigned long kmem_accounted;

Is the volatile declaration really necessary?  Why is it necessary?
Why no comment explaining it?

Seems to be required by set_bit and friends. gcc will complain if it is 
not volatile (take a look at the bit function headers)

That would be a broken gcc.  We run test_bit()/set_bit() and friends
against plain old `unsigned long' in thousands of places.  There's
nothing special about this one!


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