[cpuops inc_return V1 8/9] random: Use this_cpu_inc_return

[Christoph Lameter <cl@linux.com>]

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__this_cpu_inc can create a single instruction to do the same as
__get_cpu_var()++.

Cc: Richard Kennedy <richard@rsk.demon.co.uk>
Cc: Matt Mackall <mpm@selenic.com>
Signed-off-by: Christoph Lameter <cl@linux.com>

---
 drivers/char/random.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

Index: linux-2.6/drivers/char/random.c
===================================================================
--- linux-2.6.orig/drivers/char/random.c	2010-12-06 11:01:06.000000000 -0600
+++ linux-2.6/drivers/char/random.c	2010-12-06 11:19:38.000000000 -0600
@@ -626,7 +626,7 @@ static void add_timer_randomness(struct
 	preempt_disable();
 	/* if over the trickle threshold, use only 1 in 4096 samples */
 	if (input_pool.entropy_count > trickle_thresh &&
-	    (__get_cpu_var(trickle_count)++ & 0xfff))
+	    ((__this_cpu_inc_return(trickle_count) - 1) & 0xfff))
 		goto out;
 
 	sample.jiffies = jiffies;