Commit b29c617a authored Dec 06, 2010 by Christoph Lameter Committed by Tejun Heo Dec 17, 2010

random: Use this_cpu_inc_return



__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>
Acked-by: H. Peter Anvin <hpa@zytor.com>
Signed-off-by: Christoph Lameter <cl@linux.com>
Signed-off-by: Tejun Heo <tj@kernel.org>

parent ee1be862

drivers/char/random.c

+1 −1

Original line number	Diff line number	Diff line
		@@ -626,7 +626,7 @@ static void add_timer_randomness(struct timer_rand_state *state, unsigned num)
		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;