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 <[email protected]>
Cc: Matt Mackall <[email protected]>
Acked-by: H. Peter Anvin <[email protected]>
Signed-off-by: Christoph Lameter <[email protected]>
Signed-off-by: Tejun Heo <[email protected]>
This commit is contained in:
Christoph Lameter 2010-12-06 11:40:06 -06:00 • committed by Tejun Heo
commit b29c617af3

View file

@ -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;