sched: remove do_div() from __sched_slice()
Yanmin Zhang noticed a nice optimization:
p = l * nr / nl, nl = l/g -> p = g * nr
which eliminates a do_div() from __sched_period().
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
diff --git a/kernel/sched_fair.c b/kernel/sched_fair.c
index 2208692..10aa6e1 100644
--- a/kernel/sched_fair.c
+++ b/kernel/sched_fair.c
@@ -248,8 +248,8 @@
unsigned long nr_latency = sched_nr_latency;
if (unlikely(nr_running > nr_latency)) {
+ period = sysctl_sched_min_granularity;
period *= nr_running;
- do_div(period, nr_latency);
}
return period;