sched: clean up calc_weighted()

clean up calc_weighted() - we always use the normalized shift so
it's not needed to pass that in. Also, push the non-nice0 branch
into the function.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Mike Galbraith <efault@gmx.de>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>

1 files changed, 8 insertions, 23 deletions

diff --git a/kernel/sched_fair.c b/kernel/sched_fair.c
index 91a227b436ee..b46f8078e78f 100644
--- a/kernel/sched_fair.c
+++ b/kernel/sched_fair.c
@@ -397,27 +397,16 @@ update_stats_wait_start(struct cfs_rq *cfs_rq, struct sched_entity *se)
         schedstat_set(se->wait_start, rq_of(cfs_rq)->clock);
 }
 
-/*
- * We calculate fair deltas here, so protect against the random effects
- * of a multiplication overflow by capping it to the runtime limit:
- */
-#if BITS_PER_LONG == 32
 static inline unsigned long
-calc_weighted(unsigned long delta, unsigned long weight, int shift)
+calc_weighted(unsigned long delta, struct sched_entity *se)
 {
-        u64 tmp = (u64)delta * weight >> shift;
+        unsigned long weight = se->load.weight;
 
-        if (unlikely(tmp > sysctl_sched_runtime_limit*2))
-                return sysctl_sched_runtime_limit*2;
-        return tmp;
+        if (unlikely(weight != NICE_0_LOAD))
+                return (u64)delta * se->load.weight >> NICE_0_SHIFT;
+        else
+                return delta;
 }
-#else
-static inline unsigned long
-calc_weighted(unsigned long delta, unsigned long weight, int shift)
-{
-        return delta * weight >> shift;
-}
-#endif
 
 /*
  * Task is being enqueued - update stats:
@@ -469,9 +458,7 @@ __update_stats_wait_end(struct cfs_rq *cfs_rq, struct sched_entity *se,
         schedstat_set(se->wait_max, max(se->wait_max,
                         rq_of(cfs_rq)->clock - se->wait_start));
 
-        if (unlikely(se->load.weight != NICE_0_LOAD))
-                delta_fair = calc_weighted(delta_fair, se->load.weight,
-                                                        NICE_0_SHIFT);
+        delta_fair = calc_weighted(delta_fair, se);
 
         add_wait_runtime(cfs_rq, se, delta_fair);
 }
@@ -554,9 +541,7 @@ static void __enqueue_sleeper(struct cfs_rq *cfs_rq, struct sched_entity *se,
                 delta_fair = div64_likely32((u64)delta_fair * load,
                                                 load + se->load.weight);
 
-        if (unlikely(se->load.weight != NICE_0_LOAD))
-                delta_fair = calc_weighted(delta_fair, se->load.weight,
-                                                        NICE_0_SHIFT);
+        delta_fair = calc_weighted(delta_fair, se);
 
         prev_runtime = se->wait_runtime;
         __add_wait_runtime(cfs_rq, se, delta_fair);