sched: clean up the wakeup preempt check, #2

clean up the preemption check to not use unnecessary 64-bit
variables. This improves code size:

   text    data     bss     dec     hex filename
  44227    3326      36   47589    b9e5 sched.o.before
  44201    3326      36   47563    b9cb sched.o.after

Signed-off-by: Ingo Molnar <mingo@elte.hu>

diff --git a/kernel/sched_fair.c b/kernel/sched_fair.c
index d558716..6c36147 100644 (file)
--- a/kernel/sched_fair.c
+++ b/kernel/sched_fair.c
@@ -837,7 +837,7 @@ static void check_preempt_wakeup(struct rq *rq, struct task_struct *p)
        struct task_struct *curr = rq->curr;
        struct cfs_rq *cfs_rq = task_cfs_rq(curr);
        struct sched_entity *se = &curr->se, *pse = &p->se;
-       s64 delta, gran;
+       unsigned long gran;
 
        if (unlikely(rt_prio(p->prio))) {
                update_rq_clock(rq);
@@ -860,12 +860,11 @@ static void check_preempt_wakeup(struct rq *rq, struct task_struct *p)
                pse = parent_entity(pse);
        }
 
-       delta = se->vruntime - pse->vruntime;
        gran = sysctl_sched_wakeup_granularity;
        if (unlikely(se->load.weight != NICE_0_LOAD))
                gran = calc_delta_fair(gran, &se->load);
 
-       if (delta > gran)
+       if (pse->vruntime + gran < se->vruntime)
                resched_task(curr);
 }