sched: optimize calc_delta_mine()

Joel noticed that the !lw->inv_weight contition isn't unlikely anymore so
remove the unlikely annotation. Also, remove the two div64_u64() inv_weight
calculations, which makes them rely on the calc_delta_mine() path as well.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
CC: Joel Schopp <jschopp@austin.ibm.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

diff --git a/kernel/sched.c b/kernel/sched.c
index 34bcc5bc120e5f2da970e180dfaf65d73b80dc7d..00c1ba706a5a36406555f70a31fd8636292af7d1 100644 (file)
--- a/kernel/sched.c
+++ b/kernel/sched.c
@@ -1438,8 +1438,8 @@ calc_delta_mine(unsigned long delta_exec, unsigned long weight,
 {
        u64 tmp;
 
-       if (unlikely(!lw->inv_weight))
-               lw->inv_weight = (WMULT_CONST-lw->weight/2) / (lw->weight+1);
+       if (!lw->inv_weight)
+               lw->inv_weight = 1 + (WMULT_CONST-lw->weight/2)/(lw->weight+1);
 
        tmp = (u64)delta_exec * weight;
        /*
@@ -8025,7 +8025,7 @@ static void init_tg_cfs_entry(struct task_group *tg, struct cfs_rq *cfs_rq,
 
        se->my_q = cfs_rq;
        se->load.weight = tg->shares;
-       se->load.inv_weight = div64_u64(1ULL<<32, se->load.weight);
+       se->load.inv_weight = 0;
        se->parent = parent;
 }
 #endif
@@ -8692,7 +8692,7 @@ static void __set_se_shares(struct sched_entity *se, unsigned long shares)
                dequeue_entity(cfs_rq, se, 0);
 
        se->load.weight = shares;
-       se->load.inv_weight = div64_u64((1ULL<<32), shares);
+       se->load.inv_weight = 0;
 
        if (on_rq)
                enqueue_entity(cfs_rq, se, 0);