Re: [patch] Re: problem with "sched: revert back to per-rqvruntime"?

From: Mike Galbraith
Date: Fri Jan 02 2009 - 06:16:56 EST


On Thu, 2009-01-01 at 18:14 -0600, Jayson King wrote:

> Still works OK for me. You may add, if you like:
>
> Tested-By: Jayson King <dev@xxxxxxxxxxxxxx>

Actually, I prefer the below. Everything in one spot and obvious.

Impact: bug fixlet.

Fix sched_slice() to emit a sane result whether a task is currently enqueued or not.

Signed-off-by: Mike Galbraith <efault@xxxxxx>

kernel/sched_fair.c | 30 ++++++++++++------------------
1 files changed, 12 insertions(+), 18 deletions(-)

diff --git a/kernel/sched_fair.c b/kernel/sched_fair.c
index 5ad4440..1a35bad 100644
--- a/kernel/sched_fair.c
+++ b/kernel/sched_fair.c
@@ -386,20 +386,6 @@ int sched_nr_latency_handler(struct ctl_table *table, int write,
#endif

/*
- * delta *= P[w / rw]
- */
-static inline unsigned long
-calc_delta_weight(unsigned long delta, struct sched_entity *se)
-{
- for_each_sched_entity(se) {
- delta = calc_delta_mine(delta,
- se->load.weight, &cfs_rq_of(se)->load);
- }
-
- return delta;
-}
-
-/*
* delta /= w
*/
static inline unsigned long
@@ -440,12 +426,20 @@ static u64 __sched_period(unsigned long nr_running)
*/
static u64 sched_slice(struct cfs_rq *cfs_rq, struct sched_entity *se)
{
- unsigned long nr_running = cfs_rq->nr_running;
+ u64 slice = __sched_period(cfs_rq->nr_running + !se->on_rq);
+
+ for_each_sched_entity(se) {
+ struct load_weight *load = &cfs_rq->load;

- if (unlikely(!se->on_rq))
- nr_running++;
+ if (unlikely(!se->on_rq)) {
+ struct load_weight lw = cfs_rq->load;

- return calc_delta_weight(__sched_period(nr_running), se);
+ update_load_add(&lw, se->load.weight);
+ load = &lw;
+ }
+ slice = calc_delta_mine(slice, se->load.weight, load);
+ }
+ return slice;
}

/*


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