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authorDmitry Adamushko <dmitry.adamushko@gmail.com>2007-10-15 17:00:07 +0200
committerIngo Molnar <mingo@elte.hu>2007-10-15 17:00:07 +0200
commit30cfdcfc5f180fc21a3dad6ae3b7b2a9ee112186 (patch)
tree7178cde2a1d2b924cc0b66031f4eb02482fe54c2 /kernel/sched_fair.c
parent7074badbcb4212d404a243e5c50efeb778ec3fc6 (diff)
sched: do not keep current in the tree and get rid of sched_entity::fair_key
Get rid of 'sched_entity::fair_key'. As a side effect, 'current' is not kept withing the tree for SCHED_NORMAL/BATCH tasks anymore. This simplifies some parts of code (e.g. entity_tick() and yield_task_fair()) and also somewhat optimizes them (e.g. a single update_curr() now vs. dequeue/enqueue() before in entity_tick()). Signed-off-by: Dmitry Adamushko <dmitry.adamushko@gmail.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Diffstat (limited to 'kernel/sched_fair.c')
-rw-r--r--kernel/sched_fair.c54
1 files changed, 35 insertions, 19 deletions
diff --git a/kernel/sched_fair.c b/kernel/sched_fair.c
index 144f3ef97380..b9e426a8a09f 100644
--- a/kernel/sched_fair.c
+++ b/kernel/sched_fair.c
@@ -139,7 +139,7 @@ set_leftmost(struct cfs_rq *cfs_rq, struct rb_node *leftmost)
static inline s64
entity_key(struct cfs_rq *cfs_rq, struct sched_entity *se)
{
- return se->fair_key - cfs_rq->min_vruntime;
+ return se->vruntime - cfs_rq->min_vruntime;
}
/*
@@ -181,9 +181,6 @@ __enqueue_entity(struct cfs_rq *cfs_rq, struct sched_entity *se)
rb_link_node(&se->run_node, parent, link);
rb_insert_color(&se->run_node, &cfs_rq->tasks_timeline);
- update_load_add(&cfs_rq->load, se->load.weight);
- cfs_rq->nr_running++;
- se->on_rq = 1;
}
static void
@@ -193,9 +190,6 @@ __dequeue_entity(struct cfs_rq *cfs_rq, struct sched_entity *se)
set_leftmost(cfs_rq, rb_next(&se->run_node));
rb_erase(&se->run_node, &cfs_rq->tasks_timeline);
- update_load_sub(&cfs_rq->load, se->load.weight);
- cfs_rq->nr_running--;
- se->on_rq = 0;
}
static inline struct rb_node *first_fair(struct cfs_rq *cfs_rq)
@@ -341,10 +335,6 @@ static void update_stats_enqueue(struct cfs_rq *cfs_rq, struct sched_entity *se)
*/
if (se != cfs_rq->curr)
update_stats_wait_start(cfs_rq, se);
- /*
- * Update the key:
- */
- se->fair_key = se->vruntime;
}
static void
@@ -392,6 +382,22 @@ update_stats_curr_end(struct cfs_rq *cfs_rq, struct sched_entity *se)
* Scheduling class queueing methods:
*/
+static void
+account_entity_enqueue(struct cfs_rq *cfs_rq, struct sched_entity *se)
+{
+ update_load_add(&cfs_rq->load, se->load.weight);
+ cfs_rq->nr_running++;
+ se->on_rq = 1;
+}
+
+static void
+account_entity_dequeue(struct cfs_rq *cfs_rq, struct sched_entity *se)
+{
+ update_load_sub(&cfs_rq->load, se->load.weight);
+ cfs_rq->nr_running--;
+ se->on_rq = 0;
+}
+
static void enqueue_sleeper(struct cfs_rq *cfs_rq, struct sched_entity *se)
{
#ifdef CONFIG_SCHEDSTATS
@@ -479,7 +485,9 @@ enqueue_entity(struct cfs_rq *cfs_rq, struct sched_entity *se, int wakeup)
}
update_stats_enqueue(cfs_rq, se);
- __enqueue_entity(cfs_rq, se);
+ if (se != cfs_rq->curr)
+ __enqueue_entity(cfs_rq, se);
+ account_entity_enqueue(cfs_rq, se);
}
static void
@@ -498,7 +506,9 @@ dequeue_entity(struct cfs_rq *cfs_rq, struct sched_entity *se, int sleep)
}
}
#endif
- __dequeue_entity(cfs_rq, se);
+ if (se != cfs_rq->curr)
+ __dequeue_entity(cfs_rq, se);
+ account_entity_dequeue(cfs_rq, se);
}
/*
@@ -544,6 +554,10 @@ static struct sched_entity *pick_next_entity(struct cfs_rq *cfs_rq)
{
struct sched_entity *se = __pick_next_entity(cfs_rq);
+ /* 'current' is not kept within the tree. */
+ if (se)
+ __dequeue_entity(cfs_rq, se);
+
set_next_entity(cfs_rq, se);
return se;
@@ -560,19 +574,20 @@ static void put_prev_entity(struct cfs_rq *cfs_rq, struct sched_entity *prev)
update_stats_curr_end(cfs_rq, prev);
- if (prev->on_rq)
+ if (prev->on_rq) {
update_stats_wait_start(cfs_rq, prev);
+ /* Put 'current' back into the tree. */
+ __enqueue_entity(cfs_rq, prev);
+ }
cfs_rq->curr = NULL;
}
static void entity_tick(struct cfs_rq *cfs_rq, struct sched_entity *curr)
{
/*
- * Dequeue and enqueue the task to update its
- * position within the tree:
+ * Update run-time statistics of the 'current'.
*/
- dequeue_entity(cfs_rq, curr, 0);
- enqueue_entity(cfs_rq, curr, 0);
+ update_curr(cfs_rq);
if (cfs_rq->nr_running > 1)
check_preempt_tick(cfs_rq, curr);
@@ -749,7 +764,7 @@ static void yield_task_fair(struct rq *rq, struct task_struct *p)
/*
* Minimally necessary key value to be last in the tree:
*/
- se->fair_key = rightmost->fair_key + 1;
+ se->vruntime = rightmost->vruntime + 1;
if (cfs_rq->rb_leftmost == &se->run_node)
cfs_rq->rb_leftmost = rb_next(&se->run_node);
@@ -965,6 +980,7 @@ static void task_new_fair(struct rq *rq, struct task_struct *p)
update_stats_enqueue(cfs_rq, se);
__enqueue_entity(cfs_rq, se);
+ account_entity_enqueue(cfs_rq, se);
resched_task(rq->curr);
}