sched: Add enqueue/dequeue flags

In order to reduce the dependency on TASK_WAKING rework the enqueue
interface to support a proper flags field.

Replace the int wakeup, bool head arguments with an int flags argument
and create the following flags:

  ENQUEUE_WAKEUP - the enqueue is a wakeup of a sleeping task,
  ENQUEUE_WAKING - the enqueue has relative vruntime due to
                   having sched_class::task_waking() called,
  ENQUEUE_HEAD - the waking task should be places on the head
                 of the priority queue (where appropriate).

For symmetry also convert sched_class::dequeue() to a flags scheme.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <new-submission>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

1 files changed, 8 insertions, 17 deletions

diff --git a/kernel/sched_fair.c b/kernel/sched_fair.c
index 8a5e7632d09..88d3053ac7c 100644
--- a/kernel/sched_fair.c
+++ b/kernel/sched_fair.c
@@ -757,9 +757,6 @@ place_entity(struct cfs_rq *cfs_rq, struct sched_entity *se, int initial)
         se->vruntime = vruntime;
 }
 
-#define ENQUEUE_WAKEUP  1
-#define ENQUEUE_MIGRATE 2
-
 static void
 enqueue_entity(struct cfs_rq *cfs_rq, struct sched_entity *se, int flags)
 {
@@ -767,7 +764,7 @@ enqueue_entity(struct cfs_rq *cfs_rq, struct sched_entity *se, int flags)
          * Update the normalized vruntime before updating min_vruntime
          * through callig update_curr().
          */
-        if (!(flags & ENQUEUE_WAKEUP) || (flags & ENQUEUE_MIGRATE))
+        if (!(flags & ENQUEUE_WAKEUP) || (flags & ENQUEUE_WAKING))
                 se->vruntime += cfs_rq->min_vruntime;
 
         /*
@@ -803,7 +800,7 @@ static void clear_buddies(struct cfs_rq *cfs_rq, struct sched_entity *se)
 }
 
 static void
-dequeue_entity(struct cfs_rq *cfs_rq, struct sched_entity *se, int sleep)
+dequeue_entity(struct cfs_rq *cfs_rq, struct sched_entity *se, int flags)
 {
         /*
          * Update run-time statistics of the 'current'.
@@ -811,7 +808,7 @@ dequeue_entity(struct cfs_rq *cfs_rq, struct sched_entity *se, int sleep)
         update_curr(cfs_rq);
 
         update_stats_dequeue(cfs_rq, se);
-        if (sleep) {
+        if (flags & DEQUEUE_SLEEP) {
 #ifdef CONFIG_SCHEDSTATS
                 if (entity_is_task(se)) {
                         struct task_struct *tsk = task_of(se);
@@ -836,7 +833,7 @@ dequeue_entity(struct cfs_rq *cfs_rq, struct sched_entity *se, int sleep)
          * update can refer to the ->curr item and we need to reflect this
          * movement in our normalized position.
          */
-        if (!sleep)
+        if (!(flags & DEQUEUE_SLEEP))
                 se->vruntime -= cfs_rq->min_vruntime;
 }
 
@@ -1045,16 +1042,10 @@ static inline void hrtick_update(struct rq *rq)
  * then put the task into the rbtree:
  */
 static void
-enqueue_task_fair(struct rq *rq, struct task_struct *p, int wakeup, bool head)
+enqueue_task_fair(struct rq *rq, struct task_struct *p, int flags)
 {
         struct cfs_rq *cfs_rq;
         struct sched_entity *se = &p->se;
-        int flags = 0;
-
-        if (wakeup)
-                flags |= ENQUEUE_WAKEUP;
-        if (p->state == TASK_WAKING)
-                flags |= ENQUEUE_MIGRATE;
 
         for_each_sched_entity(se) {
                 if (se->on_rq)
@@ -1072,18 +1063,18 @@ enqueue_task_fair(struct rq *rq, struct task_struct *p, int wakeup, bool head)
  * decreased. We remove the task from the rbtree and
  * update the fair scheduling stats:
  */
-static void dequeue_task_fair(struct rq *rq, struct task_struct *p, int sleep)
+static void dequeue_task_fair(struct rq *rq, struct task_struct *p, int flags)
 {
         struct cfs_rq *cfs_rq;
         struct sched_entity *se = &p->se;
 
         for_each_sched_entity(se) {
                 cfs_rq = cfs_rq_of(se);
-                dequeue_entity(cfs_rq, se, sleep);
+                dequeue_entity(cfs_rq, se, flags);
                 /* Don't dequeue parent if it has other entities besides us */
                 if (cfs_rq->load.weight)
                         break;
-                sleep = 1;
+                flags |= DEQUEUE_SLEEP;
         }
 
         hrtick_update(rq);