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authorDavidlohr Bueso <dave@stgolabs.net>2017-09-08 16:14:55 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2017-09-08 18:26:48 -0700
commitbfb068892d30dcf0a32b89302fe293347adeaaaa (patch)
tree89d37a18423927ad7efc9f923f0f350e613bb26f /kernel/sched
parentb10d43f9898e0b56f6cf2375093dbd2c5db54486 (diff)
sched/fair: replace cfs_rq->rb_leftmost
... with the generic rbtree flavor instead. No changes in semantics whatsoever. Link: http://lkml.kernel.org/r/20170719014603.19029-8-dave@stgolabs.net Signed-off-by: Davidlohr Bueso <dbueso@suse.de> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'kernel/sched')
-rw-r--r--kernel/sched/debug.c2
-rw-r--r--kernel/sched/fair.c39
-rw-r--r--kernel/sched/sched.h3
3 files changed, 15 insertions, 29 deletions
diff --git a/kernel/sched/debug.c b/kernel/sched/debug.c
index 4a23bbc3111b..8e536d963652 100644
--- a/kernel/sched/debug.c
+++ b/kernel/sched/debug.c
@@ -530,7 +530,7 @@ void print_cfs_rq(struct seq_file *m, int cpu, struct cfs_rq *cfs_rq)
SPLIT_NS(cfs_rq->exec_clock));
raw_spin_lock_irqsave(&rq->lock, flags);
- if (cfs_rq->rb_leftmost)
+ if (rb_first_cached(&cfs_rq->tasks_timeline))
MIN_vruntime = (__pick_first_entity(cfs_rq))->vruntime;
last = __pick_last_entity(cfs_rq);
if (last)
diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index 8bc0a883d190..a5d83ed8dd82 100644
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -513,6 +513,7 @@ static inline int entity_before(struct sched_entity *a,
static void update_min_vruntime(struct cfs_rq *cfs_rq)
{
struct sched_entity *curr = cfs_rq->curr;
+ struct rb_node *leftmost = rb_first_cached(&cfs_rq->tasks_timeline);
u64 vruntime = cfs_rq->min_vruntime;
@@ -523,10 +524,9 @@ static void update_min_vruntime(struct cfs_rq *cfs_rq)
curr = NULL;
}
- if (cfs_rq->rb_leftmost) {
- struct sched_entity *se = rb_entry(cfs_rq->rb_leftmost,
- struct sched_entity,
- run_node);
+ if (leftmost) { /* non-empty tree */
+ struct sched_entity *se;
+ se = rb_entry(leftmost, struct sched_entity, run_node);
if (!curr)
vruntime = se->vruntime;
@@ -547,10 +547,10 @@ static void update_min_vruntime(struct cfs_rq *cfs_rq)
*/
static void __enqueue_entity(struct cfs_rq *cfs_rq, struct sched_entity *se)
{
- struct rb_node **link = &cfs_rq->tasks_timeline.rb_node;
+ struct rb_node **link = &cfs_rq->tasks_timeline.rb_root.rb_node;
struct rb_node *parent = NULL;
struct sched_entity *entry;
- int leftmost = 1;
+ bool leftmost = true;
/*
* Find the right place in the rbtree:
@@ -566,36 +566,23 @@ static void __enqueue_entity(struct cfs_rq *cfs_rq, struct sched_entity *se)
link = &parent->rb_left;
} else {
link = &parent->rb_right;
- leftmost = 0;
+ leftmost = false;
}
}
- /*
- * Maintain a cache of leftmost tree entries (it is frequently
- * used):
- */
- if (leftmost)
- cfs_rq->rb_leftmost = &se->run_node;
-
rb_link_node(&se->run_node, parent, link);
- rb_insert_color(&se->run_node, &cfs_rq->tasks_timeline);
+ rb_insert_color_cached(&se->run_node,
+ &cfs_rq->tasks_timeline, leftmost);
}
static void __dequeue_entity(struct cfs_rq *cfs_rq, struct sched_entity *se)
{
- if (cfs_rq->rb_leftmost == &se->run_node) {
- struct rb_node *next_node;
-
- next_node = rb_next(&se->run_node);
- cfs_rq->rb_leftmost = next_node;
- }
-
- rb_erase(&se->run_node, &cfs_rq->tasks_timeline);
+ rb_erase_cached(&se->run_node, &cfs_rq->tasks_timeline);
}
struct sched_entity *__pick_first_entity(struct cfs_rq *cfs_rq)
{
- struct rb_node *left = cfs_rq->rb_leftmost;
+ struct rb_node *left = rb_first_cached(&cfs_rq->tasks_timeline);
if (!left)
return NULL;
@@ -616,7 +603,7 @@ static struct sched_entity *__pick_next_entity(struct sched_entity *se)
#ifdef CONFIG_SCHED_DEBUG
struct sched_entity *__pick_last_entity(struct cfs_rq *cfs_rq)
{
- struct rb_node *last = rb_last(&cfs_rq->tasks_timeline);
+ struct rb_node *last = rb_last(&cfs_rq->tasks_timeline.rb_root);
if (!last)
return NULL;
@@ -9312,7 +9299,7 @@ static void set_curr_task_fair(struct rq *rq)
void init_cfs_rq(struct cfs_rq *cfs_rq)
{
- cfs_rq->tasks_timeline = RB_ROOT;
+ cfs_rq->tasks_timeline = RB_ROOT_CACHED;
cfs_rq->min_vruntime = (u64)(-(1LL << 20));
#ifndef CONFIG_64BIT
cfs_rq->min_vruntime_copy = cfs_rq->min_vruntime;
diff --git a/kernel/sched/sched.h b/kernel/sched/sched.h
index 6ed7962dc896..c30c57563dbc 100644
--- a/kernel/sched/sched.h
+++ b/kernel/sched/sched.h
@@ -426,8 +426,7 @@ struct cfs_rq {
u64 min_vruntime_copy;
#endif
- struct rb_root tasks_timeline;
- struct rb_node *rb_leftmost;
+ struct rb_root_cached tasks_timeline;
/*
* 'curr' points to currently running entity on this cfs_rq.