From 2161573ecd6931565936cb66793b2d2bf805c088 Mon Sep 17 00:00:00 2001 From: Davidlohr Bueso Date: Fri, 8 Sep 2017 16:14:58 -0700 Subject: sched/deadline: replace earliest dl and rq leftmost caching ... with the generic rbtree flavor instead. No changes in semantics whatsoever. Link: http://lkml.kernel.org/r/20170719014603.19029-9-dave@stgolabs.net Signed-off-by: Davidlohr Bueso Acked-by: Peter Zijlstra (Intel) Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- kernel/sched/deadline.c | 50 +++++++++++++++++++------------------------------ kernel/sched/sched.h | 6 ++---- 2 files changed, 21 insertions(+), 35 deletions(-) diff --git a/kernel/sched/deadline.c b/kernel/sched/deadline.c index 9e38df7649f4..0191ec7667c3 100644 --- a/kernel/sched/deadline.c +++ b/kernel/sched/deadline.c @@ -296,7 +296,7 @@ static inline int is_leftmost(struct task_struct *p, struct dl_rq *dl_rq) { struct sched_dl_entity *dl_se = &p->dl; - return dl_rq->rb_leftmost == &dl_se->rb_node; + return dl_rq->root.rb_leftmost == &dl_se->rb_node; } void init_dl_bandwidth(struct dl_bandwidth *dl_b, u64 period, u64 runtime) @@ -320,7 +320,7 @@ void init_dl_bw(struct dl_bw *dl_b) void init_dl_rq(struct dl_rq *dl_rq) { - dl_rq->rb_root = RB_ROOT; + dl_rq->root = RB_ROOT_CACHED; #ifdef CONFIG_SMP /* zero means no -deadline tasks */ @@ -328,7 +328,7 @@ void init_dl_rq(struct dl_rq *dl_rq) dl_rq->dl_nr_migratory = 0; dl_rq->overloaded = 0; - dl_rq->pushable_dl_tasks_root = RB_ROOT; + dl_rq->pushable_dl_tasks_root = RB_ROOT_CACHED; #else init_dl_bw(&dl_rq->dl_bw); #endif @@ -410,10 +410,10 @@ static void dec_dl_migration(struct sched_dl_entity *dl_se, struct dl_rq *dl_rq) static void enqueue_pushable_dl_task(struct rq *rq, struct task_struct *p) { struct dl_rq *dl_rq = &rq->dl; - struct rb_node **link = &dl_rq->pushable_dl_tasks_root.rb_node; + struct rb_node **link = &dl_rq->pushable_dl_tasks_root.rb_root.rb_node; struct rb_node *parent = NULL; struct task_struct *entry; - int leftmost = 1; + bool leftmost = true; BUG_ON(!RB_EMPTY_NODE(&p->pushable_dl_tasks)); @@ -425,17 +425,16 @@ static void enqueue_pushable_dl_task(struct rq *rq, struct task_struct *p) link = &parent->rb_left; else { link = &parent->rb_right; - leftmost = 0; + leftmost = false; } } - if (leftmost) { - dl_rq->pushable_dl_tasks_leftmost = &p->pushable_dl_tasks; + if (leftmost) dl_rq->earliest_dl.next = p->dl.deadline; - } rb_link_node(&p->pushable_dl_tasks, parent, link); - rb_insert_color(&p->pushable_dl_tasks, &dl_rq->pushable_dl_tasks_root); + rb_insert_color_cached(&p->pushable_dl_tasks, + &dl_rq->pushable_dl_tasks_root, leftmost); } static void dequeue_pushable_dl_task(struct rq *rq, struct task_struct *p) @@ -445,24 +444,23 @@ static void dequeue_pushable_dl_task(struct rq *rq, struct task_struct *p) if (RB_EMPTY_NODE(&p->pushable_dl_tasks)) return; - if (dl_rq->pushable_dl_tasks_leftmost == &p->pushable_dl_tasks) { + if (dl_rq->pushable_dl_tasks_root.rb_leftmost == &p->pushable_dl_tasks) { struct rb_node *next_node; next_node = rb_next(&p->pushable_dl_tasks); - dl_rq->pushable_dl_tasks_leftmost = next_node; if (next_node) { dl_rq->earliest_dl.next = rb_entry(next_node, struct task_struct, pushable_dl_tasks)->dl.deadline; } } - rb_erase(&p->pushable_dl_tasks, &dl_rq->pushable_dl_tasks_root); + rb_erase_cached(&p->pushable_dl_tasks, &dl_rq->pushable_dl_tasks_root); RB_CLEAR_NODE(&p->pushable_dl_tasks); } static inline int has_pushable_dl_tasks(struct rq *rq) { - return !RB_EMPTY_ROOT(&rq->dl.pushable_dl_tasks_root); + return !RB_EMPTY_ROOT(&rq->dl.pushable_dl_tasks_root.rb_root); } static int push_dl_task(struct rq *rq); @@ -1266,7 +1264,7 @@ static void dec_dl_deadline(struct dl_rq *dl_rq, u64 deadline) dl_rq->earliest_dl.next = 0; cpudl_clear(&rq->rd->cpudl, rq->cpu); } else { - struct rb_node *leftmost = dl_rq->rb_leftmost; + struct rb_node *leftmost = dl_rq->root.rb_leftmost; struct sched_dl_entity *entry; entry = rb_entry(leftmost, struct sched_dl_entity, rb_node); @@ -1313,7 +1311,7 @@ void dec_dl_tasks(struct sched_dl_entity *dl_se, struct dl_rq *dl_rq) static void __enqueue_dl_entity(struct sched_dl_entity *dl_se) { struct dl_rq *dl_rq = dl_rq_of_se(dl_se); - struct rb_node **link = &dl_rq->rb_root.rb_node; + struct rb_node **link = &dl_rq->root.rb_root.rb_node; struct rb_node *parent = NULL; struct sched_dl_entity *entry; int leftmost = 1; @@ -1331,11 +1329,8 @@ static void __enqueue_dl_entity(struct sched_dl_entity *dl_se) } } - if (leftmost) - dl_rq->rb_leftmost = &dl_se->rb_node; - rb_link_node(&dl_se->rb_node, parent, link); - rb_insert_color(&dl_se->rb_node, &dl_rq->rb_root); + rb_insert_color_cached(&dl_se->rb_node, &dl_rq->root, leftmost); inc_dl_tasks(dl_se, dl_rq); } @@ -1347,14 +1342,7 @@ static void __dequeue_dl_entity(struct sched_dl_entity *dl_se) if (RB_EMPTY_NODE(&dl_se->rb_node)) return; - if (dl_rq->rb_leftmost == &dl_se->rb_node) { - struct rb_node *next_node; - - next_node = rb_next(&dl_se->rb_node); - dl_rq->rb_leftmost = next_node; - } - - rb_erase(&dl_se->rb_node, &dl_rq->rb_root); + rb_erase_cached(&dl_se->rb_node, &dl_rq->root); RB_CLEAR_NODE(&dl_se->rb_node); dec_dl_tasks(dl_se, dl_rq); @@ -1647,7 +1635,7 @@ static void start_hrtick_dl(struct rq *rq, struct task_struct *p) static struct sched_dl_entity *pick_next_dl_entity(struct rq *rq, struct dl_rq *dl_rq) { - struct rb_node *left = dl_rq->rb_leftmost; + struct rb_node *left = rb_first_cached(&dl_rq->root); if (!left) return NULL; @@ -1771,7 +1759,7 @@ static int pick_dl_task(struct rq *rq, struct task_struct *p, int cpu) */ static struct task_struct *pick_earliest_pushable_dl_task(struct rq *rq, int cpu) { - struct rb_node *next_node = rq->dl.pushable_dl_tasks_leftmost; + struct rb_node *next_node = rq->dl.pushable_dl_tasks_root.rb_leftmost; struct task_struct *p = NULL; if (!has_pushable_dl_tasks(rq)) @@ -1945,7 +1933,7 @@ static struct task_struct *pick_next_pushable_dl_task(struct rq *rq) if (!has_pushable_dl_tasks(rq)) return NULL; - p = rb_entry(rq->dl.pushable_dl_tasks_leftmost, + p = rb_entry(rq->dl.pushable_dl_tasks_root.rb_leftmost, struct task_struct, pushable_dl_tasks); BUG_ON(rq->cpu != task_cpu(p)); diff --git a/kernel/sched/sched.h b/kernel/sched/sched.h index c30c57563dbc..746ac78ff492 100644 --- a/kernel/sched/sched.h +++ b/kernel/sched/sched.h @@ -549,8 +549,7 @@ struct rt_rq { /* Deadline class' related fields in a runqueue */ struct dl_rq { /* runqueue is an rbtree, ordered by deadline */ - struct rb_root rb_root; - struct rb_node *rb_leftmost; + struct rb_root_cached root; unsigned long dl_nr_running; @@ -574,8 +573,7 @@ struct dl_rq { * an rb-tree, ordered by tasks' deadlines, with caching * of the leftmost (earliest deadline) element. */ - struct rb_root pushable_dl_tasks_root; - struct rb_node *pushable_dl_tasks_leftmost; + struct rb_root_cached pushable_dl_tasks_root; #else struct dl_bw dl_bw; #endif -- cgit v1.2.3