From f6b53205e17c8ca481c69ed579a35a650a4b481a Mon Sep 17 00:00:00 2001 From: Dmitry Adamushko Date: Mon, 15 Oct 2007 17:00:08 +0200 Subject: [PATCH] sched: rework enqueue/dequeue_entity() to get rid of set_curr_task() rework enqueue/dequeue_entity() to get rid of sched_class::set_curr_task(). This simplifies sched_setscheduler(), rt_mutex_setprio() and sched_move_tasks(). text data bss dec hex filename 24330 2734 20 27084 69cc sched.o.before 24233 2730 20 26983 6967 sched.o.after Signed-off-by: Dmitry Adamushko Signed-off-by: Srivatsa Vaddagiri Signed-off-by: Ingo Molnar Signed-off-by: Peter Zijlstra Reviewed-by: Thomas Gleixner --- include/linux/sched.h | 1 - kernel/sched.c | 36 ++++++++------------------- kernel/sched_fair.c | 55 +++++++++++++++++++---------------------- kernel/sched_idletask.c | 5 ---- kernel/sched_rt.c | 5 ---- 5 files changed, 35 insertions(+), 67 deletions(-) diff --git a/include/linux/sched.h b/include/linux/sched.h index 66169005f0..abcb02738d 100644 --- a/include/linux/sched.h +++ b/include/linux/sched.h @@ -871,7 +871,6 @@ struct sched_class { struct sched_domain *sd, enum cpu_idle_type idle, int *all_pinned, int *this_best_prio); - void (*set_curr_task) (struct rq *rq); void (*task_tick) (struct rq *rq, struct task_struct *p); void (*task_new) (struct rq *rq, struct task_struct *p); }; diff --git a/kernel/sched.c b/kernel/sched.c index e1f784f4b4..72c936d3e3 100644 --- a/kernel/sched.c +++ b/kernel/sched.c @@ -3915,8 +3915,8 @@ EXPORT_SYMBOL(sleep_on_timeout); */ void rt_mutex_setprio(struct task_struct *p, int prio) { - int oldprio, on_rq, running; unsigned long flags; + int oldprio, on_rq; struct rq *rq; BUG_ON(prio < 0 || prio > MAX_PRIO); @@ -3926,12 +3926,8 @@ void rt_mutex_setprio(struct task_struct *p, int prio) oldprio = p->prio; on_rq = p->se.on_rq; - running = task_running(rq, p); - if (on_rq) { + if (on_rq) dequeue_task(rq, p, 0); - if (running) - p->sched_class->put_prev_task(rq, p); - } if (rt_prio(prio)) p->sched_class = &rt_sched_class; @@ -3941,15 +3937,13 @@ void rt_mutex_setprio(struct task_struct *p, int prio) p->prio = prio; if (on_rq) { - if (running) - p->sched_class->set_curr_task(rq); enqueue_task(rq, p, 0); /* * Reschedule if we are currently running on this runqueue and * our priority decreased, or if we are not currently running on * this runqueue and our priority is higher than the current's */ - if (running) { + if (task_running(rq, p)) { if (p->prio > oldprio) resched_task(rq->curr); } else { @@ -4155,7 +4149,7 @@ __setscheduler(struct rq *rq, struct task_struct *p, int policy, int prio) int sched_setscheduler(struct task_struct *p, int policy, struct sched_param *param) { - int retval, oldprio, oldpolicy = -1, on_rq, running; + int retval, oldprio, oldpolicy = -1, on_rq; unsigned long flags; struct rq *rq; @@ -4237,24 +4231,20 @@ recheck: } update_rq_clock(rq); on_rq = p->se.on_rq; - running = task_running(rq, p); - if (on_rq) { + if (on_rq) deactivate_task(rq, p, 0); - if (running) - p->sched_class->put_prev_task(rq, p); - } + oldprio = p->prio; __setscheduler(rq, p, policy, param->sched_priority); + if (on_rq) { - if (running) - p->sched_class->set_curr_task(rq); activate_task(rq, p, 0); /* * Reschedule if we are currently running on this runqueue and * our priority decreased, or if we are not currently running on * this runqueue and our priority is higher than the current's */ - if (running) { + if (task_running(rq, p)) { if (p->prio > oldprio) resched_task(rq->curr); } else { @@ -6855,19 +6845,13 @@ static void sched_move_task(struct container_subsys *ss, struct container *cont, running = task_running(rq, tsk); on_rq = tsk->se.on_rq; - if (on_rq) { + if (on_rq) dequeue_task(rq, tsk, 0); - if (unlikely(running)) - tsk->sched_class->put_prev_task(rq, tsk); - } set_task_cfs_rq(tsk); - if (on_rq) { - if (unlikely(running)) - tsk->sched_class->set_curr_task(rq); + if (on_rq) enqueue_task(rq, tsk, 0); - } done: task_rq_unlock(rq, &flags); diff --git a/kernel/sched_fair.c b/kernel/sched_fair.c index 4dd256d468..568e922255 100644 --- a/kernel/sched_fair.c +++ b/kernel/sched_fair.c @@ -472,8 +472,19 @@ place_entity(struct cfs_rq *cfs_rq, struct sched_entity *se, int initial) } static void -enqueue_entity(struct cfs_rq *cfs_rq, struct sched_entity *se, int wakeup) +enqueue_entity(struct cfs_rq *cfs_rq, struct sched_entity *se, + int wakeup, int set_curr) { + /* + * In case of the 'current'. + */ + if (unlikely(set_curr)) { + update_stats_curr_start(cfs_rq, se); + cfs_rq->curr = se; + account_entity_enqueue(cfs_rq, se); + return; + } + /* * Update the fair clock. */ @@ -485,8 +496,7 @@ enqueue_entity(struct cfs_rq *cfs_rq, struct sched_entity *se, int wakeup) } update_stats_enqueue(cfs_rq, se); - if (se != cfs_rq->curr) - __enqueue_entity(cfs_rq, se); + __enqueue_entity(cfs_rq, se); account_entity_enqueue(cfs_rq, se); } @@ -506,8 +516,12 @@ dequeue_entity(struct cfs_rq *cfs_rq, struct sched_entity *se, int sleep) } } #endif - if (se != cfs_rq->curr) + if (likely(se != cfs_rq->curr)) __dequeue_entity(cfs_rq, se); + else { + update_stats_curr_end(cfs_rq, se); + cfs_rq->curr = NULL; + } account_entity_dequeue(cfs_rq, se); } @@ -689,12 +703,17 @@ static void enqueue_task_fair(struct rq *rq, struct task_struct *p, int wakeup) { struct cfs_rq *cfs_rq; struct sched_entity *se = &p->se; + int set_curr = 0; + + /* Are we enqueuing the current task? */ + if (unlikely(task_running(rq, p))) + set_curr = 1; for_each_sched_entity(se) { if (se->on_rq) break; cfs_rq = cfs_rq_of(se); - enqueue_entity(cfs_rq, se, wakeup); + enqueue_entity(cfs_rq, se, wakeup, set_curr); } } @@ -742,7 +761,7 @@ static void yield_task_fair(struct rq *rq) * position within the tree: */ dequeue_entity(cfs_rq, se, 0); - enqueue_entity(cfs_rq, se, 0); + enqueue_entity(cfs_rq, se, 0, 1); return; } @@ -985,29 +1004,6 @@ static void task_new_fair(struct rq *rq, struct task_struct *p) resched_task(rq->curr); } -#ifdef CONFIG_FAIR_GROUP_SCHED -/* Account for a task changing its policy or group. - * - * This routine is mostly called to set cfs_rq->curr field when a task - * migrates between groups/classes. - */ -static void set_curr_task_fair(struct rq *rq) -{ - struct sched_entity *se = &rq->curr->se; - - for_each_sched_entity(se) - set_next_entity(cfs_rq_of(se), se); -} -#else -static void set_curr_task_fair(struct rq *rq) -{ - struct sched_entity *se = &rq->curr->se; - struct cfs_rq *cfs_rq = cfs_rq_of(se); - - cfs_rq->curr = se; -} -#endif - /* * All the scheduling class methods: */ @@ -1023,7 +1019,6 @@ struct sched_class fair_sched_class __read_mostly = { .load_balance = load_balance_fair, - .set_curr_task = set_curr_task_fair, .task_tick = task_tick_fair, .task_new = task_new_fair, }; diff --git a/kernel/sched_idletask.c b/kernel/sched_idletask.c index 5ebf829cdd..3503fb2d9f 100644 --- a/kernel/sched_idletask.c +++ b/kernel/sched_idletask.c @@ -50,10 +50,6 @@ static void task_tick_idle(struct rq *rq, struct task_struct *curr) { } -static void set_curr_task_idle(struct rq *rq) -{ -} - /* * Simple, special scheduling class for the per-CPU idle tasks: */ @@ -70,7 +66,6 @@ static struct sched_class idle_sched_class __read_mostly = { .load_balance = load_balance_idle, - .set_curr_task = set_curr_task_idle, .task_tick = task_tick_idle, /* no .task_new for idle tasks */ }; diff --git a/kernel/sched_rt.c b/kernel/sched_rt.c index b86944c20f..3c77c03bdf 100644 --- a/kernel/sched_rt.c +++ b/kernel/sched_rt.c @@ -218,10 +218,6 @@ static void task_tick_rt(struct rq *rq, struct task_struct *p) } } -static void set_curr_task_rt(struct rq *rq) -{ -} - static struct sched_class rt_sched_class __read_mostly = { .enqueue_task = enqueue_task_rt, .dequeue_task = dequeue_task_rt, @@ -234,6 +230,5 @@ static struct sched_class rt_sched_class __read_mostly = { .load_balance = load_balance_rt, - .set_curr_task = set_curr_task_rt, .task_tick = task_tick_rt, }; -- 2.39.5