From 83b699ed20f5218580a1b7042064082e2e05f8c5 Mon Sep 17 00:00:00 2001 From: Srivatsa Vaddagiri Date: Mon, 15 Oct 2007 17:00:08 +0200 Subject: [PATCH] sched: revert recent removal of set_curr_task() Revert removal of set_curr_task. Use put_prev_task/set_curr_task when changing groups/policies Signed-off-by: Srivatsa Vaddagiri < vatsa@linux.vnet.ibm.com> Signed-off-by: Dhaval Giani Signed-off-by: Ingo Molnar Signed-off-by: Peter Zijlstra --- include/linux/sched.h | 1 + kernel/sched.c | 34 ++++++++++++++++----- kernel/sched_fair.c | 68 +++++++++++++++++++---------------------- kernel/sched_idletask.c | 5 +++ kernel/sched_rt.c | 8 +++++ 5 files changed, 72 insertions(+), 44 deletions(-) diff --git a/include/linux/sched.h b/include/linux/sched.h index abcb02738d95..66169005f008 100644 --- a/include/linux/sched.h +++ b/include/linux/sched.h @@ -871,6 +871,7 @@ 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 72c936d3e332..ee7ac71b12f8 100644 --- a/kernel/sched.c +++ b/kernel/sched.c @@ -3916,7 +3916,7 @@ EXPORT_SYMBOL(sleep_on_timeout); void rt_mutex_setprio(struct task_struct *p, int prio) { unsigned long flags; - int oldprio, on_rq; + int oldprio, on_rq, running; struct rq *rq; BUG_ON(prio < 0 || prio > MAX_PRIO); @@ -3926,8 +3926,12 @@ void rt_mutex_setprio(struct task_struct *p, int prio) oldprio = p->prio; on_rq = p->se.on_rq; - if (on_rq) + running = task_running(rq, p); + 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; @@ -3937,13 +3941,15 @@ 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 (task_running(rq, p)) { + if (running) { if (p->prio > oldprio) resched_task(rq->curr); } else { @@ -4149,7 +4155,7 @@ __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; + int retval, oldprio, oldpolicy = -1, on_rq, running; unsigned long flags; struct rq *rq; @@ -4231,20 +4237,26 @@ int sched_setscheduler(struct task_struct *p, int policy, } update_rq_clock(rq); on_rq = p->se.on_rq; - if (on_rq) + running = task_running(rq, p); + 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 (task_running(rq, p)) { + if (running) { if (p->prio > oldprio) resched_task(rq->curr); } else { @@ -6845,13 +6857,19 @@ 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 (on_rq) { + if (unlikely(running)) + tsk->sched_class->set_curr_task(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 9f93a5c127e8..92563cd5af75 100644 --- a/kernel/sched_fair.c +++ b/kernel/sched_fair.c @@ -472,19 +472,8 @@ 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, int set_curr) +enqueue_entity(struct cfs_rq *cfs_rq, struct sched_entity *se, int wakeup) { - /* - * 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. */ @@ -496,7 +485,8 @@ enqueue_entity(struct cfs_rq *cfs_rq, struct sched_entity *se, } 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); } @@ -516,12 +506,8 @@ dequeue_entity(struct cfs_rq *cfs_rq, struct sched_entity *se, int sleep) } } #endif - if (likely(se != cfs_rq->curr)) + if (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); } @@ -539,15 +525,20 @@ check_preempt_tick(struct cfs_rq *cfs_rq, struct sched_entity *curr) resched_task(rq_of(cfs_rq)->curr); } -static inline void +static void set_next_entity(struct cfs_rq *cfs_rq, struct sched_entity *se) { - /* - * Any task has to be enqueued before it get to execute on - * a CPU. So account for the time it spent waiting on the - * runqueue. - */ - update_stats_wait_end(cfs_rq, se); + /* 'current' is not kept within the tree. */ + if (se->on_rq) { + /* + * Any task has to be enqueued before it get to execute on + * a CPU. So account for the time it spent waiting on the + * runqueue. + */ + update_stats_wait_end(cfs_rq, se); + __dequeue_entity(cfs_rq, se); + } + update_stats_curr_start(cfs_rq, se); cfs_rq->curr = se; #ifdef CONFIG_SCHEDSTATS @@ -568,10 +559,6 @@ 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; @@ -703,17 +690,12 @@ 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, set_curr); + enqueue_entity(cfs_rq, se, wakeup); } } @@ -761,7 +743,7 @@ static void yield_task_fair(struct rq *rq) * position within the tree: */ dequeue_entity(cfs_rq, se, 0); - enqueue_entity(cfs_rq, se, 0, 1); + enqueue_entity(cfs_rq, se, 0); return; } @@ -1004,6 +986,19 @@ static void task_new_fair(struct rq *rq, struct task_struct *p) resched_task(rq->curr); } +/* 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); +} + /* * All the scheduling class methods: */ @@ -1019,6 +1014,7 @@ 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 3503fb2d9f96..5ebf829cdd73 100644 --- a/kernel/sched_idletask.c +++ b/kernel/sched_idletask.c @@ -50,6 +50,10 @@ 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: */ @@ -66,6 +70,7 @@ 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 3c77c03bdf1e..e1d5f1c8b532 100644 --- a/kernel/sched_rt.c +++ b/kernel/sched_rt.c @@ -218,6 +218,13 @@ static void task_tick_rt(struct rq *rq, struct task_struct *p) } } +static void set_curr_task_rt(struct rq *rq) +{ + struct task_struct *p = rq->curr; + + p->se.exec_start = rq->clock; +} + static struct sched_class rt_sched_class __read_mostly = { .enqueue_task = enqueue_task_rt, .dequeue_task = dequeue_task_rt, @@ -230,5 +237,6 @@ 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, }; -- GitLab