From ea87bb7853168434f4a82426dd1ea8421f9e604d Mon Sep 17 00:00:00 2001 From: Thomas Gleixner Date: Wed, 20 Jan 2010 20:58:57 +0000 Subject: [PATCH] sched: Extend enqueue_task to allow head queueing The ability of enqueueing a task to the head of a SCHED_FIFO priority list is required to fix some violations of POSIX scheduling policy. Extend the related functions with a "head" argument. Signed-off-by: Thomas Gleixner Acked-by: Peter Zijlstra Tested-by: Carsten Emde Tested-by: Mathias Weber LKML-Reference: <20100120171629.734886007@linutronix.de> --- include/linux/sched.h | 3 ++- kernel/sched.c | 13 +++++++------ kernel/sched_fair.c | 3 ++- kernel/sched_rt.c | 3 ++- 4 files changed, 13 insertions(+), 9 deletions(-) diff --git a/include/linux/sched.h b/include/linux/sched.h index 8b079735ae5f..b35c0c7130c8 100644 --- a/include/linux/sched.h +++ b/include/linux/sched.h @@ -1067,7 +1067,8 @@ struct sched_domain; struct sched_class { const struct sched_class *next; - void (*enqueue_task) (struct rq *rq, struct task_struct *p, int wakeup); + void (*enqueue_task) (struct rq *rq, struct task_struct *p, int wakeup, + bool head); void (*dequeue_task) (struct rq *rq, struct task_struct *p, int sleep); void (*yield_task) (struct rq *rq); diff --git a/kernel/sched.c b/kernel/sched.c index 41e76d325648..f47560ff3346 100644 --- a/kernel/sched.c +++ b/kernel/sched.c @@ -1856,13 +1856,14 @@ static void update_avg(u64 *avg, u64 sample) *avg += diff >> 3; } -static void enqueue_task(struct rq *rq, struct task_struct *p, int wakeup) +static void +enqueue_task(struct rq *rq, struct task_struct *p, int wakeup, bool head) { if (wakeup) p->se.start_runtime = p->se.sum_exec_runtime; sched_info_queued(p); - p->sched_class->enqueue_task(rq, p, wakeup); + p->sched_class->enqueue_task(rq, p, wakeup, head); p->se.on_rq = 1; } @@ -1892,7 +1893,7 @@ static void activate_task(struct rq *rq, struct task_struct *p, int wakeup) if (task_contributes_to_load(p)) rq->nr_uninterruptible--; - enqueue_task(rq, p, wakeup); + enqueue_task(rq, p, wakeup, false); inc_nr_running(rq); } @@ -4236,7 +4237,7 @@ void rt_mutex_setprio(struct task_struct *p, int prio) if (running) p->sched_class->set_curr_task(rq); if (on_rq) { - enqueue_task(rq, p, 0); + enqueue_task(rq, p, 0, false); check_class_changed(rq, p, prev_class, oldprio, running); } @@ -4280,7 +4281,7 @@ void set_user_nice(struct task_struct *p, long nice) delta = p->prio - old_prio; if (on_rq) { - enqueue_task(rq, p, 0); + enqueue_task(rq, p, 0, false); /* * If the task increased its priority or is running and * lowered its priority, then reschedule its CPU: @@ -8230,7 +8231,7 @@ void sched_move_task(struct task_struct *tsk) if (unlikely(running)) tsk->sched_class->set_curr_task(rq); if (on_rq) - enqueue_task(rq, tsk, 0); + enqueue_task(rq, tsk, 0, false); task_rq_unlock(rq, &flags); } diff --git a/kernel/sched_fair.c b/kernel/sched_fair.c index 22231ccb2f98..0e7a7af9cf8b 100644 --- a/kernel/sched_fair.c +++ b/kernel/sched_fair.c @@ -1053,7 +1053,8 @@ static inline void hrtick_update(struct rq *rq) * increased. Here we update the fair scheduling stats and * then put the task into the rbtree: */ -static void enqueue_task_fair(struct rq *rq, struct task_struct *p, int wakeup) +static void +enqueue_task_fair(struct rq *rq, struct task_struct *p, int wakeup, bool head) { struct cfs_rq *cfs_rq; struct sched_entity *se = &p->se; diff --git a/kernel/sched_rt.c b/kernel/sched_rt.c index 502bb614e40a..38076dabb44a 100644 --- a/kernel/sched_rt.c +++ b/kernel/sched_rt.c @@ -878,7 +878,8 @@ static void dequeue_rt_entity(struct sched_rt_entity *rt_se) /* * Adding/removing a task to/from a priority array: */ -static void enqueue_task_rt(struct rq *rq, struct task_struct *p, int wakeup) +static void +enqueue_task_rt(struct rq *rq, struct task_struct *p, int wakeup, bool head) { struct sched_rt_entity *rt_se = &p->rt;