From d95f412200652694e63e64bfd49f0ae274a54479 Mon Sep 17 00:00:00 2001 From: Mike Galbraith Date: Tue, 1 Feb 2011 09:50:51 -0500 Subject: sched: Add yield_to(task, preempt) functionality Currently only implemented for fair class tasks. Add a yield_to_task method() to the fair scheduling class. allowing the caller of yield_to() to accelerate another thread in it's thread group, task group. Implemented via a scheduler hint, using cfs_rq->next to encourage the target being selected. We can rely on pick_next_entity to keep things fair, so noone can accelerate a thread that has already used its fair share of CPU time. This also means callers should only call yield_to when they really mean it. Calling it too often can result in the scheduler just ignoring the hint. Signed-off-by: Rik van Riel Signed-off-by: Marcelo Tosatti Signed-off-by: Mike Galbraith Signed-off-by: Peter Zijlstra LKML-Reference: <20110201095051.4ddb7738@annuminas.surriel.com> Signed-off-by: Ingo Molnar --- include/linux/sched.h | 2 ++ 1 file changed, 2 insertions(+) (limited to 'include/linux/sched.h') diff --git a/include/linux/sched.h b/include/linux/sched.h index 4e9fad271c30..c88b3bfbd09e 100644 --- a/include/linux/sched.h +++ b/include/linux/sched.h @@ -1058,6 +1058,7 @@ struct sched_class { void (*enqueue_task) (struct rq *rq, struct task_struct *p, int flags); void (*dequeue_task) (struct rq *rq, struct task_struct *p, int flags); void (*yield_task) (struct rq *rq); + bool (*yield_to_task) (struct rq *rq, struct task_struct *p, bool preempt); void (*check_preempt_curr) (struct rq *rq, struct task_struct *p, int flags); @@ -1972,6 +1973,7 @@ static inline int rt_mutex_getprio(struct task_struct *p) # define rt_mutex_adjust_pi(p) do { } while (0) #endif +extern bool yield_to(struct task_struct *p, bool preempt); extern void set_user_nice(struct task_struct *p, long nice); extern int task_prio(const struct task_struct *p); extern int task_nice(const struct task_struct *p); -- cgit v1.2.3