From ede3d0fba99520f268067917b50858d788bc41da Mon Sep 17 00:00:00 2001 From: Con Kolivas Date: Tue, 8 Nov 2005 21:39:00 -0800 Subject: [PATCH] [PATCH] sched: consider migration thread with smp nice The intermittent scheduling of the migration thread at ultra high priority makes the smp nice handling see that runqueue as being heavily loaded. The migration thread itself actually handles the balancing so its influence on priority balancing should be ignored. Signed-off-by: Con Kolivas Cc: Ingo Molnar Cc: Nick Piggin Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- kernel/sched.c | 35 ++++++++++++++++++++++++++--------- 1 file changed, 26 insertions(+), 9 deletions(-) diff --git a/kernel/sched.c b/kernel/sched.c index 502d47c883b6..0f2def822296 100644 --- a/kernel/sched.c +++ b/kernel/sched.c @@ -670,6 +670,31 @@ static inline void dec_prio_bias(runqueue_t *rq, int prio) { rq->prio_bias -= MAX_PRIO - prio; } + +static inline void inc_nr_running(task_t *p, runqueue_t *rq) +{ + rq->nr_running++; + if (rt_task(p)) { + if (p != rq->migration_thread) + /* + * The migration thread does the actual balancing. Do + * not bias by its priority as the ultra high priority + * will skew balancing adversely. + */ + inc_prio_bias(rq, p->prio); + } else + inc_prio_bias(rq, p->static_prio); +} + +static inline void dec_nr_running(task_t *p, runqueue_t *rq) +{ + rq->nr_running--; + if (rt_task(p)) { + if (p != rq->migration_thread) + dec_prio_bias(rq, p->prio); + } else + dec_prio_bias(rq, p->static_prio); +} #else static inline void inc_prio_bias(runqueue_t *rq, int prio) { @@ -678,25 +703,17 @@ static inline void inc_prio_bias(runqueue_t *rq, int prio) static inline void dec_prio_bias(runqueue_t *rq, int prio) { } -#endif static inline void inc_nr_running(task_t *p, runqueue_t *rq) { rq->nr_running++; - if (rt_task(p)) - inc_prio_bias(rq, p->prio); - else - inc_prio_bias(rq, p->static_prio); } static inline void dec_nr_running(task_t *p, runqueue_t *rq) { rq->nr_running--; - if (rt_task(p)) - dec_prio_bias(rq, p->prio); - else - dec_prio_bias(rq, p->static_prio); } +#endif /* * __activate_task - move a task to the runqueue. -- 2.20.1