diff options
author | 2015-02-04 07:44:00 +0100 | |
---|---|---|
committer | 2015-02-04 07:44:00 +0100 | |
commit | 4c195c8a1967ff8bee13a811518a99db04618ab7 (patch) | |
tree | 555682bd243ac56920ef7a2f3c1f3b666996c7b3 /kernel/sched | |
parent | sched/deadline: Modify cpudl::free_cpus to reflect rd->online (diff) | |
parent | sched/deadline: Fix deadline parameter modification handling (diff) | |
download | linux-4c195c8a1967ff8bee13a811518a99db04618ab7.tar.gz linux-4c195c8a1967ff8bee13a811518a99db04618ab7.tar.bz2 linux-4c195c8a1967ff8bee13a811518a99db04618ab7.zip |
Merge branch 'sched/urgent' into sched/core, to merge fixes before applying new patches
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'kernel/sched')
-rw-r--r-- | kernel/sched/core.c | 33 | ||||
-rw-r--r-- | kernel/sched/deadline.c | 3 |
2 files changed, 30 insertions, 6 deletions
diff --git a/kernel/sched/core.c b/kernel/sched/core.c index 54dce019c0ce..50a5352f6205 100644 --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -1816,6 +1816,10 @@ void __dl_clear_params(struct task_struct *p) dl_se->dl_period = 0; dl_se->flags = 0; dl_se->dl_bw = 0; + + dl_se->dl_throttled = 0; + dl_se->dl_new = 1; + dl_se->dl_yielded = 0; } /* @@ -1844,7 +1848,7 @@ static void __sched_fork(unsigned long clone_flags, struct task_struct *p) #endif RB_CLEAR_NODE(&p->dl.rb_node); - hrtimer_init(&p->dl.dl_timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL); + init_dl_task_timer(&p->dl); __dl_clear_params(p); INIT_LIST_HEAD(&p->rt.run_list); @@ -2054,6 +2058,9 @@ static inline int dl_bw_cpus(int i) * allocated bandwidth to reflect the new situation. * * This function is called while holding p's rq->lock. + * + * XXX we should delay bw change until the task's 0-lag point, see + * __setparam_dl(). */ static int dl_overflow(struct task_struct *p, int policy, const struct sched_attr *attr) @@ -3263,15 +3270,31 @@ __setparam_dl(struct task_struct *p, const struct sched_attr *attr) { struct sched_dl_entity *dl_se = &p->dl; - init_dl_task_timer(dl_se); dl_se->dl_runtime = attr->sched_runtime; dl_se->dl_deadline = attr->sched_deadline; dl_se->dl_period = attr->sched_period ?: dl_se->dl_deadline; dl_se->flags = attr->sched_flags; dl_se->dl_bw = to_ratio(dl_se->dl_period, dl_se->dl_runtime); - dl_se->dl_throttled = 0; - dl_se->dl_new = 1; - dl_se->dl_yielded = 0; + + /* + * Changing the parameters of a task is 'tricky' and we're not doing + * the correct thing -- also see task_dead_dl() and switched_from_dl(). + * + * What we SHOULD do is delay the bandwidth release until the 0-lag + * point. This would include retaining the task_struct until that time + * and change dl_overflow() to not immediately decrement the current + * amount. + * + * Instead we retain the current runtime/deadline and let the new + * parameters take effect after the current reservation period lapses. + * This is safe (albeit pessimistic) because the 0-lag point is always + * before the current scheduling deadline. + * + * We can still have temporary overloads because we do not delay the + * change in bandwidth until that time; so admission control is + * not on the safe side. It does however guarantee tasks will never + * consume more than promised. + */ } /* diff --git a/kernel/sched/deadline.c b/kernel/sched/deadline.c index e7b272233c5c..e0e9c2986976 100644 --- a/kernel/sched/deadline.c +++ b/kernel/sched/deadline.c @@ -1094,6 +1094,7 @@ static void task_dead_dl(struct task_struct *p) * Since we are TASK_DEAD we won't slip out of the domain! */ raw_spin_lock_irq(&dl_b->lock); + /* XXX we should retain the bw until 0-lag */ dl_b->total_bw -= p->dl.dl_bw; raw_spin_unlock_irq(&dl_b->lock); @@ -1613,8 +1614,8 @@ static void cancel_dl_timer(struct rq *rq, struct task_struct *p) static void switched_from_dl(struct rq *rq, struct task_struct *p) { + /* XXX we should retain the bw until 0-lag */ cancel_dl_timer(rq, p); - __dl_clear_params(p); /* |