Messages in this thread Patch in this message | | | Subject | [RFC][PATCH 09/22] sched: add period support for -deadline tasks | From | Raistlin <> | Date | Fri, 29 Oct 2010 08:34:10 +0200 |
| |
Make it possible to specify a period (different or equal than deadline) for -deadline tasks.
Signed-off-by: Harald Gustafsson <harald.gustafsson@ericsson.com> Signed-off-by: Dario Faggioli <raistlin@linux.it> --- include/linux/sched.h | 1 + kernel/sched.c | 12 +++++++++++- kernel/sched_dl.c | 8 ++++++-- 3 files changed, 18 insertions(+), 3 deletions(-)
diff --git a/include/linux/sched.h b/include/linux/sched.h index f25d3a6..83fa2b5 100644 --- a/include/linux/sched.h +++ b/include/linux/sched.h @@ -1251,6 +1251,7 @@ struct sched_dl_entity { */ u64 dl_runtime; /* maximum runtime for each instance */ u64 dl_deadline; /* relative deadline of each instance */ + u64 dl_period; /* separation of two instances (period) */ /* * Actual scheduling parameters. Initialized with the values above, diff --git a/kernel/sched.c b/kernel/sched.c index 7f0780c..4491f7d 100644 --- a/kernel/sched.c +++ b/kernel/sched.c @@ -2708,6 +2708,7 @@ static void __sched_fork(struct task_struct *p) hrtimer_init(&p->dl.dl_timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL); p->dl.dl_runtime = p->dl.runtime = 0; p->dl.dl_deadline = p->dl.deadline = 0; + p->dl.dl_period = 0; p->dl.flags = 0; INIT_LIST_HEAD(&p->rt.run_list); @@ -4789,6 +4790,10 @@ __setparam_dl(struct task_struct *p, const struct sched_param_ex *param_ex) init_dl_task_timer(dl_se); dl_se->dl_runtime = timespec_to_ns(¶m_ex->sched_runtime); dl_se->dl_deadline = timespec_to_ns(¶m_ex->sched_deadline); + if (timespec_to_ns(¶m_ex->sched_period) != 0) + dl_se->dl_period = timespec_to_ns(¶m_ex->sched_period); + else + dl_se->dl_period = dl_se->dl_deadline; dl_se->flags = param_ex->sched_flags; dl_se->dl_throttled = 0; dl_se->dl_new = 1; @@ -4802,6 +4807,7 @@ __getparam_dl(struct task_struct *p, struct sched_param_ex *param_ex) param_ex->sched_priority = p->rt_priority; param_ex->sched_runtime = ns_to_timespec(dl_se->dl_runtime); param_ex->sched_deadline = ns_to_timespec(dl_se->dl_deadline); + param_ex->sched_period = ns_to_timespec(dl_se->dl_period); param_ex->sched_flags = dl_se->flags; param_ex->curr_runtime = ns_to_timespec(dl_se->runtime); param_ex->curr_deadline = ns_to_timespec(dl_se->deadline); @@ -4810,7 +4816,8 @@ __getparam_dl(struct task_struct *p, struct sched_param_ex *param_ex) /* * This function validates the new parameters of a -deadline task. * We ask for the deadline not being zero, and greater or equal - * than the runtime. + * than the runtime, as well as the period of being zero or + * not greater than deadline. */ static bool __checkparam_dl(const struct sched_param_ex *prm, bool kthread) @@ -4822,6 +4829,9 @@ __checkparam_dl(const struct sched_param_ex *prm, bool kthread) return kthread; return timespec_to_ns(&prm->sched_deadline) != 0 && + (timespec_to_ns(&prm->sched_period) == 0 || + timespec_compare(&prm->sched_period, + &prm->sched_deadline) >= 0) && timespec_compare(&prm->sched_deadline, &prm->sched_runtime) >= 0; } diff --git a/kernel/sched_dl.c b/kernel/sched_dl.c index 1bb4308..31fb771 100644 --- a/kernel/sched_dl.c +++ b/kernel/sched_dl.c @@ -263,7 +263,7 @@ static void replenish_dl_entity(struct sched_dl_entity *dl_se) * arbitrary large. */ while (dl_se->runtime <= 0) { - dl_se->deadline += dl_se->dl_deadline; + dl_se->deadline += dl_se->dl_period; dl_se->runtime += dl_se->dl_runtime; } @@ -290,7 +290,11 @@ static void replenish_dl_entity(struct sched_dl_entity *dl_se) * assigned (function returns true if it can). * * For this to hold, we must check if: - * runtime / (deadline - t) < dl_runtime / dl_deadline . + * runtime / (deadline - t) < dl_runtime / dl_period . + * + * Notice that the bandwidth check is done against the period. For + * task with deadline equal to period this is the same of using + * dl_deadline instead of dl_period in the equation above. */ static bool dl_entity_overflow(struct sched_dl_entity *dl_se, u64 t) { -- 1.7.2.3
-- <<This happens because I choose it to happen!>> (Raistlin Majere) ---------------------------------------------------------------------- Dario Faggioli, ReTiS Lab, Scuola Superiore Sant'Anna, Pisa (Italy) http://blog.linux.it/raistlin / raistlin@ekiga.net / dario.faggioli@jabber.org [unhandled content-type:application/pgp-signature]
| |