diff options
author | Vincent Guittot <vincent.guittot@linaro.org> | 2018-06-28 17:45:12 +0200 |
---|---|---|
committer | Ingo Molnar <mingo@kernel.org> | 2018-07-16 00:16:25 +0200 |
commit | 523e979d31648112bad07f427c183525c0258c75 (patch) | |
tree | 3ff54392a3016602e1d563d271ebe45f6aa778f2 | |
parent | dfa444dc2ff62edbaf1ff95ed22dd2ce8a5715da (diff) | |
download | linux-523e979d31648112bad07f427c183525c0258c75.tar.bz2 |
sched/core: Use PELT for scale_rt_capacity()
The utilization of the CPU by RT, DL and IRQs are now tracked with
PELT so we can use these metrics instead of rt_avg to evaluate the remaining
capacity available for CFS class.
scale_rt_capacity() behavior has been changed and now returns the remaining
capacity available for CFS instead of a scaling factor because RT, DL and
IRQ provide now absolute utilization value.
The same formula as schedutil is used:
IRQ util_avg + (1 - IRQ util_avg / max capacity ) * /Sum rq util_avg
but the implementation is different because it doesn't return the same value
and doesn't benefit of the same optimization.
Signed-off-by: Vincent Guittot <vincent.guittot@linaro.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Morten.Rasmussen@arm.com
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: claudio@evidence.eu.com
Cc: daniel.lezcano@linaro.org
Cc: dietmar.eggemann@arm.com
Cc: joel@joelfernandes.org
Cc: juri.lelli@redhat.com
Cc: luca.abeni@santannapisa.it
Cc: patrick.bellasi@arm.com
Cc: quentin.perret@arm.com
Cc: rjw@rjwysocki.net
Cc: valentin.schneider@arm.com
Cc: viresh.kumar@linaro.org
Link: http://lkml.kernel.org/r/1530200714-4504-10-git-send-email-vincent.guittot@linaro.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
-rw-r--r-- | kernel/sched/deadline.c | 2 | ||||
-rw-r--r-- | kernel/sched/fair.c | 44 | ||||
-rw-r--r-- | kernel/sched/pelt.c | 2 | ||||
-rw-r--r-- | kernel/sched/rt.c | 2 |
4 files changed, 23 insertions, 27 deletions
diff --git a/kernel/sched/deadline.c b/kernel/sched/deadline.c index f4de26982d80..68b8a9f1c9ca 100644 --- a/kernel/sched/deadline.c +++ b/kernel/sched/deadline.c @@ -1180,8 +1180,6 @@ static void update_curr_dl(struct rq *rq) curr->se.exec_start = now; cgroup_account_cputime(curr, delta_exec); - sched_rt_avg_update(rq, delta_exec); - if (dl_entity_is_special(dl_se)) return; diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c index c2782b29c79f..d265fa9756a2 100644 --- a/kernel/sched/fair.c +++ b/kernel/sched/fair.c @@ -7551,39 +7551,39 @@ static inline int get_sd_load_idx(struct sched_domain *sd, static unsigned long scale_rt_capacity(int cpu) { struct rq *rq = cpu_rq(cpu); - u64 total, used, age_stamp, avg; - s64 delta; - - /* - * Since we're reading these variables without serialization make sure - * we read them once before doing sanity checks on them. - */ - age_stamp = READ_ONCE(rq->age_stamp); - avg = READ_ONCE(rq->rt_avg); - delta = __rq_clock_broken(rq) - age_stamp; + unsigned long max = arch_scale_cpu_capacity(NULL, cpu); + unsigned long used, free; +#if defined(CONFIG_IRQ_TIME_ACCOUNTING) || defined(CONFIG_PARAVIRT_TIME_ACCOUNTING) + unsigned long irq; +#endif - if (unlikely(delta < 0)) - delta = 0; +#if defined(CONFIG_IRQ_TIME_ACCOUNTING) || defined(CONFIG_PARAVIRT_TIME_ACCOUNTING) + irq = READ_ONCE(rq->avg_irq.util_avg); - total = sched_avg_period() + delta; + if (unlikely(irq >= max)) + return 1; +#endif - used = div_u64(avg, total); + used = READ_ONCE(rq->avg_rt.util_avg); + used += READ_ONCE(rq->avg_dl.util_avg); - if (likely(used < SCHED_CAPACITY_SCALE)) - return SCHED_CAPACITY_SCALE - used; + if (unlikely(used >= max)) + return 1; - return 1; + free = max - used; +#if defined(CONFIG_IRQ_TIME_ACCOUNTING) || defined(CONFIG_PARAVIRT_TIME_ACCOUNTING) + free *= (max - irq); + free /= max; +#endif + return free; } static void update_cpu_capacity(struct sched_domain *sd, int cpu) { - unsigned long capacity = arch_scale_cpu_capacity(sd, cpu); + unsigned long capacity = scale_rt_capacity(cpu); struct sched_group *sdg = sd->groups; - cpu_rq(cpu)->cpu_capacity_orig = capacity; - - capacity *= scale_rt_capacity(cpu); - capacity >>= SCHED_CAPACITY_SHIFT; + cpu_rq(cpu)->cpu_capacity_orig = arch_scale_cpu_capacity(sd, cpu); if (!capacity) capacity = 1; diff --git a/kernel/sched/pelt.c b/kernel/sched/pelt.c index ead6d8b4a8b8..35475c0c5419 100644 --- a/kernel/sched/pelt.c +++ b/kernel/sched/pelt.c @@ -237,7 +237,7 @@ ___update_load_avg(struct sched_avg *sa, unsigned long load, unsigned long runna */ sa->load_avg = div_u64(load * sa->load_sum, divider); sa->runnable_load_avg = div_u64(runnable * sa->runnable_load_sum, divider); - sa->util_avg = sa->util_sum / divider; + WRITE_ONCE(sa->util_avg, sa->util_sum / divider); } /* diff --git a/kernel/sched/rt.c b/kernel/sched/rt.c index 0dc8ad1915e6..2df72abfa24a 100644 --- a/kernel/sched/rt.c +++ b/kernel/sched/rt.c @@ -973,8 +973,6 @@ static void update_curr_rt(struct rq *rq) curr->se.exec_start = now; cgroup_account_cputime(curr, delta_exec); - sched_rt_avg_update(rq, delta_exec); - if (!rt_bandwidth_enabled()) return; |