linux/kernel/sched/pelt.h
Vincent Guittot 11137d3849 sched/fair: Simplify util_est
With UTIL_EST_FASTUP now being permanent, we can take advantage of the
fact that the ewma jumps directly to a higher utilization at dequeue to
simplify util_est and remove the enqueued field.

Signed-off-by: Vincent Guittot <vincent.guittot@linaro.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Tested-by: Lukasz Luba <lukasz.luba@arm.com>
Reviewed-by: Lukasz Luba <lukasz.luba@arm.com>
Reviewed-by: Dietmar Eggemann <dietmar.eggemann@arm.com>
Reviewed-by: Hongyan Xia <hongyan.xia2@arm.com>
Reviewed-by: Alex Shi <alexs@kernel.org>
Link: https://lore.kernel.org/r/20231201161652.1241695-3-vincent.guittot@linaro.org
2023-12-23 15:59:58 +01:00

236 lines
6.0 KiB
C

#ifdef CONFIG_SMP
#include "sched-pelt.h"
int __update_load_avg_blocked_se(u64 now, struct sched_entity *se);
int __update_load_avg_se(u64 now, struct cfs_rq *cfs_rq, struct sched_entity *se);
int __update_load_avg_cfs_rq(u64 now, struct cfs_rq *cfs_rq);
int update_rt_rq_load_avg(u64 now, struct rq *rq, int running);
int update_dl_rq_load_avg(u64 now, struct rq *rq, int running);
#ifdef CONFIG_SCHED_THERMAL_PRESSURE
int update_thermal_load_avg(u64 now, struct rq *rq, u64 capacity);
static inline u64 thermal_load_avg(struct rq *rq)
{
return READ_ONCE(rq->avg_thermal.load_avg);
}
#else
static inline int
update_thermal_load_avg(u64 now, struct rq *rq, u64 capacity)
{
return 0;
}
static inline u64 thermal_load_avg(struct rq *rq)
{
return 0;
}
#endif
#ifdef CONFIG_HAVE_SCHED_AVG_IRQ
int update_irq_load_avg(struct rq *rq, u64 running);
#else
static inline int
update_irq_load_avg(struct rq *rq, u64 running)
{
return 0;
}
#endif
#define PELT_MIN_DIVIDER (LOAD_AVG_MAX - 1024)
static inline u32 get_pelt_divider(struct sched_avg *avg)
{
return PELT_MIN_DIVIDER + avg->period_contrib;
}
static inline void cfs_se_util_change(struct sched_avg *avg)
{
unsigned int enqueued;
if (!sched_feat(UTIL_EST))
return;
/* Avoid store if the flag has been already reset */
enqueued = avg->util_est;
if (!(enqueued & UTIL_AVG_UNCHANGED))
return;
/* Reset flag to report util_avg has been updated */
enqueued &= ~UTIL_AVG_UNCHANGED;
WRITE_ONCE(avg->util_est, enqueued);
}
static inline u64 rq_clock_pelt(struct rq *rq)
{
lockdep_assert_rq_held(rq);
assert_clock_updated(rq);
return rq->clock_pelt - rq->lost_idle_time;
}
/* The rq is idle, we can sync to clock_task */
static inline void _update_idle_rq_clock_pelt(struct rq *rq)
{
rq->clock_pelt = rq_clock_task(rq);
u64_u32_store(rq->clock_idle, rq_clock(rq));
/* Paired with smp_rmb in migrate_se_pelt_lag() */
smp_wmb();
u64_u32_store(rq->clock_pelt_idle, rq_clock_pelt(rq));
}
/*
* The clock_pelt scales the time to reflect the effective amount of
* computation done during the running delta time but then sync back to
* clock_task when rq is idle.
*
*
* absolute time | 1| 2| 3| 4| 5| 6| 7| 8| 9|10|11|12|13|14|15|16
* @ max capacity ------******---------------******---------------
* @ half capacity ------************---------************---------
* clock pelt | 1| 2| 3| 4| 7| 8| 9| 10| 11|14|15|16
*
*/
static inline void update_rq_clock_pelt(struct rq *rq, s64 delta)
{
if (unlikely(is_idle_task(rq->curr))) {
_update_idle_rq_clock_pelt(rq);
return;
}
/*
* When a rq runs at a lower compute capacity, it will need
* more time to do the same amount of work than at max
* capacity. In order to be invariant, we scale the delta to
* reflect how much work has been really done.
* Running longer results in stealing idle time that will
* disturb the load signal compared to max capacity. This
* stolen idle time will be automatically reflected when the
* rq will be idle and the clock will be synced with
* rq_clock_task.
*/
/*
* Scale the elapsed time to reflect the real amount of
* computation
*/
delta = cap_scale(delta, arch_scale_cpu_capacity(cpu_of(rq)));
delta = cap_scale(delta, arch_scale_freq_capacity(cpu_of(rq)));
rq->clock_pelt += delta;
}
/*
* When rq becomes idle, we have to check if it has lost idle time
* because it was fully busy. A rq is fully used when the /Sum util_sum
* is greater or equal to:
* (LOAD_AVG_MAX - 1024 + rq->cfs.avg.period_contrib) << SCHED_CAPACITY_SHIFT;
* For optimization and computing rounding purpose, we don't take into account
* the position in the current window (period_contrib) and we use the higher
* bound of util_sum to decide.
*/
static inline void update_idle_rq_clock_pelt(struct rq *rq)
{
u32 divider = ((LOAD_AVG_MAX - 1024) << SCHED_CAPACITY_SHIFT) - LOAD_AVG_MAX;
u32 util_sum = rq->cfs.avg.util_sum;
util_sum += rq->avg_rt.util_sum;
util_sum += rq->avg_dl.util_sum;
/*
* Reflecting stolen time makes sense only if the idle
* phase would be present at max capacity. As soon as the
* utilization of a rq has reached the maximum value, it is
* considered as an always running rq without idle time to
* steal. This potential idle time is considered as lost in
* this case. We keep track of this lost idle time compare to
* rq's clock_task.
*/
if (util_sum >= divider)
rq->lost_idle_time += rq_clock_task(rq) - rq->clock_pelt;
_update_idle_rq_clock_pelt(rq);
}
#ifdef CONFIG_CFS_BANDWIDTH
static inline void update_idle_cfs_rq_clock_pelt(struct cfs_rq *cfs_rq)
{
u64 throttled;
if (unlikely(cfs_rq->throttle_count))
throttled = U64_MAX;
else
throttled = cfs_rq->throttled_clock_pelt_time;
u64_u32_store(cfs_rq->throttled_pelt_idle, throttled);
}
/* rq->task_clock normalized against any time this cfs_rq has spent throttled */
static inline u64 cfs_rq_clock_pelt(struct cfs_rq *cfs_rq)
{
if (unlikely(cfs_rq->throttle_count))
return cfs_rq->throttled_clock_pelt - cfs_rq->throttled_clock_pelt_time;
return rq_clock_pelt(rq_of(cfs_rq)) - cfs_rq->throttled_clock_pelt_time;
}
#else
static inline void update_idle_cfs_rq_clock_pelt(struct cfs_rq *cfs_rq) { }
static inline u64 cfs_rq_clock_pelt(struct cfs_rq *cfs_rq)
{
return rq_clock_pelt(rq_of(cfs_rq));
}
#endif
#else
static inline int
update_cfs_rq_load_avg(u64 now, struct cfs_rq *cfs_rq)
{
return 0;
}
static inline int
update_rt_rq_load_avg(u64 now, struct rq *rq, int running)
{
return 0;
}
static inline int
update_dl_rq_load_avg(u64 now, struct rq *rq, int running)
{
return 0;
}
static inline int
update_thermal_load_avg(u64 now, struct rq *rq, u64 capacity)
{
return 0;
}
static inline u64 thermal_load_avg(struct rq *rq)
{
return 0;
}
static inline int
update_irq_load_avg(struct rq *rq, u64 running)
{
return 0;
}
static inline u64 rq_clock_pelt(struct rq *rq)
{
return rq_clock_task(rq);
}
static inline void
update_rq_clock_pelt(struct rq *rq, s64 delta) { }
static inline void
update_idle_rq_clock_pelt(struct rq *rq) { }
static inline void update_idle_cfs_rq_clock_pelt(struct cfs_rq *cfs_rq) { }
#endif