diff options
Diffstat (limited to 'kernel/sched/sched.h')
| -rw-r--r-- | kernel/sched/sched.h | 47 |
1 files changed, 45 insertions, 2 deletions
diff --git a/kernel/sched/sched.h b/kernel/sched/sched.h index 877fb08eb1b0..c82857e2e288 100644 --- a/kernel/sched/sched.h +++ b/kernel/sched/sched.h @@ -862,6 +862,8 @@ struct uclamp_rq { unsigned int value; struct uclamp_bucket bucket[UCLAMP_BUCKETS]; }; + +DECLARE_STATIC_KEY_FALSE(sched_uclamp_used); #endif /* CONFIG_UCLAMP_TASK */ /* @@ -2349,12 +2351,35 @@ static inline void cpufreq_update_util(struct rq *rq, unsigned int flags) {} #ifdef CONFIG_UCLAMP_TASK unsigned long uclamp_eff_value(struct task_struct *p, enum uclamp_id clamp_id); +/** + * uclamp_rq_util_with - clamp @util with @rq and @p effective uclamp values. + * @rq: The rq to clamp against. Must not be NULL. + * @util: The util value to clamp. + * @p: The task to clamp against. Can be NULL if you want to clamp + * against @rq only. + * + * Clamps the passed @util to the max(@rq, @p) effective uclamp values. + * + * If sched_uclamp_used static key is disabled, then just return the util + * without any clamping since uclamp aggregation at the rq level in the fast + * path is disabled, rendering this operation a NOP. + * + * Use uclamp_eff_value() if you don't care about uclamp values at rq level. It + * will return the correct effective uclamp value of the task even if the + * static key is disabled. + */ static __always_inline unsigned long uclamp_rq_util_with(struct rq *rq, unsigned long util, struct task_struct *p) { - unsigned long min_util = READ_ONCE(rq->uclamp[UCLAMP_MIN].value); - unsigned long max_util = READ_ONCE(rq->uclamp[UCLAMP_MAX].value); + unsigned long min_util; + unsigned long max_util; + + if (!static_branch_likely(&sched_uclamp_used)) + return util; + + min_util = READ_ONCE(rq->uclamp[UCLAMP_MIN].value); + max_util = READ_ONCE(rq->uclamp[UCLAMP_MAX].value); if (p) { min_util = max(min_util, uclamp_eff_value(p, UCLAMP_MIN)); @@ -2371,6 +2396,19 @@ unsigned long uclamp_rq_util_with(struct rq *rq, unsigned long util, return clamp(util, min_util, max_util); } + +/* + * When uclamp is compiled in, the aggregation at rq level is 'turned off' + * by default in the fast path and only gets turned on once userspace performs + * an operation that requires it. + * + * Returns true if userspace opted-in to use uclamp and aggregation at rq level + * hence is active. + */ +static inline bool uclamp_is_used(void) +{ + return static_branch_likely(&sched_uclamp_used); +} #else /* CONFIG_UCLAMP_TASK */ static inline unsigned long uclamp_rq_util_with(struct rq *rq, unsigned long util, @@ -2378,6 +2416,11 @@ unsigned long uclamp_rq_util_with(struct rq *rq, unsigned long util, { return util; } + +static inline bool uclamp_is_used(void) +{ + return false; +} #endif /* CONFIG_UCLAMP_TASK */ #ifdef arch_scale_freq_capacity |