From f12560779f9d734446508f3df17f5632e9aaa2c8 Mon Sep 17 00:00:00 2001 From: Vincent Guittot Date: Wed, 22 Nov 2023 14:39:04 +0100 Subject: sched/cpufreq: Rework iowait boost Use the max value that has already been computed inside sugov_get_util() to cap the iowait boost and remove dependency with uclamp_rq_util_with() which is not used anymore. Signed-off-by: Vincent Guittot Signed-off-by: Ingo Molnar Acked-by: Rafael J. Wysocki Link: https://lore.kernel.org/r/20231122133904.446032-3-vincent.guittot@linaro.org --- kernel/sched/cpufreq_schedutil.c | 29 ++++++++++--------- kernel/sched/sched.h | 60 ---------------------------------------- 2 files changed, 14 insertions(+), 75 deletions(-) diff --git a/kernel/sched/cpufreq_schedutil.c b/kernel/sched/cpufreq_schedutil.c index f3acf2cf26ed..4ee8ad70be99 100644 --- a/kernel/sched/cpufreq_schedutil.c +++ b/kernel/sched/cpufreq_schedutil.c @@ -169,11 +169,12 @@ unsigned long sugov_effective_cpu_perf(int cpu, unsigned long actual, return max(min, max); } -static void sugov_get_util(struct sugov_cpu *sg_cpu) +static void sugov_get_util(struct sugov_cpu *sg_cpu, unsigned long boost) { unsigned long min, max, util = cpu_util_cfs_boost(sg_cpu->cpu); util = effective_cpu_util(sg_cpu->cpu, util, &min, &max); + util = max(util, boost); sg_cpu->bw_min = min; sg_cpu->util = sugov_effective_cpu_perf(sg_cpu->cpu, util, min, max); } @@ -266,18 +267,16 @@ static void sugov_iowait_boost(struct sugov_cpu *sg_cpu, u64 time, * This mechanism is designed to boost high frequently IO waiting tasks, while * being more conservative on tasks which does sporadic IO operations. */ -static void sugov_iowait_apply(struct sugov_cpu *sg_cpu, u64 time, +static unsigned long sugov_iowait_apply(struct sugov_cpu *sg_cpu, u64 time, unsigned long max_cap) { - unsigned long boost; - /* No boost currently required */ if (!sg_cpu->iowait_boost) - return; + return 0; /* Reset boost if the CPU appears to have been idle enough */ if (sugov_iowait_reset(sg_cpu, time, false)) - return; + return 0; if (!sg_cpu->iowait_boost_pending) { /* @@ -286,7 +285,7 @@ static void sugov_iowait_apply(struct sugov_cpu *sg_cpu, u64 time, sg_cpu->iowait_boost >>= 1; if (sg_cpu->iowait_boost < IOWAIT_BOOST_MIN) { sg_cpu->iowait_boost = 0; - return; + return 0; } } @@ -296,10 +295,7 @@ static void sugov_iowait_apply(struct sugov_cpu *sg_cpu, u64 time, * sg_cpu->util is already in capacity scale; convert iowait_boost * into the same scale so we can compare. */ - boost = (sg_cpu->iowait_boost * max_cap) >> SCHED_CAPACITY_SHIFT; - boost = uclamp_rq_util_with(cpu_rq(sg_cpu->cpu), boost, NULL); - if (sg_cpu->util < boost) - sg_cpu->util = boost; + return (sg_cpu->iowait_boost * max_cap) >> SCHED_CAPACITY_SHIFT; } #ifdef CONFIG_NO_HZ_COMMON @@ -329,6 +325,8 @@ static inline bool sugov_update_single_common(struct sugov_cpu *sg_cpu, u64 time, unsigned long max_cap, unsigned int flags) { + unsigned long boost; + sugov_iowait_boost(sg_cpu, time, flags); sg_cpu->last_update = time; @@ -337,8 +335,8 @@ static inline bool sugov_update_single_common(struct sugov_cpu *sg_cpu, if (!sugov_should_update_freq(sg_cpu->sg_policy, time)) return false; - sugov_get_util(sg_cpu); - sugov_iowait_apply(sg_cpu, time, max_cap); + boost = sugov_iowait_apply(sg_cpu, time, max_cap); + sugov_get_util(sg_cpu, boost); return true; } @@ -439,9 +437,10 @@ static unsigned int sugov_next_freq_shared(struct sugov_cpu *sg_cpu, u64 time) for_each_cpu(j, policy->cpus) { struct sugov_cpu *j_sg_cpu = &per_cpu(sugov_cpu, j); + unsigned long boost; - sugov_get_util(j_sg_cpu); - sugov_iowait_apply(j_sg_cpu, time, max_cap); + boost = sugov_iowait_apply(j_sg_cpu, time, max_cap); + sugov_get_util(j_sg_cpu, boost); util = max(j_sg_cpu->util, util); } diff --git a/kernel/sched/sched.h b/kernel/sched/sched.h index c1574cd388e7..e58a54bda77d 100644 --- a/kernel/sched/sched.h +++ b/kernel/sched/sched.h @@ -3058,59 +3058,6 @@ static inline bool uclamp_rq_is_idle(struct rq *rq) return rq->uclamp_flags & UCLAMP_FLAG_IDLE; } -/** - * 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 = 0; - unsigned long max_util = 0; - - if (!static_branch_likely(&sched_uclamp_used)) - return util; - - if (p) { - min_util = uclamp_eff_value(p, UCLAMP_MIN); - max_util = uclamp_eff_value(p, UCLAMP_MAX); - - /* - * Ignore last runnable task's max clamp, as this task will - * reset it. Similarly, no need to read the rq's min clamp. - */ - if (uclamp_rq_is_idle(rq)) - goto out; - } - - min_util = max_t(unsigned long, min_util, uclamp_rq_get(rq, UCLAMP_MIN)); - max_util = max_t(unsigned long, max_util, uclamp_rq_get(rq, UCLAMP_MAX)); -out: - /* - * Since CPU's {min,max}_util clamps are MAX aggregated considering - * RUNNABLE tasks with _different_ clamps, we can end up with an - * inversion. Fix it now when the clamps are applied. - */ - if (unlikely(min_util >= max_util)) - return min_util; - - return clamp(util, min_util, max_util); -} - /* Is the rq being capped/throttled by uclamp_max? */ static inline bool uclamp_rq_is_capped(struct rq *rq) { @@ -3148,13 +3095,6 @@ static inline unsigned long uclamp_eff_value(struct task_struct *p, return SCHED_CAPACITY_SCALE; } -static inline -unsigned long uclamp_rq_util_with(struct rq *rq, unsigned long util, - struct task_struct *p) -{ - return util; -} - static inline bool uclamp_rq_is_capped(struct rq *rq) { return false; } static inline bool uclamp_is_used(void) -- cgit