| Message ID | 20231020134337.GD33965@noisy.programming.kicks-ass.net (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | sched/fair: Remove SIS_PROP | expand |
On Fri, 20 Oct 2023 at 15:44, Peter Zijlstra <peterz@infradead.org> wrote: > > > > Since this had me looking at all that code, I did the below. > > Holler if there's objections etc.. > > --- > Subject: sched/fair: Remove SIS_PROP > From: Peter Zijlstra <peterz@infradead.org> > Date: Fri Oct 20 12:35:33 CEST 2023 > > SIS_UTIL seems to work well, lets remove the old thing. > > Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Vincent Guittot <vincent.guittot@linaro.org> > --- > include/linux/sched/topology.h | 2 - > kernel/sched/core.c | 5 ---- > kernel/sched/fair.c | 48 ----------------------------------------- > kernel/sched/features.h | 1 > kernel/sched/sched.h | 3 -- > 5 files changed, 59 deletions(-) > > --- a/include/linux/sched/topology.h > +++ b/include/linux/sched/topology.h > @@ -109,8 +109,6 @@ struct sched_domain { > u64 max_newidle_lb_cost; > unsigned long last_decay_max_lb_cost; > > - u64 avg_scan_cost; /* select_idle_sibling */ > - > #ifdef CONFIG_SCHEDSTATS > /* load_balance() stats */ > unsigned int lb_count[CPU_MAX_IDLE_TYPES]; > --- a/kernel/sched/core.c > +++ b/kernel/sched/core.c > @@ -3792,9 +3792,6 @@ ttwu_do_activate(struct rq *rq, struct t > if (rq->avg_idle > max) > rq->avg_idle = max; > > - rq->wake_stamp = jiffies; > - rq->wake_avg_idle = rq->avg_idle / 2; > - > rq->idle_stamp = 0; > } > #endif > @@ -9991,8 +9988,6 @@ void __init sched_init(void) > rq->online = 0; > rq->idle_stamp = 0; > rq->avg_idle = 2*sysctl_sched_migration_cost; > - rq->wake_stamp = jiffies; > - rq->wake_avg_idle = rq->avg_idle; > rq->max_idle_balance_cost = sysctl_sched_migration_cost; > > INIT_LIST_HEAD(&rq->cfs_tasks); > --- a/kernel/sched/fair.c > +++ b/kernel/sched/fair.c > @@ -7209,45 +7209,9 @@ static int select_idle_cpu(struct task_s > struct cpumask *cpus = this_cpu_cpumask_var_ptr(select_rq_mask); > int i, cpu, idle_cpu = -1, nr = INT_MAX; > struct sched_domain_shared *sd_share; > - struct rq *this_rq = this_rq(); > - int this = smp_processor_id(); > - struct sched_domain *this_sd = NULL; > - u64 time = 0; > > cpumask_and(cpus, sched_domain_span(sd), p->cpus_ptr); > > - if (sched_feat(SIS_PROP) && !has_idle_core) { > - u64 avg_cost, avg_idle, span_avg; > - unsigned long now = jiffies; > - > - this_sd = rcu_dereference(*this_cpu_ptr(&sd_llc)); > - if (!this_sd) > - return -1; > - > - /* > - * If we're busy, the assumption that the last idle period > - * predicts the future is flawed; age away the remaining > - * predicted idle time. > - */ > - if (unlikely(this_rq->wake_stamp < now)) { > - while (this_rq->wake_stamp < now && this_rq->wake_avg_idle) { > - this_rq->wake_stamp++; > - this_rq->wake_avg_idle >>= 1; > - } > - } > - > - avg_idle = this_rq->wake_avg_idle; > - avg_cost = this_sd->avg_scan_cost + 1; > - > - span_avg = sd->span_weight * avg_idle; > - if (span_avg > 4*avg_cost) > - nr = div_u64(span_avg, avg_cost); > - else > - nr = 4; > - > - time = cpu_clock(this); > - } > - > if (sched_feat(SIS_UTIL)) { > sd_share = rcu_dereference(per_cpu(sd_llc_shared, target)); > if (sd_share) { > @@ -7301,18 +7265,6 @@ static int select_idle_cpu(struct task_s > if (has_idle_core) > set_idle_cores(target, false); > > - if (sched_feat(SIS_PROP) && this_sd && !has_idle_core) { > - time = cpu_clock(this) - time; > - > - /* > - * Account for the scan cost of wakeups against the average > - * idle time. > - */ > - this_rq->wake_avg_idle -= min(this_rq->wake_avg_idle, time); > - > - update_avg(&this_sd->avg_scan_cost, time); > - } > - > return idle_cpu; > } > > --- a/kernel/sched/features.h > +++ b/kernel/sched/features.h > @@ -49,7 +49,6 @@ SCHED_FEAT(TTWU_QUEUE, true) > /* > * When doing wakeups, attempt to limit superfluous scans of the LLC domain. > */ > -SCHED_FEAT(SIS_PROP, false) > SCHED_FEAT(SIS_UTIL, true) > > /* > --- a/kernel/sched/sched.h > +++ b/kernel/sched/sched.h > @@ -1059,9 +1059,6 @@ struct rq { > u64 idle_stamp; > u64 avg_idle; > > - unsigned long wake_stamp; > - u64 wake_avg_idle; > - > /* This is used to determine avg_idle's max value */ > u64 max_idle_balance_cost; > > > _______________________________________________ > linux-arm-kernel mailing list > linux-arm-kernel@lists.infradead.org > http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
On 2023/10/20 21:43, Peter Zijlstra wrote: > > > Since this had me looking at all that code, I did the below. > > Holler if there's objections etc.. > > --- > Subject: sched/fair: Remove SIS_PROP > From: Peter Zijlstra <peterz@infradead.org> > Date: Fri Oct 20 12:35:33 CEST 2023 > > SIS_UTIL seems to work well, lets remove the old thing. > > Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> SIS_UTIL works fine on my machine, so Reviewed-by: Yicong Yang <yangyicong@hisilicon.com> > --- > include/linux/sched/topology.h | 2 - > kernel/sched/core.c | 5 ---- > kernel/sched/fair.c | 48 ----------------------------------------- > kernel/sched/features.h | 1 > kernel/sched/sched.h | 3 -- > 5 files changed, 59 deletions(-) > > --- a/include/linux/sched/topology.h > +++ b/include/linux/sched/topology.h > @@ -109,8 +109,6 @@ struct sched_domain { > u64 max_newidle_lb_cost; > unsigned long last_decay_max_lb_cost; > > - u64 avg_scan_cost; /* select_idle_sibling */ > - > #ifdef CONFIG_SCHEDSTATS > /* load_balance() stats */ > unsigned int lb_count[CPU_MAX_IDLE_TYPES]; > --- a/kernel/sched/core.c > +++ b/kernel/sched/core.c > @@ -3792,9 +3792,6 @@ ttwu_do_activate(struct rq *rq, struct t > if (rq->avg_idle > max) > rq->avg_idle = max; > > - rq->wake_stamp = jiffies; > - rq->wake_avg_idle = rq->avg_idle / 2; > - > rq->idle_stamp = 0; > } > #endif > @@ -9991,8 +9988,6 @@ void __init sched_init(void) > rq->online = 0; > rq->idle_stamp = 0; > rq->avg_idle = 2*sysctl_sched_migration_cost; > - rq->wake_stamp = jiffies; > - rq->wake_avg_idle = rq->avg_idle; > rq->max_idle_balance_cost = sysctl_sched_migration_cost; > > INIT_LIST_HEAD(&rq->cfs_tasks); > --- a/kernel/sched/fair.c > +++ b/kernel/sched/fair.c > @@ -7209,45 +7209,9 @@ static int select_idle_cpu(struct task_s > struct cpumask *cpus = this_cpu_cpumask_var_ptr(select_rq_mask); > int i, cpu, idle_cpu = -1, nr = INT_MAX; > struct sched_domain_shared *sd_share; > - struct rq *this_rq = this_rq(); > - int this = smp_processor_id(); > - struct sched_domain *this_sd = NULL; > - u64 time = 0; > > cpumask_and(cpus, sched_domain_span(sd), p->cpus_ptr); > > - if (sched_feat(SIS_PROP) && !has_idle_core) { > - u64 avg_cost, avg_idle, span_avg; > - unsigned long now = jiffies; > - > - this_sd = rcu_dereference(*this_cpu_ptr(&sd_llc)); > - if (!this_sd) > - return -1; > - > - /* > - * If we're busy, the assumption that the last idle period > - * predicts the future is flawed; age away the remaining > - * predicted idle time. > - */ > - if (unlikely(this_rq->wake_stamp < now)) { > - while (this_rq->wake_stamp < now && this_rq->wake_avg_idle) { > - this_rq->wake_stamp++; > - this_rq->wake_avg_idle >>= 1; > - } > - } > - > - avg_idle = this_rq->wake_avg_idle; > - avg_cost = this_sd->avg_scan_cost + 1; > - > - span_avg = sd->span_weight * avg_idle; > - if (span_avg > 4*avg_cost) > - nr = div_u64(span_avg, avg_cost); > - else > - nr = 4; > - > - time = cpu_clock(this); > - } > - > if (sched_feat(SIS_UTIL)) { > sd_share = rcu_dereference(per_cpu(sd_llc_shared, target)); > if (sd_share) { > @@ -7301,18 +7265,6 @@ static int select_idle_cpu(struct task_s > if (has_idle_core) > set_idle_cores(target, false); > > - if (sched_feat(SIS_PROP) && this_sd && !has_idle_core) { > - time = cpu_clock(this) - time; > - > - /* > - * Account for the scan cost of wakeups against the average > - * idle time. > - */ > - this_rq->wake_avg_idle -= min(this_rq->wake_avg_idle, time); > - > - update_avg(&this_sd->avg_scan_cost, time); > - } > - > return idle_cpu; > } > > --- a/kernel/sched/features.h > +++ b/kernel/sched/features.h > @@ -49,7 +49,6 @@ SCHED_FEAT(TTWU_QUEUE, true) > /* > * When doing wakeups, attempt to limit superfluous scans of the LLC domain. > */ > -SCHED_FEAT(SIS_PROP, false) > SCHED_FEAT(SIS_UTIL, true) > > /* > --- a/kernel/sched/sched.h > +++ b/kernel/sched/sched.h > @@ -1059,9 +1059,6 @@ struct rq { > u64 idle_stamp; > u64 avg_idle; > > - unsigned long wake_stamp; > - u64 wake_avg_idle; > - > /* This is used to determine avg_idle's max value */ > u64 max_idle_balance_cost; > >
On Fri, Oct 20, 2023 at 03:43:37PM +0200, Peter Zijlstra wrote: > > > Since this had me looking at all that code, I did the below. > > Holler if there's objections etc.. > > --- > Subject: sched/fair: Remove SIS_PROP > From: Peter Zijlstra <peterz@infradead.org> > Date: Fri Oct 20 12:35:33 CEST 2023 > > SIS_UTIL seems to work well, lets remove the old thing. > > Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Mel Gorman <mgorman@suse.de>
--- a/include/linux/sched/topology.h +++ b/include/linux/sched/topology.h @@ -109,8 +109,6 @@ struct sched_domain { u64 max_newidle_lb_cost; unsigned long last_decay_max_lb_cost; - u64 avg_scan_cost; /* select_idle_sibling */ - #ifdef CONFIG_SCHEDSTATS /* load_balance() stats */ unsigned int lb_count[CPU_MAX_IDLE_TYPES]; --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -3792,9 +3792,6 @@ ttwu_do_activate(struct rq *rq, struct t if (rq->avg_idle > max) rq->avg_idle = max; - rq->wake_stamp = jiffies; - rq->wake_avg_idle = rq->avg_idle / 2; - rq->idle_stamp = 0; } #endif @@ -9991,8 +9988,6 @@ void __init sched_init(void) rq->online = 0; rq->idle_stamp = 0; rq->avg_idle = 2*sysctl_sched_migration_cost; - rq->wake_stamp = jiffies; - rq->wake_avg_idle = rq->avg_idle; rq->max_idle_balance_cost = sysctl_sched_migration_cost; INIT_LIST_HEAD(&rq->cfs_tasks); --- a/kernel/sched/fair.c +++ b/kernel/sched/fair.c @@ -7209,45 +7209,9 @@ static int select_idle_cpu(struct task_s struct cpumask *cpus = this_cpu_cpumask_var_ptr(select_rq_mask); int i, cpu, idle_cpu = -1, nr = INT_MAX; struct sched_domain_shared *sd_share; - struct rq *this_rq = this_rq(); - int this = smp_processor_id(); - struct sched_domain *this_sd = NULL; - u64 time = 0; cpumask_and(cpus, sched_domain_span(sd), p->cpus_ptr); - if (sched_feat(SIS_PROP) && !has_idle_core) { - u64 avg_cost, avg_idle, span_avg; - unsigned long now = jiffies; - - this_sd = rcu_dereference(*this_cpu_ptr(&sd_llc)); - if (!this_sd) - return -1; - - /* - * If we're busy, the assumption that the last idle period - * predicts the future is flawed; age away the remaining - * predicted idle time. - */ - if (unlikely(this_rq->wake_stamp < now)) { - while (this_rq->wake_stamp < now && this_rq->wake_avg_idle) { - this_rq->wake_stamp++; - this_rq->wake_avg_idle >>= 1; - } - } - - avg_idle = this_rq->wake_avg_idle; - avg_cost = this_sd->avg_scan_cost + 1; - - span_avg = sd->span_weight * avg_idle; - if (span_avg > 4*avg_cost) - nr = div_u64(span_avg, avg_cost); - else - nr = 4; - - time = cpu_clock(this); - } - if (sched_feat(SIS_UTIL)) { sd_share = rcu_dereference(per_cpu(sd_llc_shared, target)); if (sd_share) { @@ -7301,18 +7265,6 @@ static int select_idle_cpu(struct task_s if (has_idle_core) set_idle_cores(target, false); - if (sched_feat(SIS_PROP) && this_sd && !has_idle_core) { - time = cpu_clock(this) - time; - - /* - * Account for the scan cost of wakeups against the average - * idle time. - */ - this_rq->wake_avg_idle -= min(this_rq->wake_avg_idle, time); - - update_avg(&this_sd->avg_scan_cost, time); - } - return idle_cpu; } --- a/kernel/sched/features.h +++ b/kernel/sched/features.h @@ -49,7 +49,6 @@ SCHED_FEAT(TTWU_QUEUE, true) /* * When doing wakeups, attempt to limit superfluous scans of the LLC domain. */ -SCHED_FEAT(SIS_PROP, false) SCHED_FEAT(SIS_UTIL, true) /* --- a/kernel/sched/sched.h +++ b/kernel/sched/sched.h @@ -1059,9 +1059,6 @@ struct rq { u64 idle_stamp; u64 avg_idle; - unsigned long wake_stamp; - u64 wake_avg_idle; - /* This is used to determine avg_idle's max value */ u64 max_idle_balance_cost;