sched/fair: Remove SIS_PROP

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>
Link: https://lkml.kernel.org/r/20231020134337.GD33965@noisy.programming.kicks-ass.net

diff --git a/include/linux/sched/topology.h b/include/linux/sched/topology.h
index 4c14fe1..de545ba 100644 (file)
--- 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];

diff --git a/kernel/sched/core.c b/kernel/sched/core.c
index 5e1fb8a..7a0c161 100644 (file)
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -3792,9 +3792,6 @@ ttwu_do_activate(struct rq *rq, struct task_struct *p, int wake_flags,
                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
@@ -9953,8 +9950,6 @@ 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);

diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index 523b5ae..8767988 100644 (file)
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -7209,45 +7209,9 @@ static int select_idle_cpu(struct task_struct *p, struct sched_domain *sd, bool
        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_struct *p, struct sched_domain *sd, bool
        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;
 }
 

diff --git a/kernel/sched/features.h b/kernel/sched/features.h
index f770168..a3ddf84 100644 (file)
--- 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)
 
 /*

diff --git a/kernel/sched/sched.h b/kernel/sched/sched.h
index ef4fe7b..2e5a954 100644 (file)
--- 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;