diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c index ff69f245b939..852a048a5f8c 100644 --- a/kernel/sched/fair.c +++ b/kernel/sched/fair.c @@ -6265,10 +6265,10 @@ static inline int select_idle_smt(struct task_struct *p, struct sched_domain *sd static int select_idle_cpu(struct task_struct *p, struct sched_domain *sd, bool has_idle_core, int target) { struct cpumask *cpus = this_cpu_cpumask_var_ptr(select_idle_mask);
int i, cpu, idle_cpu = -1, nr = INT_MAX;
int i, cpu, scan_from, idle_cpu = -1, nr = INT_MAX;struct sched_domain *this_sd, *cluster_sd; struct rq *this_rq = this_rq(); int this = smp_processor_id();
struct sched_domain *this_sd; u64 time = 0; this_sd = rcu_dereference(*this_cpu_ptr(&sd_llc));@@ -6276,6 +6276,10 @@ static int select_idle_cpu(struct task_struct *p, struct sched_domain *sd, bool return -1;
cpumask_and(cpus, sched_domain_span(sd), p->cpus_ptr);
cpumask_clear_cpu(target, cpus);
May double test if it is necessary to clear the target as target can be idle after it was scanned.
cluster_sd = rcu_dereference(*this_cpu_ptr(&sd_cluster));
This line is wrong. should be:
diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c index 852a048..0a946ba 100644 --- a/kernel/sched/fair.c +++ b/kernel/sched/fair.c @@ -6278,7 +6278,7 @@ static int select_idle_cpu(struct task_struct *p, struct sched_domain *sd, bool cpumask_and(cpus, sched_domain_span(sd), p->cpus_ptr); cpumask_clear_cpu(target, cpus);
- cluster_sd = rcu_dereference(*this_cpu_ptr(&sd_cluster)); + cluster_sd = rcu_dereference(per_cpu(sd_cluster, target)); scan_from = cluster_sd ? cpumask_first(sched_domain_span(cluster_sd)) : target + 1;
testing needs to be done again with this fix.
scan_from = cluster_sd ? cpumask_first(sched_domain_span(cluster_sd)) : target + 1; if (sched_feat(SIS_PROP) && !has_idle_core) { u64 avg_cost, avg_idle, span_avg;@@ -6305,7 +6309,7 @@ static int select_idle_cpu(struct task_struct *p, struct sched_domain *sd, bool time = cpu_clock(this); }
for_each_cpu_wrap(cpu, cpus, target + 1) {
for_each_cpu_wrap(cpu, cpus, scan_from) { if (has_idle_core) { i = select_idle_core(p, cpu, cpus, &idle_cpu); if ((unsigned int)i < nr_cpumask_bits)-- 2.33.0
Thanks barry