Messages in this thread Patch in this message | | | From | Abel Wu <> | Subject | [PATCH 1/5] sched/fair: ignore SIS_UTIL when has idle core | Date | Tue, 12 Jul 2022 16:20:32 +0800 |
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When SIS_UTIL is enabled, SIS domain scan will be skipped if the LLC is overloaded. Since the overloaded status is checked in the load balancing at LLC level, the interval is llc_size miliseconds. The duration might be long enough to affect the overall system throughput if idle cores are out of reach in SIS domain scan.
Signed-off-by: Abel Wu <wuyun.abel@bytedance.com> --- kernel/sched/fair.c | 15 +++++++++------ 1 file changed, 9 insertions(+), 6 deletions(-)
diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c index a78d2e3b9d49..cd758b3616bd 100644 --- a/kernel/sched/fair.c +++ b/kernel/sched/fair.c @@ -6392,16 +6392,19 @@ static int select_idle_cpu(struct task_struct *p, struct sched_domain *sd, bool struct sched_domain *this_sd; u64 time = 0; - this_sd = rcu_dereference(*this_cpu_ptr(&sd_llc)); - if (!this_sd) - return -1; - cpumask_and(cpus, sched_domain_span(sd), p->cpus_ptr); - if (sched_feat(SIS_PROP) && !has_idle_core) { + if (has_idle_core) + goto scan; + + if (sched_feat(SIS_PROP)) { 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 @@ -6436,7 +6439,7 @@ static int select_idle_cpu(struct task_struct *p, struct sched_domain *sd, bool return -1; } } - +scan: for_each_cpu_wrap(cpu, cpus, target + 1) { if (has_idle_core) { i = select_idle_core(p, cpu, cpus, &idle_cpu); -- 2.31.1
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