From: Peter Zijlstra <peterz@infradead.org>
To: Yicong Yang <yangyicong@huawei.com>
Cc: mingo@redhat.com, juri.lelli@redhat.com,
vincent.guittot@linaro.org, dietmar.eggemann@arm.com,
tim.c.chen@linux.intel.com, yu.c.chen@intel.com,
gautham.shenoy@amd.com, mgorman@suse.de, vschneid@redhat.com,
linux-kernel@vger.kernel.org,
linux-arm-kernel@lists.infradead.org, rostedt@goodmis.org,
bsegall@google.com, bristot@redhat.com, prime.zeng@huawei.com,
yangyicong@hisilicon.com, jonathan.cameron@huawei.com,
ego@linux.vnet.ibm.com, srikar@linux.vnet.ibm.com,
linuxarm@huawei.com, 21cnbao@gmail.com, kprateek.nayak@amd.com,
wuyun.abel@bytedance.com, Barry Song <song.bao.hua@hisilicon.com>
Subject: Re: [PATCH v8 2/2] sched/fair: Scan cluster before scanning LLC in wake-up path
Date: Tue, 30 May 2023 13:55:27 +0200 [thread overview]
Message-ID: <20230530115527.GC156198@hirez.programming.kicks-ass.net> (raw)
In-Reply-To: <20230530070253.33306-3-yangyicong@huawei.com>
On Tue, May 30, 2023 at 03:02:53PM +0800, Yicong Yang wrote:
> diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
> index 373ff5f55884..b8c129ed8b47 100644
> --- a/kernel/sched/fair.c
> +++ b/kernel/sched/fair.c
> @@ -6994,6 +6994,30 @@ static int select_idle_cpu(struct task_struct *p, struct sched_domain *sd, bool
> }
> }
>
> + if (static_branch_unlikely(&sched_cluster_active)) {
> + struct sched_domain *sdc = rcu_dereference(per_cpu(sd_cluster, target));
> +
> + if (sdc) {
> + for_each_cpu_wrap(cpu, sched_domain_span(sdc), target + 1) {
> + if (!cpumask_test_cpu(cpu, cpus))
> + continue;
> +
> + if (has_idle_core) {
> + i = select_idle_core(p, cpu, cpus, &idle_cpu);
> + if ((unsigned int)i < nr_cpumask_bits)
> + return i;
> + } else {
> + if (--nr <= 0)
> + return -1;
> + idle_cpu = __select_idle_cpu(cpu, p);
> + if ((unsigned int)idle_cpu < nr_cpumask_bits)
> + return idle_cpu;
> + }
> + }
> + cpumask_andnot(cpus, cpus, sched_domain_span(sdc));
> + }
> + }
Would not this:
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -6994,6 +6994,29 @@ static int select_idle_cpu(struct task_s
}
}
+ if (static_branch_unlikely(&sched_cluster_active)) {
+ struct sched_group *sg = sd->groups;
+ if (sg->flags & SD_CLUSTER) {
+ for_each_cpu_wrap(cpu, sched_group_span(sg), target+1) {
+ if (!cpumask_test_cpu(cpu, cpus))
+ continue;
+
+ if (has_idle_core) {
+ i = select_idle_core(p, cpu, cpus, &idle_cpu);
+ if ((unsigned)i < nr_cpumask_bits)
+ return 1;
+ } else {
+ if (--nr <= 0)
+ return -1;
+ idle_cpu = __select_idle_cpu(cpu, p);
+ if ((unsigned)idle_cpu < nr_cpumask_bits)
+ return idle_cpu;
+ }
+ }
+ cpumask_andnot(cpus, cpus, sched_group_span(sg));
+ }
+ }
+
for_each_cpu_wrap(cpu, cpus, target + 1) {
if (has_idle_core) {
i = select_idle_core(p, cpu, cpus, &idle_cpu);
also work? Then we can avoid the extra sd_cluster per-cpu variable.
next prev parent reply other threads:[~2023-05-30 11:56 UTC|newest]
Thread overview: 19+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-05-30 7:02 [PATCH v8 0/2] sched/fair: Scan cluster before scanning LLC in wake-up path Yicong Yang
2023-05-30 7:02 ` [PATCH v8 1/2] sched: Add per_cpu cluster domain info and cpus_share_lowest_cache API Yicong Yang
2023-05-30 11:38 ` Peter Zijlstra
2023-05-30 13:24 ` Yicong Yang
2023-05-30 7:02 ` [PATCH v8 2/2] sched/fair: Scan cluster before scanning LLC in wake-up path Yicong Yang
2023-05-30 11:55 ` Peter Zijlstra [this message]
2023-05-30 14:39 ` Yicong Yang
2023-05-31 8:21 ` Yicong Yang
2023-06-08 3:26 ` Chen Yu
2023-06-08 6:45 ` Yicong Yang
2023-06-09 10:50 ` Chen Yu
2023-06-13 7:36 ` Yicong Yang
2023-06-13 8:09 ` Yicong Yang
2023-06-13 12:44 ` Chen Yu
2023-06-15 7:59 ` Yicong Yang
2023-06-16 6:00 ` Chen Yu
2023-06-12 5:01 ` Gautham R. Shenoy
2023-06-12 5:22 ` Chen Yu
2023-06-13 7:44 ` Yicong Yang
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