Messages in this thread Patch in this message | | | From | Dietmar Eggemann <> | Subject | [PATCH v2 1/6] sched/topology: Store root domain CPU capacity sum | Date | Mon, 27 Apr 2020 10:37:04 +0200 |
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Add sum of (original) CPU capacity of all member CPUs to root domain.
This is needed for capacity-aware SCHED_DEADLINE admission control.
Signed-off-by: Dietmar Eggemann <dietmar.eggemann@arm.com> --- kernel/sched/sched.h | 1 + kernel/sched/topology.c | 15 +++++++++++---- 2 files changed, 12 insertions(+), 4 deletions(-)
diff --git a/kernel/sched/sched.h b/kernel/sched/sched.h index db3a57675ccf..58e1d3903ab9 100644 --- a/kernel/sched/sched.h +++ b/kernel/sched/sched.h @@ -803,6 +803,7 @@ struct root_domain { cpumask_var_t rto_mask; struct cpupri cpupri; + unsigned long sum_cpu_capacity; unsigned long max_cpu_capacity; /* diff --git a/kernel/sched/topology.c b/kernel/sched/topology.c index 8344757bba6e..fbb20b7a80c0 100644 --- a/kernel/sched/topology.c +++ b/kernel/sched/topology.c @@ -2052,12 +2052,18 @@ build_sched_domains(const struct cpumask *cpu_map, struct sched_domain_attr *att /* Attach the domains */ rcu_read_lock(); for_each_cpu(i, cpu_map) { + unsigned long cap; + rq = cpu_rq(i); sd = *per_cpu_ptr(d.sd, i); + cap = rq->cpu_capacity_orig; /* Use READ_ONCE()/WRITE_ONCE() to avoid load/store tearing: */ - if (rq->cpu_capacity_orig > READ_ONCE(d.rd->max_cpu_capacity)) - WRITE_ONCE(d.rd->max_cpu_capacity, rq->cpu_capacity_orig); + if (cap > READ_ONCE(d.rd->max_cpu_capacity)) + WRITE_ONCE(d.rd->max_cpu_capacity, cap); + + WRITE_ONCE(d.rd->sum_cpu_capacity, + READ_ONCE(d.rd->sum_cpu_capacity) + cap); cpu_attach_domain(sd, d.rd, i); } @@ -2067,8 +2073,9 @@ build_sched_domains(const struct cpumask *cpu_map, struct sched_domain_attr *att static_branch_inc_cpuslocked(&sched_asym_cpucapacity); if (rq && sched_debug_enabled) { - pr_info("root domain span: %*pbl (max cpu_capacity = %lu)\n", - cpumask_pr_args(cpu_map), rq->rd->max_cpu_capacity); + pr_info("root domain span: %*pbl (capacity = %lu max cpu_capacity = %lu)\n", + cpumask_pr_args(cpu_map), rq->rd->sum_cpu_capacity, + rq->rd->max_cpu_capacity); } ret = 0; -- 2.17.1
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