Messages in this thread Patch in this message | | | Subject | Re: [RFC PATCH 1/6] sched/dl: Improve deadline admission control for asymmetric CPU capacities | From | Dietmar Eggemann <> | Date | Mon, 8 Jul 2019 13:22:35 +0200 |
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On 5/7/19 4:43 PM, luca abeni wrote: > On Tue, 7 May 2019 15:31:27 +0100 > Quentin Perret <quentin.perret@arm.com> wrote: > >> On Tuesday 07 May 2019 at 16:25:23 (+0200), luca abeni wrote: >>> On Tue, 7 May 2019 14:48:52 +0100 >>> Quentin Perret <quentin.perret@arm.com> wrote: >>> >>>> Hi Luca, >>>> >>>> On Monday 06 May 2019 at 06:48:31 (+0200), Luca Abeni wrote:
[...]
>> Right and things moved recently in this area, see bb1fbdd3c3fd >> ("sched/topology, drivers/base/arch_topology: Rebuild the sched_domain >> hierarchy when capacities change") > > Ah, thanks! I missed this change when rebasing the patchset. > I guess this part of the patch has to be updated (and probably became > useless?), then.
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>>> This achieved the effect of correctly setting up the "rd_capacity" >>> field, but I do not know if there is a better/simpler way to achieve >>> the same result :) >> >> OK, that's really an implementation detail, so no need to worry too >> much about it at the RFC stage I suppose :-)
What about we integrate the code to calculate the rd capacity into build_sched_domains() (next to the code to establish the rd max_cpu_capacity)?
root@juno:~# cat /sys/devices/system/cpu/cpu*/cpu_capacity 446 1024 1024 446 446 446
root@juno:~# dmesg | grep "rd capacity" /* before CPUfreq max CPU freq calibration */ [ 0.749389] rd span: 0-5 rd capacity: 4360 max cpu_capacity: 1024 /* after CPUfreq max CPU freq calibration */ [ 3.372759] rd span: 0-5 rd capacity: 3832 max cpu_capacity: 1024
/* 2*1024 + 4*446 = 3832 */
root@juno:~# echo 0 > /sys/devices/system/cpu/cpu5/online
root@juno:~# dmesg | grep "rd capacity" ... [ 2715.068198] rd span: 0-4 rd capacity: 3386 max cpu_capacity: 1024
root@juno:~# echo 1 > /sys/devices/system/cpu/cpu5/online
root@juno:~# dmesg | grep "rd capacity" ... [ 2807.200662] rd span: 0-5 rd capacity: 3832 max cpu_capacity: 1024
--->8---
@@ -768,6 +769,7 @@ struct root_domain { cpumask_var_t rto_mask; struct cpupri cpupri; + unsigned long capacity; unsigned long max_cpu_capacity; /* diff --git a/kernel/sched/topology.c b/kernel/sched/topology.c index f751ce0b783e..68acdca27eaf 100644 --- a/kernel/sched/topology.c +++ b/kernel/sched/topology.c @@ -2000,6 +2000,9 @@ build_sched_domains(const struct cpumask *cpu_map, struct sched_domain_attr *att if (rq->cpu_capacity_orig > READ_ONCE(d.rd->max_cpu_capacity)) WRITE_ONCE(d.rd->max_cpu_capacity, rq->cpu_capacity_orig); + WRITE_ONCE(d.rd->capacity, + READ_ONCE(d.rd->capacity) + rq->cpu_capacity_orig); + cpu_attach_domain(sd, d.rd, i); } rcu_read_unlock(); @@ -2008,8 +2011,9 @@ build_sched_domains(const struct cpumask *cpu_map, struct sched_domain_attr *att static_branch_enable_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("rd span: %*pbl rd capacity: %lu max cpu_capacity: %lu\n", + cpumask_pr_args(cpu_map), rq->rd->capacity, + rq->rd->max_cpu_capacity); }
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