Messages in this thread Patch in this message | | | Date | Tue, 22 Mar 2022 10:25:45 +0100 | From | Dietmar Eggemann <> | Subject | Re: [PATCH v3 6/7] sched/fair: Remove task_util from effective utilization in feec() |
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On 08/03/2022 19:19, Vincent Donnefort wrote:
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> Signed-off-by: Vincent Donnefort <vincent.donnefort@arm.com>
LGTM, just a couple of small remarks.
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> @@ -6681,9 +6735,11 @@ static int find_energy_efficient_cpu(struct task_struct *p, int prev_cpu) > unsigned long prev_delta = ULONG_MAX, best_delta = ULONG_MAX; > struct root_domain *rd = cpu_rq(smp_processor_id())->rd;
s/cpu_rq(smp_processor_id())/this_rq()
Maybe you can clean this up with this patch?
> int cpu, best_energy_cpu = prev_cpu, target = -1; > - unsigned long cpu_cap, util, base_energy = 0; > + unsigned long cpu_cap, cpu_thermal_cap, util;
cpu_cap, cpu_thermal_cap and util can be defined inside the `for (; pd; pd = pd->next)` scope below.
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> @@ -6706,6 +6762,8 @@ static int find_energy_efficient_cpu(struct task_struct *p, int prev_cpu) > if (!task_util_est(p)) > goto unlock; > > + eenv_task_busy_time(&eenv, p, prev_cpu); > + > for (; pd; pd = pd->next) { > unsigned long cur_delta, spare_cap, max_spare_cap = 0;
cpu_cap and spare_cap could be combined into one to save on local variables. E.g. cpu_cap
@@ -6908,8 +6908,6 @@ static int find_energy_efficient_cpu(struct task_struct *p, int prev_cpu) util = cpu_util_next(cpu, p, cpu); cpu_cap = capacity_of(cpu); - spare_cap = cpu_cap; - lsub_positive(&spare_cap, util); /* * Skip CPUs that cannot satisfy the capacity request. @@ -6922,15 +6920,14 @@ static int find_energy_efficient_cpu(struct task_struct *p, int prev_cpu) if (!fits_capacity(util, cpu_cap)) continue; + lsub_positive(&cpu_cap, util); + if (cpu == prev_cpu) { /* Always use prev_cpu as a candidate. */ compute_prev_delta = true; - } else if (spare_cap > max_spare_cap) { - /* - * Find the CPU with the maximum spare capacity - * in the performance domain. - */ - max_spare_cap = spare_cap; + } else if (cpu_cap > max_spare_cap) { + /* Find CPU with max spare capacity in PD. */ + max_spare_cap = cpu_cap; max_spare_cap_cpu = cpu; }
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