On 03/29/2016 07:00 PM, Rafael J. Wysocki wrote:
...
> +config CPU_FREQ_GOV_SCHEDUTIL
> + tristate "'schedutil' cpufreq policy governor"
> + depends on CPU_FREQ
> + select CPU_FREQ_GOV_ATTR_SET
> + select IRQ_WORK
> + help
> + This governor makes decisions based on the utilization data provided
> + by the scheduler. It sets the CPU frequency to be proportional to
> + the utilization/capacity ratio coming from the scheduler. If the
> + utilization is frequency-invariant, the new frequency is also
> + proportional to the maximum available frequency. If that is not the
> + case, it is proportional to the current frequency of the CPU with the
> + tipping point at utilization/capacity equal to 80%.
This help text implies that the tipping point of 80% applies only to
non-frequency invariant configurations, rather than both. Possible to
rephrase?
...
> +static unsigned int sugov_next_freq_shared(struct sugov_policy *sg_policy,
> + unsigned long util, unsigned long
> max)
> +{
> + struct cpufreq_policy *policy = sg_policy->policy;
> + unsigned int max_f = policy->cpuinfo.max_freq;
> + u64 last_freq_update_time = sg_policy->last_freq_update_time;
> + unsigned int j;
> +
> + if (util == ULONG_MAX)
> + return max_f;
> +
> + for_each_cpu(j, policy->cpus) {
> + struct sugov_cpu *j_sg_cpu;
> + unsigned long j_util, j_max;
> + u64 delta_ns;
> +
> + if (j == smp_processor_id())
> + continue;
> +
> + j_sg_cpu = &per_cpu(sugov_cpu, j);
> + /*
> + * If the CPU utilization was last updated before the previous
> + * frequency update and the time elapsed between the last update
> + * of the CPU utilization and the last frequency update is long
> + * enough, don't take the CPU into account as it probably is
> + * idle now.
> + */
> + delta_ns = last_freq_update_time - j_sg_cpu->last_update;
> + if ((s64)delta_ns > TICK_NSEC)
>> Why not declare delta_ns as an s64 (also in suguv_should_update_freq)
>> and avoid the cast?
>
> I took this from __update_load_avg(), but it shouldn't matter here.
Did you mean to keep these casts?
thanks,
Steve
