On Mon, Nov 30, 2020 at 07:37:01PM +0100, Rafael J. Wysocki wrote:
> From: Rafael J. Wysocki <rafael.j.wyso...@intel.com>
>
> First off, some cpufreq drivers (eg. intel_pstate) can pass hints
> beyond the current target frequency to the hardware and there are no
Everything CPPC, which is quite a bit these days.
> + /*
> + * ->fast_switch() replacement for drivers that use an internal
> + * representation of performance levels and can pass hints other than
> + * the target performance level to the hardware.
> + */
> + void (*adjust_perf)(unsigned int cpu, bool busy,
> + unsigned long min_perf,
> + unsigned long target_perf,
> + unsigned long capacity);
>
I'm not sure @busy makes sense, that's more a hack because @util had a
dip and should remain inside schedutil.
> @@ -454,6 +455,25 @@ static void sugov_update_single(struct u
> util = sugov_get_util(sg_cpu);
> max = sg_cpu->max;
> util = sugov_iowait_apply(sg_cpu, time, util, max);
> +
> + /*
> + * This code runs under rq->lock for the target CPU, so it won't run
> + * concurrently on two different CPUs for the same target and it is not
> + * necessary to acquire the lock in the fast switch case.
> + */
> + if (sg_policy->direct_fast_switch) {
> + /*
> + * In this case, any optimizations that can be done are up to
> + * the driver.
> + */
> + cpufreq_driver_adjust_perf(sg_cpu->cpu,
> + sugov_cpu_is_busy(sg_cpu),
> + map_util_perf(sg_cpu->bw_dl),
> + map_util_perf(util), max);
> + sg_policy->last_freq_update_time = time;
> + return;
> + }
Instead of adding more branches, would it makes sense to simply set a
whole different util_hook in this case?
