On Thursday, March 09, 2017 05:15:13 PM Viresh Kumar wrote:
> On many platforms any CPU (from any cpufreq policy) can perform DVFS on
> behalf of other CPUs. Add a flag to identify such cpufreq policies.
>
> Also enable it for cpufreq-dt driver which is used only on ARM platforms
> currently.
>
> Signed-off-by: Viresh Kumar <viresh.ku...@linaro.org>
> ---
> drivers/cpufreq/cpufreq-dt.c | 1 +
> include/linux/cpufreq.h | 9 +++++++++
> 2 files changed, 10 insertions(+)
>
> diff --git a/drivers/cpufreq/cpufreq-dt.c b/drivers/cpufreq/cpufreq-dt.c
> index c943787d761e..e57b45f20544 100644
> --- a/drivers/cpufreq/cpufreq-dt.c
> +++ b/drivers/cpufreq/cpufreq-dt.c
> @@ -274,6 +274,7 @@ static int cpufreq_init(struct cpufreq_policy *policy)
> transition_latency = CPUFREQ_ETERNAL;
>
> policy->cpuinfo.transition_latency = transition_latency;
> + policy->dvfs_possible_from_any_cpu = true;
>
> return 0;
>
> diff --git a/include/linux/cpufreq.h b/include/linux/cpufreq.h
> index 87165f06a307..9490a314c515 100644
> --- a/include/linux/cpufreq.h
> +++ b/include/linux/cpufreq.h
> @@ -120,6 +120,15 @@ struct cpufreq_policy {
> bool fast_switch_possible;
> bool fast_switch_enabled;
>
> + /*
> + * Remote DVFS flag (Not added to the driver structure as we don't want
> + * to access another structure from scheduler hotpath).
> + *
> + * Should be set if any CPU (from same or different policy) can do DVFS
> + * on behalf of any other CPU.
> + */
> + bool dvfs_possible_from_any_cpu;
We rely on the assumption that any CPU in a policy can do DVFS in there already.
Why is this flag necessary at all?
> +
> /* Cached frequency lookup from cpufreq_driver_resolve_freq. */
> unsigned int cached_target_freq;
> int cached_resolved_idx;
>
Thanks,
Rafael
