Re: [PATCH] cpufreq: conservative: Do not use transition notifications

From: Viresh Kumar
Date: Mon Jun 13 2016 - 11:28:44 EST


On 13-06-16, 15:36, Rafael J. Wysocki wrote:
> From: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx>
> Subject: [PATCH v2] cpufreq: conservative: Do not use transition notifications
>
> The conservative governor registers a transition notifier so it
> can update its internal requested_freq value if it falls out of the
> policy->min...policy->max range, but requested_freq is not really
> necessary.
>
> That value is used to track the frequency requested by the governor
> previously, but policy->cur can be used instead of it and then the
> governor will not have to worry about updating the tracked value when
> the current frequency changes independently (for example, as a result
> of min or max changes).
>
> Accodringly, drop requested_freq from struct cs_policy_dbs_info
> and modify cs_dbs_timer() to use policy->cur instead of it.
> While at it, notice that __cpufreq_driver_target() clamps its
> target_freq argument between policy->min and policy->max, so
> the callers of it don't have to do that and make additional
> changes in cs_dbs_timer() in accordance with that.
>
> After these changes the transition notifier used by the conservative
> governor is not necessary any more, so drop it, which also makes it
> possible to drop the struct cs_governor definition and simplify the
> code accordingly.
>
> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx>
> ---
> drivers/cpufreq/cpufreq_conservative.c | 103 ++++++---------------------------
> 1 file changed, 21 insertions(+), 82 deletions(-)
>

Acked-by: Viresh Kumar <viresh.kumar@xxxxxxxxxx>

> -static struct cs_governor cs_gov = {
> - .dbs_gov = {
> - .gov = CPUFREQ_DBS_GOVERNOR_INITIALIZER("conservative"),
> - .kobj_type = { .default_attrs = cs_attributes },
> - .gov_dbs_timer = cs_dbs_timer,
> - .alloc = cs_alloc,
> - .free = cs_free,
> - .init = cs_init,
> - .exit = cs_exit,
> - .start = cs_start,
> - },
> +static struct dbs_governor cs_governor = {
> + .gov = CPUFREQ_DBS_GOVERNOR_INITIALIZER("conservative"),
> + .kobj_type = { .default_attrs = cs_attributes },
> + .gov_dbs_timer = cs_dbs_timer,
> + .alloc = cs_alloc,
> + .free = cs_free,
> + .init = cs_init,
> + .exit = cs_exit,
> + .start = cs_start,
> };

Though, I am not sure why this change was required :)

--
viresh