Re: [RFC/RFT][PATCH 1/2] cpufreq: schedutil: Use policy-dependent transition delays

From: Rafael J. Wysocki
Date: Tue Apr 11 2017 - 10:01:54 EST


On Tue, Apr 11, 2017 at 1:14 PM, Viresh Kumar <viresh.kumar@xxxxxxxxxx> wrote:
> On 11-04-17, 00:20, Rafael J. Wysocki wrote:
>> From: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx>
>>
>> Make the schedutil governor take the initial (default) value of the
>> rate_limit_us sysfs attribute from the (new) transition_delay_us
>> policy parameter (to be set by the scaling driver).
>>
>> That will allow scaling drivers to make schedutil use smaller default
>> values of rate_limit_us and reduce the default average time interval
>> between consecutive frequency changes.
>>
>> Make intel_pstate set transition_delay_us to 500.
>>
>> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx>
>> ---
>>
>> This is a replacement for https://patchwork.kernel.org/patch/9671831/
>>
>> ---
>> drivers/cpufreq/intel_pstate.c | 2 ++
>> include/linux/cpufreq.h | 7 +++++++
>> kernel/sched/cpufreq_schedutil.c | 15 ++++++++++-----
>> 3 files changed, 19 insertions(+), 5 deletions(-)
>
> Should we use this new value for the ondemand/conservative governors as well?

We might, but it is mostly for schedutil.

Thanks,
Rafael