Re: [PATCH] cpufreq: schedutil: Always trace frequency if it does not change

Viresh Kumar
2017-03-22T04:16:57Z

On 22-03-17, 01:56, Rafael J. Wysocki wrote:
> From: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
>
> sugov_update_commit() calls trace_cpu_frequency() to record the
> current CPU frequency if it has not changed in the fast switch case
> to prevent utilities from getting confused (they may report that the
> CPU is idle if the frequency has not been recorded for too long, for
> example).
>
> However, the same problem may occur for a cpufreq driver that doesn't
> support fast frequency switching and implements the ->target callback
> (that is, it doesn't use frequency tables), but trace_cpu_frequency()
> is not called if frequency updates are skipped in that case.
>
> For this reason, modify sugov_update_commit() to always call
> trace_cpu_frequency() when the new frequency to be set is equal to
> the one that was set previously and reorganize the code in there to
> reduce duplication somewhat.
>
> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
> ---
> kernel/sched/cpufreq_schedutil.c | 18 +++++++++---------
> 1 file changed, 9 insertions(+), 9 deletions(-)

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

--
viresh