Re: [PATCH 2/4] sched: cpufreq: Keep track of cpufreq utilization update flags

On 18-Dec 17:29, Viresh Kumar wrote:

On 18-12-17, 12:35, Rafael J. Wysocki wrote:

quoted

Well, if SCHED_CPUFRREQ_CLEAR means "this CPU is going to enter the
idle loop" really, then it is better to call it
SCHED_CPUFRREQ_ENTER_IDLE, for example.

SCHED_CPUFRREQ_CLEAR meaning basically "you should clear these flags
now" doesn't seem to convey any information to whoever doesn't
squirrel the flags in the first place.

Right, but when all the flags are cleared, then we can infer that we
are going to idle in the most probable case.

Anyway, I will implement RT and DL clear flags as you suggested in the
next version.

I think Rafael is right, the current API is a big odd since we cannot
really set the CLEAR flags by itself. I mean, you can but it will not
have effects.

Thus, it's probably better from an API standpoint to have a dedicated
single clear flag... unfortunately it has to be one per class, which
is still not optimal and will likely make the policy code a bit odd.

What about extending the signature of the callback method?

For example, swithing from:

 - void (*func)(struct update_util_data *data, u64 time,
 -              unsigned int flags))
 + void (*func)(struct update_util_data *data, u64 time,
 +              unsigned int flags, bool set))

Where the additional boolean is actually used to define which
operation we wanna perform on the flags?

-- 
#include <best/regards.h>

Patrick Bellasi