Re: [PATCH 2/2] trace: power allocator: add trace for divvyup algorithm

[Lukasz Luba <lukasz.luba@arm.com>]

Hi Steven,

On 08/05/17 14:44, Steven Rostedt wrote:
> On Mon,  8 May 2017 14:40:02 +0100
> Lukasz Luba <lukasz.luba@arm.com> wrote:
>
>> This trace function helps to figure out the divvyup algorithm
>> on some platforms.
>>
>> CC: Steven Rostedt <rostedt@goodmis.org>
>> CC: Ingo Molnar <mingo@redhat.com>
>> CC: Zhang Rui <rui.zhang@intel.com>
>> CC: Eduardo Valentin <edubezval@gmail.com>
>> Signed-off-by: Lukasz Luba <lukasz.luba@arm.com>
>> ---
>>  drivers/thermal/power_allocator.c              |  4 +++
>>  include/trace/events/thermal_power_allocator.h | 40 ++++++++++++++++++++++++++
>>  2 files changed, 44 insertions(+)
>>
>> diff --git a/drivers/thermal/power_allocator.c b/drivers/thermal/power_allocator.c
>> index db74e05..b71125a 100644
>> --- a/drivers/thermal/power_allocator.c
>> +++ b/drivers/thermal/power_allocator.c
>> @@ -331,6 +331,10 @@ static void siblings_grants(struct thermal_zone_device *tz,
>>  		total_avail_room += avail_room[i];
>>  	}
>>
>> +	trace_thermal_power_allocator_divvyup(tz, granted_power, avail_room,
>> +					      spare_power, max_power,
>> +					      num_actors);
>
> I'm curious, how big can "num_actors" be?
That's a good question.
Normally max is around 5 (2 CPU clusters + 3 devfreq devices).
However, when you have per-core DVFS for CPUs
and you have N cores (i.e. 32), then you can register N cooling
devices for them.
>
> -- Steve
>
>> +
>>  	/* Share the extra power inside the same family. */
>>  	for (i = 0; i < num_actors; i++) {
>>  		u32 power;
>> diff --git a/include/trace/events/thermal_power_allocator.h b/include/trace/events/thermal_power_allocator.h
>> index 5afae8f..03f224b 100644
>> --- a/include/trace/events/thermal_power_allocator.h
>> +++ b/include/trace/events/thermal_power_allocator.h
>> @@ -54,6 +54,46 @@
>>  		__entry->delta_temp)
>>  );
>>
>> +TRACE_EVENT(thermal_power_allocator_divvyup,
>> +	TP_PROTO(struct thermal_zone_device *tz, u32 *granted_power,
>> +		u32 *avail_room, u32 *spare_power, u32 *max_power,
>> +		size_t num_actors),
>> +	TP_ARGS(tz, granted_power, avail_room, spare_power, max_power,
>> +		num_actors),
>> +	TP_STRUCT__entry(
>> +		__field(int, tz_id)
>> +		__dynamic_array(u32, granted_power, num_actors)
>> +		__dynamic_array(u32, avail_room, num_actors)
>> +		__dynamic_array(u32, spare_power, num_actors)
>> +		__dynamic_array(u32, max_power, num_actors)
>> +		__field(size_t, num_actors)
>> +	),
>> +	TP_fast_assign(
>> +		__entry->tz_id = tz->id;
>> +		memcpy(__get_dynamic_array(granted_power), granted_power,
>> +			num_actors * sizeof(*granted_power));
>> +		memcpy(__get_dynamic_array(avail_room), avail_room,
>> +			num_actors * sizeof(*avail_room));
>> +		memcpy(__get_dynamic_array(spare_power), spare_power,
>> +			num_actors * sizeof(*spare_power));
>> +		memcpy(__get_dynamic_array(max_power), max_power,
>> +			num_actors * sizeof(*max_power));
>> +		__entry->num_actors = num_actors;
>> +	),
>> +
>> +	TP_printk("thermal_zone_id=%d granted_power={%s} avail_room={%s} spare_power={%s} max_power={%s}",
>> +		__entry->tz_id,
>> +		__print_array(__get_dynamic_array(granted_power),
>> +			      __entry->num_actors, 4),
>> +		__print_array(__get_dynamic_array(avail_room),
>> +			      __entry->num_actors, 4),
>> +		__print_array(__get_dynamic_array(spare_power),
>> +			      __entry->num_actors, 4),
>> +		__print_array(__get_dynamic_array(max_power),
>> +			      __entry->num_actors, 4)
>> +		)
>> +);
>> +
>>  TRACE_EVENT(thermal_power_allocator_pid,
>>  	TP_PROTO(struct thermal_zone_device *tz, s32 err, s32 err_integral,
>>  		 s64 p, s64 i, s64 d, s32 output),
>

Regards,
Lukasz