Re: [PATCH v2 3/3] sched/tp: Add new tracepoint to track compute energy computation

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

On 2/21/23 12:08, Qais Yousef wrote:
> On 02/20/23 11:22, Lukasz Luba wrote:
>> Hi Qais,
>>
>> On 2/5/23 22:43, Qais Yousef wrote:
>>> It was useful to track feec() placement decision and debug the spare
>>> capacity and optimization issues vs uclamp_max.
>>>
>>> Signed-off-by: Qais Yousef <qyousef@layalina.io>
>>> ---
>>>    include/trace/events/sched.h | 4 ++++
>>>    kernel/sched/core.c          | 1 +
>>>    kernel/sched/fair.c          | 7 ++++++-
>>>    3 files changed, 11 insertions(+), 1 deletion(-)
>>>
>>> diff --git a/include/trace/events/sched.h b/include/trace/events/sched.h
>>> index fbb99a61f714..20cc884f72ff 100644
>>> --- a/include/trace/events/sched.h
>>> +++ b/include/trace/events/sched.h
>>> @@ -735,6 +735,10 @@ DECLARE_TRACE(sched_update_nr_running_tp,
>>>    	TP_PROTO(struct rq *rq, int change),
>>>    	TP_ARGS(rq, change));
>>> +DECLARE_TRACE(sched_compute_energy_tp,
>>> +	TP_PROTO(struct task_struct *p, int dst_cpu, unsigned long energy),
>>> +	TP_ARGS(p, dst_cpu, energy));
>>> +
>>>    #endif /* _TRACE_SCHED_H */
>>>    /* This part must be outside protection */
>>> diff --git a/kernel/sched/core.c b/kernel/sched/core.c
>>> index 4580fe3e1d0c..5f6dde9b892b 100644
>>> --- a/kernel/sched/core.c
>>> +++ b/kernel/sched/core.c
>>> @@ -110,6 +110,7 @@ EXPORT_TRACEPOINT_SYMBOL_GPL(sched_overutilized_tp);
>>>    EXPORT_TRACEPOINT_SYMBOL_GPL(sched_util_est_cfs_tp);
>>>    EXPORT_TRACEPOINT_SYMBOL_GPL(sched_util_est_se_tp);
>>>    EXPORT_TRACEPOINT_SYMBOL_GPL(sched_update_nr_running_tp);
>>> +EXPORT_TRACEPOINT_SYMBOL_GPL(sched_compute_energy_tp);
>>>    DEFINE_PER_CPU_SHARED_ALIGNED(struct rq, runqueues);
>>> diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
>>> index a8c3d92ff3f6..801e903c4307 100644
>>> --- a/kernel/sched/fair.c
>>> +++ b/kernel/sched/fair.c
>>> @@ -7295,11 +7295,16 @@ compute_energy(struct energy_env *eenv, struct perf_domain *pd,
>>>    {
>>>    	unsigned long max_util = eenv_pd_max_util(eenv, pd_cpus, p, dst_cpu);
>>>    	unsigned long busy_time = eenv->pd_busy_time;
>>> +	unsigned long energy;
>>>    	if (dst_cpu >= 0)
>>>    		busy_time = min(eenv->pd_cap, busy_time + eenv->task_busy_time);
>>> -	return em_cpu_energy(pd->em_pd, max_util, busy_time, eenv->cpu_cap);
>>> +	energy = em_cpu_energy(pd->em_pd, max_util, busy_time, eenv->cpu_cap);
>>> +
>>> +	trace_sched_compute_energy_tp(p, dst_cpu, energy);
>>
>> Could we also dump the max_util and busy_time?
> 
> We certainly can :)

Great, thanks!