Messages in this thread | | | Date | Tue, 11 Apr 2023 17:39:23 +0200 | Subject | Re: [PATCH 05/17] trace: energy_model: Add trace event for EM runtime modifications | From | Pierre Gondois <> |
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Hello Lukasz, Just a suggestion, maybe it would be good to trace the CPUs affected by the modification. It is possible to retrieve this information by going to /sys/kernel/debug/energy_model/xxx/cpus, but might be simpler when parsing a trace.
Regards, Pierre
On 3/14/23 11:33, Lukasz Luba wrote: > The Energy Model (EM) supports runtime modifications. Track the changes > in order to do post-processing analysis. Don't use arrays in the trace > event, since they are not properly supported by the tools. Instead use > simple "unroll" with emitting the trace event for each EM array entry > with proper ID information. The older debugging mechanism which was > the simple debugfs which dumping the EM content won't be sufficient for > the modifiable EM purpose. This trace event mechanism would address the > needs. > > Signed-off-by: Lukasz Luba <lukasz.luba@arm.com> > --- > include/trace/events/energy_model.h | 46 +++++++++++++++++++++++++++++ > kernel/power/energy_model.c | 3 ++ > 2 files changed, 49 insertions(+) > create mode 100644 include/trace/events/energy_model.h > > diff --git a/include/trace/events/energy_model.h b/include/trace/events/energy_model.h > new file mode 100644 > index 000000000000..f70babeb5dde > --- /dev/null > +++ b/include/trace/events/energy_model.h > @@ -0,0 +1,46 @@ > +/* SPDX-License-Identifier: GPL-2.0 */ > +#undef TRACE_SYSTEM > +#define TRACE_SYSTEM energy_model > + > +#if !defined(_TRACE_ENERGY_MODEL_H) || defined(TRACE_HEADER_MULTI_READ) > +#define _TRACE_ENERGY_MODEL_H > + > +#include <linux/tracepoint.h> > + > +TRACE_EVENT(em_perf_state, > + TP_PROTO(const char *dev_name, int nr_perf_states, int state, > + unsigned long ps_frequency, unsigned long ps_power, > + unsigned long ps_cost, unsigned long ps_flags), > + > + TP_ARGS(dev_name, nr_perf_states, state, ps_frequency, ps_power, ps_cost, > + ps_flags), > + > + TP_STRUCT__entry( > + __string(name, dev_name) > + __field(int, num_states) > + __field(int, state) > + __field(unsigned long, frequency) > + __field(unsigned long, power) > + __field(unsigned long, cost) > + __field(unsigned long, flags) > + ), > + > + TP_fast_assign( > + __assign_str(name, dev_name); > + __entry->num_states = nr_perf_states; > + __entry->state = state; > + __entry->frequency = ps_frequency; > + __entry->power = ps_power; > + __entry->cost = ps_cost; > + __entry->flags = ps_flags; > + ), > + > + TP_printk("dev_name=%s nr_perf_states=%d state=%d frequency=%lu power=%lu cost=%lu flags=%lu", > + __get_str(name), __entry->num_states, __entry->state, > + __entry->frequency, __entry->power, __entry->cost, > + __entry->flags) > +); > +#endif /* _TRACE_ENERGY_MODEL_H */ > + > +/* This part must be outside protection */ > +#include <trace/define_trace.h> > diff --git a/kernel/power/energy_model.c b/kernel/power/energy_model.c > index 937e98a71ed5..3b778743ba89 100644 > --- a/kernel/power/energy_model.c > +++ b/kernel/power/energy_model.c > @@ -17,6 +17,9 @@ > #include <linux/sched/topology.h> > #include <linux/slab.h> > > +#define CREATE_TRACE_POINTS > +#include <trace/events/energy_model.h> > + > /* > * Mutex serializing the registrations of performance domains and letting > * callbacks defined by drivers sleep.
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