On Wed, 18 Sep 2019 12:15:37 -0700 Matthias Kaehlcke <[email protected]> wrote:
> Add a tracepoint for frequency changes of devfreq devices and > use it. > > Signed-off-by: Matthias Kaehlcke <[email protected]> > --- > drivers/devfreq/devfreq.c | 3 +++ > include/trace/events/devfreq.h | 18 ++++++++++++++++++ > 2 files changed, 21 insertions(+) > > diff --git a/drivers/devfreq/devfreq.c b/drivers/devfreq/devfreq.c > index ab22bf8a12d6..32de1f6ac776 100644 > --- a/drivers/devfreq/devfreq.c > +++ b/drivers/devfreq/devfreq.c > @@ -317,6 +317,9 @@ static int devfreq_set_target(struct devfreq *devfreq, > unsigned long new_freq, > > devfreq->previous_freq = new_freq; > > + if (new_freq != cur_freq) I would make this: if (trace_devfreq_frequency_enabled() && new_freq != cur_freq) Because this would place the second check into the "nop" portion of the code, keeping the test from being performed if the devfreq_frequency trace point is not enabled. Slight micro optimization, but still enough to add it. -- Steve > + trace_devfreq_frequency(devfreq, new_freq); > + > if (devfreq->suspend_freq) > devfreq->resume_freq = cur_freq; > > diff --git a/include/trace/events/devfreq.h b/include/trace/events/devfreq.h > index cf5b8772175d..a62d32fe3c33 100644 > --- a/include/trace/events/devfreq.h > +++ b/include/trace/events/devfreq.h > @@ -8,6 +8,24 @@ > #include <linux/devfreq.h> > #include <linux/tracepoint.h> > > +TRACE_EVENT(devfreq_frequency, > + TP_PROTO(struct devfreq *devfreq, unsigned long freq), > + > + TP_ARGS(devfreq, freq), > + > + TP_STRUCT__entry( > + __string(dev_name, dev_name(&devfreq->dev)) > + __field(unsigned long, freq) > + ), > + > + TP_fast_assign( > + __assign_str(dev_name, dev_name(&devfreq->dev)); > + __entry->freq = freq; > + ), > + > + TP_printk("dev_name=%s freq=%lu", __get_str(dev_name), __entry->freq) > +); > + > TRACE_EVENT(devfreq_monitor, > TP_PROTO(struct devfreq *devfreq), >
