On Fri, Sep 20, 2019 at 10:15:57AM +0900, Chanwoo Choi wrote: > Hi, sorry for the delayed response, you message got buried in my mailbox.
> On 19. 9. 20. 오전 2:44, Matthias Kaehlcke wrote: > > Add a tracepoint for frequency changes of devfreq devices and > > use it. > > > > Signed-off-by: Matthias Kaehlcke <m...@chromium.org> > > --- > > (sending v2 without much delay wrt v1, since the change in devfreq > > probably isn't controversial, and I'll be offline a few days) > > > > Changes in v2: > > - included trace_devfreq_frequency_enabled() in the condition > > to avoid unnecessary evaluation when the trace point is > > disabled > > --- > > 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..e9f04dcafb01 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 (trace_devfreq_frequency_enabled() && new_freq != cur_freq) > > + trace_devfreq_frequency(devfreq, new_freq); > > You can change as following without 'new_freq' variable > because devfreq->previous_freq is the new frequency. > trace_devfreq_frequency(devfreq); In general that sounds good. devfreq essentially uses df->previous_freq as df->cur_freq, I think most code using it would be clearer if we renamed it accordingly. I'll send a separate patch for this. > > + > > 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), > > 'unsigned long freq' parameter is not necessary. > > > + > > + 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; > > Initialize the new frequency with 'devfreq->previous_freq' as following: > > __entry->freq = devfreq->previous_freq; > > > + ), > > + > > + TP_printk("dev_name=%s freq=%lu", __get_str(dev_name), __entry->freq) > > +); > > + > > TRACE_EVENT(devfreq_monitor, > > TP_PROTO(struct devfreq *devfreq), > > > > > > > -- > Best Regards, > Chanwoo Choi > Samsung Electronics