| Message ID | 20240221194754.986300-1-vilasbhat@google.com |
|---|---|
| State | Accepted |
| Commit | 015abee404760249a5c968b9ce29216b94b8ced1 |
| Headers | show |
| Series | [v2] PM: runtime: add tracepoint for runtime_status changes | expand |
On Wed, Feb 21, 2024 at 8:49 PM Vilas Bhat <vilasbhat@google.com> wrote: > > Existing runtime PM ftrace events (`rpm_suspend`, `rpm_resume`, > `rpm_return_int`) offer limited visibility into the exact timing of device > runtime power state transitions, particularly when asynchronous operations > are involved. When the `rpm_suspend` or `rpm_resume` functions are invoked > with the `RPM_ASYNC` flag, a return value of 0 i.e., success merely > indicates that the device power state request has been queued, not that > the device has yet transitioned. > > A new ftrace event, `rpm_status`, is introduced. This event directly logs > the `power.runtime_status` value of a device whenever it changes providing > granular tracking of runtime power state transitions regardless of > synchronous or asynchronous `rpm_suspend` / `rpm_resume` usage. > > Signed-off-by: Vilas Bhat <vilasbhat@google.com> > --- > V1 -> V2: Modified enum value definition as per reviewer comments. > --- > drivers/base/power/runtime.c | 1 + > include/trace/events/rpm.h | 42 ++++++++++++++++++++++++++++++++++++ > 2 files changed, 43 insertions(+) > > diff --git a/drivers/base/power/runtime.c b/drivers/base/power/runtime.c > index 05793c9fbb84..d10354847878 100644 > --- a/drivers/base/power/runtime.c > +++ b/drivers/base/power/runtime.c > @@ -94,6 +94,7 @@ static void update_pm_runtime_accounting(struct device *dev) > static void __update_runtime_status(struct device *dev, enum rpm_status status) > { > update_pm_runtime_accounting(dev); > + trace_rpm_status(dev, status); > dev->power.runtime_status = status; > } > > diff --git a/include/trace/events/rpm.h b/include/trace/events/rpm.h > index 3c716214dab1..bd120e23ce12 100644 > --- a/include/trace/events/rpm.h > +++ b/include/trace/events/rpm.h > @@ -101,6 +101,48 @@ TRACE_EVENT(rpm_return_int, > __entry->ret) > ); > > +#define RPM_STATUS_STRINGS \ > + EM(RPM_INVALID, "RPM_INVALID") \ > + EM(RPM_ACTIVE, "RPM_ACTIVE") \ > + EM(RPM_RESUMING, "RPM_RESUMING") \ > + EM(RPM_SUSPENDED, "RPM_SUSPENDED") \ > + EMe(RPM_SUSPENDING, "RPM_SUSPENDING") > + > +/* Enums require being exported to userspace, for user tool parsing. */ > +#undef EM > +#undef EMe > +#define EM(a, b) TRACE_DEFINE_ENUM(a); > +#define EMe(a, b) TRACE_DEFINE_ENUM(a); > + > +RPM_STATUS_STRINGS > + > +/* > + * Now redefine the EM() and EMe() macros to map the enums to the strings that > + * will be printed in the output. > + */ > +#undef EM > +#undef EMe > +#define EM(a, b) { a, b }, > +#define EMe(a, b) { a, b } > + > +TRACE_EVENT(rpm_status, > + TP_PROTO(struct device *dev, enum rpm_status status), > + TP_ARGS(dev, status), > + > + TP_STRUCT__entry( > + __string(name, dev_name(dev)) > + __field(int, status) > + ), > + > + TP_fast_assign( > + __assign_str(name, dev_name(dev)); > + __entry->status = status; > + ), > + > + TP_printk("%s status=%s", __get_str(name), > + __print_symbolic(__entry->status, RPM_STATUS_STRINGS)) > +); > + > #endif /* _TRACE_RUNTIME_POWER_H */ > > /* This part must be outside protection */ > -- Applied as 6.9 material, thanks!
diff --git a/drivers/base/power/runtime.c b/drivers/base/power/runtime.c index 05793c9fbb84..d10354847878 100644 --- a/drivers/base/power/runtime.c +++ b/drivers/base/power/runtime.c @@ -94,6 +94,7 @@ static void update_pm_runtime_accounting(struct device *dev) static void __update_runtime_status(struct device *dev, enum rpm_status status) { update_pm_runtime_accounting(dev); + trace_rpm_status(dev, status); dev->power.runtime_status = status; } diff --git a/include/trace/events/rpm.h b/include/trace/events/rpm.h index 3c716214dab1..bd120e23ce12 100644 --- a/include/trace/events/rpm.h +++ b/include/trace/events/rpm.h @@ -101,6 +101,48 @@ TRACE_EVENT(rpm_return_int, __entry->ret) ); +#define RPM_STATUS_STRINGS \ + EM(RPM_INVALID, "RPM_INVALID") \ + EM(RPM_ACTIVE, "RPM_ACTIVE") \ + EM(RPM_RESUMING, "RPM_RESUMING") \ + EM(RPM_SUSPENDED, "RPM_SUSPENDED") \ + EMe(RPM_SUSPENDING, "RPM_SUSPENDING") + +/* Enums require being exported to userspace, for user tool parsing. */ +#undef EM +#undef EMe +#define EM(a, b) TRACE_DEFINE_ENUM(a); +#define EMe(a, b) TRACE_DEFINE_ENUM(a); + +RPM_STATUS_STRINGS + +/* + * Now redefine the EM() and EMe() macros to map the enums to the strings that + * will be printed in the output. + */ +#undef EM +#undef EMe +#define EM(a, b) { a, b }, +#define EMe(a, b) { a, b } + +TRACE_EVENT(rpm_status, + TP_PROTO(struct device *dev, enum rpm_status status), + TP_ARGS(dev, status), + + TP_STRUCT__entry( + __string(name, dev_name(dev)) + __field(int, status) + ), + + TP_fast_assign( + __assign_str(name, dev_name(dev)); + __entry->status = status; + ), + + TP_printk("%s status=%s", __get_str(name), + __print_symbolic(__entry->status, RPM_STATUS_STRINGS)) +); + #endif /* _TRACE_RUNTIME_POWER_H */ /* This part must be outside protection */
Existing runtime PM ftrace events (`rpm_suspend`, `rpm_resume`, `rpm_return_int`) offer limited visibility into the exact timing of device runtime power state transitions, particularly when asynchronous operations are involved. When the `rpm_suspend` or `rpm_resume` functions are invoked with the `RPM_ASYNC` flag, a return value of 0 i.e., success merely indicates that the device power state request has been queued, not that the device has yet transitioned. A new ftrace event, `rpm_status`, is introduced. This event directly logs the `power.runtime_status` value of a device whenever it changes providing granular tracking of runtime power state transitions regardless of synchronous or asynchronous `rpm_suspend` / `rpm_resume` usage. Signed-off-by: Vilas Bhat <vilasbhat@google.com> --- V1 -> V2: Modified enum value definition as per reviewer comments. --- drivers/base/power/runtime.c | 1 + include/trace/events/rpm.h | 42 ++++++++++++++++++++++++++++++++++++ 2 files changed, 43 insertions(+)