On Friday, May 18, 2012, Sameer Nanda wrote:
> Added event tracing for device_resume. This helps quickly pinpoint which
> devices take a long time to resume.
There is some code already for that in the PM core. You have to boot the
kernel with initcall_debug in the command line to activate it.
Thanks,
Rafael
> Signed-off-by: Sameer Nanda <snanda@xxxxxxxxxxxx>
> ---
> Documentation/trace/events-power.txt | 20 +++++++++++
> drivers/base/power/main.c | 10 ++++++
> include/trace/events/power.h | 59 ++++++++++++++++++++++++++++++++++
> 3 files changed, 89 insertions(+), 0 deletions(-)
>
> diff --git a/Documentation/trace/events-power.txt b/Documentation/trace/events-power.txt
> index cf794af..dbfb7f0 100644
> --- a/Documentation/trace/events-power.txt
> +++ b/Documentation/trace/events-power.txt
> @@ -88,3 +88,23 @@ power_domain_target "%s state=%lu cpu_id=%lu"
> The first parameter gives the power domain name (e.g. "mpu_pwrdm").
> The second parameter is the power domain target state.
>
> +4. Device resume events
> +=======================
> +The device resume events are used for measuring the time taken to resume
> +devices.
> +
> +device_resume_in "device=%s driver=%s"
> +device_resume_waited "device=%s driver=%s time_delta=%lld"
> +device_resume_out "device=%s driver=%s time_delta=%lld"
> +
> +The first parameter is the device that is being resumed.
> +
> +The second parameter is the driver associated with the device being resumed.
> +
> +The third parameter in device_resume_waited is the time delta from the entry
> +point of device_resume to the wait completion of parent device being resumed.
> +The unit for time_delta is us.
> +
> +The third parameter in device_resume_out is the time delta from the wait
> +completion of parent device being resumed to device_resume being completed.
> +The unit for time_delta is us.
> diff --git a/drivers/base/power/main.c b/drivers/base/power/main.c
> index b462c0e..3ed01cd 100644
> --- a/drivers/base/power/main.c
> +++ b/drivers/base/power/main.c
> @@ -28,6 +28,7 @@
> #include <linux/sched.h>
> #include <linux/async.h>
> #include <linux/suspend.h>
> +#include <trace/events/power.h>
>
> #include "../base.h"
> #include "power.h"
> @@ -565,11 +566,19 @@ static int device_resume(struct device *dev, pm_message_t state, bool async)
> char *info = NULL;
> int error = 0;
> bool put = false;
> + s64 in_time = ktime_to_us(ktime_get());
> + s64 wait_done_time;
> +
> + trace_device_resume_in(dev);
>
> TRACE_DEVICE(dev);
> TRACE_RESUME(0);
>
> dpm_wait(dev->parent, async);
> +
> + wait_done_time = ktime_to_us(ktime_get());
> + trace_device_resume_waited(dev, wait_done_time - in_time);
> +
> device_lock(dev);
>
> /*
> @@ -638,6 +647,7 @@ static int device_resume(struct device *dev, pm_message_t state, bool async)
> if (put)
> pm_runtime_put_sync(dev);
>
> + trace_device_resume_out(dev, ktime_to_us(ktime_get()) - wait_done_time);
> return error;
> }
>
> diff --git a/include/trace/events/power.h b/include/trace/events/power.h
> index cae9a94..9601419 100644
> --- a/include/trace/events/power.h
> +++ b/include/trace/events/power.h
> @@ -4,6 +4,7 @@
> #if !defined(_TRACE_POWER_H) || defined(TRACE_HEADER_MULTI_READ)
> #define _TRACE_POWER_H
>
> +#include <linux/device.h>
> #include <linux/ktime.h>
> #include <linux/tracepoint.h>
>
> @@ -48,6 +49,64 @@ DEFINE_EVENT(cpu, cpu_frequency,
> TP_ARGS(frequency, cpu_id)
> );
>
> +#define get_driver_name(dev) dev->driver && dev->driver->name ? \
> + dev->driver->name : ""
> +
> +TRACE_EVENT(device_resume_in,
> +
> + TP_PROTO(struct device *dev),
> +
> + TP_ARGS(dev),
> +
> + TP_STRUCT__entry(
> + __string( device_name, dev_name(dev) )
> + __string( driver_name, get_driver_name(dev) )
> + ),
> +
> + TP_fast_assign(
> + __assign_str(device_name, dev_name(dev));
> + __assign_str(driver_name, get_driver_name(dev));
> + ),
> +
> + TP_printk("device=%s driver=%s", __get_str(device_name), __get_str(driver_name))
> +);
> +
> +DECLARE_EVENT_CLASS(device_resume_internal,
> +
> + TP_PROTO(struct device *dev, s64 time_delta),
> +
> + TP_ARGS(dev, time_delta),
> +
> + TP_STRUCT__entry(
> + __field( s64, time_delta )
> + __string( device_name, dev_name(dev) )
> + __string( driver_name, get_driver_name(dev) )
> + ),
> +
> + TP_fast_assign(
> + __entry->time_delta = time_delta;
> + __assign_str(device_name, dev_name(dev));
> + __assign_str(driver_name, get_driver_name(dev));
> + ),
> +
> + TP_printk("device=%s driver=%s time_delta=%lld", __get_str(device_name),
> + __get_str(driver_name), __entry->time_delta)
> +);
> +
> +DEFINE_EVENT(device_resume_internal, device_resume_waited,
> +
> + TP_PROTO(struct device *dev, s64 time_delta),
> +
> + TP_ARGS(dev, time_delta)
> +);
> +
> +DEFINE_EVENT(device_resume_internal, device_resume_out,
> +
> + TP_PROTO(struct device *dev, s64 time_delta),
> +
> + TP_ARGS(dev, time_delta)
> +);
> +
> TRACE_EVENT(machine_suspend,
>
> TP_PROTO(unsigned int state),
>
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