Hi Rafael, On Fri, 21 Dec 2018 at 09:58, Rafael J. Wysocki <rafael@xxxxxxxxxx> wrote: > > On Thu, Dec 20, 2018 at 11:03 PM Ulf Hansson <ulf.hansson@xxxxxxxxxx> wrote: > > > > On Thu, 20 Dec 2018 at 15:17, Vincent Guittot > > <vincent.guittot@xxxxxxxxxx> wrote: > > > > > > From: Thara Gopinath <thara.gopinath@xxxxxxxxxx> > > > > > > This patch replaces jiffies based accounting for runtime_active_time > > > and runtime_suspended_time with ktime base accounting. This makes the > > > runtime debug counters inline with genpd and other pm subsytems which > > > uses ktime based accounting. > > > > > > Signed-off-by: Thara Gopinath <thara.gopinath@xxxxxxxxxx> > > > [move from ktime to raw nsec] > > > Signed-off-by: Vincent Guittot <vincent.guittot@xxxxxxxxxx> > > > --- > > > drivers/base/power/runtime.c | 17 +++++++++-------- > > > drivers/base/power/sysfs.c | 11 ++++++++--- > > > include/linux/pm.h | 6 +++--- > > > 3 files changed, 20 insertions(+), 14 deletions(-) > > > > > > diff --git a/drivers/base/power/runtime.c b/drivers/base/power/runtime.c > > > index e695544..f700524 100644 > > > --- a/drivers/base/power/runtime.c > > > +++ b/drivers/base/power/runtime.c > > > @@ -64,8 +64,8 @@ static int rpm_suspend(struct device *dev, int rpmflags); > > > */ > > > void update_pm_runtime_accounting(struct device *dev) > > > { > > > - unsigned long now = jiffies; > > > - unsigned long delta; > > > + u64 now = ktime_to_ns(ktime_get()); > > > + u64 delta; > > > > > > delta = now - dev->power.accounting_timestamp; > > > > > > @@ -75,9 +75,9 @@ void update_pm_runtime_accounting(struct device *dev) > > > return; > > > > > > if (dev->power.runtime_status == RPM_SUSPENDED) > > > - dev->power.suspended_jiffies += delta; > > > + dev->power.suspended_time += delta; > > > else > > > - dev->power.active_jiffies += delta; > > > + dev->power.active_time += delta; > > > } > > > > > > static void __update_runtime_status(struct device *dev, enum rpm_status status) > > > @@ -88,17 +88,18 @@ static void __update_runtime_status(struct device *dev, enum rpm_status status) > > > > > > u64 pm_runtime_suspended_time(struct device *dev) > > > { > > > - unsigned long flags, time; > > > + u64 time; > > > + unsigned long flags; > > > > > > spin_lock_irqsave(&dev->power.lock, flags); > > > > > > update_pm_runtime_accounting(dev); > > > > > > - time = dev->power.suspended_jiffies; > > > + time = dev->power.suspended_time; > > > > > > spin_unlock_irqrestore(&dev->power.lock, flags); > > > > > > - return jiffies_to_nsecs(time); > > > + return time; > > > } > > > EXPORT_SYMBOL_GPL(pm_runtime_suspended_time); > > > > > > @@ -1503,7 +1504,7 @@ void pm_runtime_init(struct device *dev) > > > dev->power.request_pending = false; > > > dev->power.request = RPM_REQ_NONE; > > > dev->power.deferred_resume = false; > > > - dev->power.accounting_timestamp = jiffies; > > > + dev->power.accounting_timestamp = ktime_to_ns(ktime_get()); > > > > This change worries me a bit, but it may not be a problem in practice. > > > > pm_runtime_init() is called when devices get initialized, via > > device_initialize(). If timekeeping has not been initialized prior a > > call to ktime_get() is done, it will fail and causing a NULL pointer > > deference or something along those lines. > > > > In other words, do we know that device_initialize() is always called > > after timekeeping has been initialized during boot? > > We do. > > timekeeping_init() is called early in start_kernel() which is way > before driver_init() (and that's when devices can start to be > initialized) called from rest_init() via kernel_init_freeable() and > do_basic_setup(). Thanks for the confirmation. I'm going to add your answer in the commit message so we will have the answer next time someone will wonder _______________________________________________ dri-devel mailing list dri-devel@xxxxxxxxxxxxxxxxxxxxx https://lists.freedesktop.org/mailman/listinfo/dri-devel