On Tue, Jun 1, 2010 at 8:04 PM, <yakui.zhao@xxxxxxxxx> wrote: > From: Zhao Yakui <yakui.zhao@xxxxxxxxx> > > The C-state idle time is not calculated correctly, which will return the wrong > residency time in C-state. It will have the following effects: > 1. The system can't choose the deeper C-state when it is idle next time. > Of course the system power is increased. E.g. On one server machine about 40W > idle power is increased. > 2. The powertop shows that it will stay in C0 running state about 95% time > although the system is idle at most time. This was a bug from my recent patch here :-( http://marc.info/?l=linux-acpi&m=127198016715509&w=2 Thanks for catching this.. Acked-by: Venkatesh Pallipadi <venki@xxxxxxxxxx> > > Signed-off-by: Zhao Yakui <yakui.zhao@xxxxxxxxx> > Reported-by: Yu Zhidong <zhidong.yu@xxxxxxxxx> > Tested-by: Yu Zhidong <zhidong.yu@xxxxxxxxx> > CC: Venkatesh Pallipadi <venki@xxxxxxxxxx> > --- > drivers/acpi/processor_idle.c | 2 +- > 1 files changed, 1 insertions(+), 1 deletions(-) > > diff --git a/drivers/acpi/processor_idle.c b/drivers/acpi/processor_idle.c > index 2e8c27d..6b38a6b 100644 > --- a/drivers/acpi/processor_idle.c > +++ b/drivers/acpi/processor_idle.c > @@ -1022,7 +1022,7 @@ static int acpi_idle_enter_bm(struct cpuidle_device *dev, > spin_unlock(&c3_lock); > } > kt2 = ktime_get_real(); > - idle_time_ns = ktime_to_us(ktime_sub(kt2, kt1)); > + idle_time_ns = ktime_to_ns(ktime_sub(kt2, kt1)); > idle_time = idle_time_ns; > do_div(idle_time, NSEC_PER_USEC); > > -- > 1.5.4.5 > > -- To unsubscribe from this list: send the line "unsubscribe linux-acpi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
