On Tue, 21 Apr 2009, Len Brown wrote: > From: Len Brown <len.brown@xxxxxxxxx> > > The c2 and c3 idle handlers check tsc_halts_in_c() > after every time they return from idle. Um, when?:-) > > Move this check to init-time to remove the unnecessary > run-time overhead, and also to have the check complete before > the first entry into the idle handler. > > ff69f2bba67bd45514923aaedbf40fe351787c59 > (acpi: fix of pmtimer overflow that make Cx states time incorrect) > replaced the hard-coded use of the PM-timer inside idle, > with ktime_get_readl(), which possibly uses the TSC -- > so it is now especially prudent to detect a broken TSC > before entering idle. > > http://bugzilla.kernel.org/show_bug.cgi?id=13087 > > Signed-off-by: Len Brown <len.brown@xxxxxxxxx> Acked-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx> > --- > drivers/acpi/processor_idle.c | 15 +++++---------- > 1 files changed, 5 insertions(+), 10 deletions(-) > > diff --git a/drivers/acpi/processor_idle.c b/drivers/acpi/processor_idle.c > index 6fe1214..9d1f01e 100644 > --- a/drivers/acpi/processor_idle.c > +++ b/drivers/acpi/processor_idle.c > @@ -581,6 +581,11 @@ static int acpi_processor_power_verify(struct acpi_processor *pr) > for (i = 1; i < ACPI_PROCESSOR_MAX_POWER; i++) { > struct acpi_processor_cx *cx = &pr->power.states[i]; > > +#if defined (CONFIG_GENERIC_TIME) && defined (CONFIG_X86) > + /* TSC could halt in idle, so notify users */ > + if (tsc_halts_in_c(cx->type)) > + mark_tsc_unstable("TSC halts in idle");; > +#endif > switch (cx->type) { > case ACPI_STATE_C1: > cx->valid = 1; > @@ -871,11 +876,6 @@ static int acpi_idle_enter_simple(struct cpuidle_device *dev, > kt2 = ktime_get_real(); > idle_time = ktime_to_us(ktime_sub(kt2, kt1)); > > -#if defined (CONFIG_GENERIC_TIME) && defined (CONFIG_X86) > - /* TSC could halt in idle, so notify users */ > - if (tsc_halts_in_c(cx->type)) > - mark_tsc_unstable("TSC halts in idle");; > -#endif > sleep_ticks = us_to_pm_timer_ticks(idle_time); > > /* Tell the scheduler how much we idled: */ > @@ -989,11 +989,6 @@ static int acpi_idle_enter_bm(struct cpuidle_device *dev, > spin_unlock(&c3_lock); > } > > -#if defined (CONFIG_GENERIC_TIME) && defined (CONFIG_X86) > - /* TSC could halt in idle, so notify users */ > - if (tsc_halts_in_c(ACPI_STATE_C3)) > - mark_tsc_unstable("TSC halts in idle"); > -#endif > sleep_ticks = us_to_pm_timer_ticks(idle_time); > /* Tell the scheduler how much we idled: */ > sched_clock_idle_wakeup_event(sleep_ticks*PM_TIMER_TICK_NS); > -- > 1.6.3.rc1.18.g66996 > -- 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
