commit
d306ebc28649b89877a22158fe0076f06cc46f60
(ACPI: Be in TS_POLLING state during mwait based C-state entry)
fixed an important power & performance issue where ACPI c2 and c3 C-states
were clearing TS_POLLING even when using MWAIT (ACPI_STATE_FFH).
That bug had been causing us to receive redundant scheduling interrups
when we had already been woken up by MONITOR/MWAIT.
Following up on that...
In the MWAIT case, we don't have to subsequently
check need_resched(), as that c heck was there
for the TS_POLLING-clearing case.
Note that not only does the cpuidle calling function
already check need_resched() before calling us, the
low-level entry into monitor/mwait calls it twice --
guaranteeing that a write to the trigger address
can not go un-noticed.
Also, in this case, we don't have to set TS_POLLING
when we wake, because we never cleared it.
Signed-off-by: Len Brown <len.brown@intel.com>
Acked-by: Venkatesh Pallipadi <venki@google.com>
return(acpi_idle_enter_c1(dev, state));
local_irq_disable();
return(acpi_idle_enter_c1(dev, state));
local_irq_disable();
if (cx->entry_method != ACPI_CSTATE_FFH) {
current_thread_info()->status &= ~TS_POLLING;
/*
if (cx->entry_method != ACPI_CSTATE_FFH) {
current_thread_info()->status &= ~TS_POLLING;
/*
* NEED_RESCHED:
*/
smp_mb();
* NEED_RESCHED:
*/
smp_mb();
- if (unlikely(need_resched())) {
- current_thread_info()->status |= TS_POLLING;
- local_irq_enable();
- return 0;
+ if (unlikely(need_resched())) {
+ current_thread_info()->status |= TS_POLLING;
+ local_irq_enable();
+ return 0;
+ }
sched_clock_idle_wakeup_event(sleep_ticks*PM_TIMER_TICK_NS);
local_irq_enable();
sched_clock_idle_wakeup_event(sleep_ticks*PM_TIMER_TICK_NS);
local_irq_enable();
- current_thread_info()->status |= TS_POLLING;
+ if (cx->entry_method != ACPI_CSTATE_FFH)
+ current_thread_info()->status |= TS_POLLING;
if (cx->entry_method != ACPI_CSTATE_FFH) {
current_thread_info()->status &= ~TS_POLLING;
/*
if (cx->entry_method != ACPI_CSTATE_FFH) {
current_thread_info()->status &= ~TS_POLLING;
/*
* NEED_RESCHED:
*/
smp_mb();
* NEED_RESCHED:
*/
smp_mb();
- if (unlikely(need_resched())) {
- current_thread_info()->status |= TS_POLLING;
- local_irq_enable();
- return 0;
+ if (unlikely(need_resched())) {
+ current_thread_info()->status |= TS_POLLING;
+ local_irq_enable();
+ return 0;
+ }
}
acpi_unlazy_tlb(smp_processor_id());
}
acpi_unlazy_tlb(smp_processor_id());
sched_clock_idle_wakeup_event(sleep_ticks*PM_TIMER_TICK_NS);
local_irq_enable();
sched_clock_idle_wakeup_event(sleep_ticks*PM_TIMER_TICK_NS);
local_irq_enable();
- current_thread_info()->status |= TS_POLLING;
+ if (cx->entry_method != ACPI_CSTATE_FFH)
+ current_thread_info()->status |= TS_POLLING;