x86: idle wakeup event in the HLT loop
do a proper idle-wakeup event on HLT as well - some CPUs stop the TSC
in HLT too, not just when going through the ACPI methods.
(the ACPI idle code already does this.)
[ update the 64-bit side too, as noticed by Jiri Slaby. ]
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
diff --git a/arch/x86/kernel/process_64.c b/arch/x86/kernel/process_64.c
index c2db7ef..40fed47 100644
--- a/arch/x86/kernel/process_64.c
+++ b/arch/x86/kernel/process_64.c
@@ -116,9 +116,16 @@
smp_mb();
local_irq_disable();
if (!need_resched()) {
- /* Enables interrupts one instruction before HLT.
- x86 special cases this so there is no race. */
- safe_halt();
+ ktime_t t0, t1;
+ u64 t0n, t1n;
+
+ t0 = ktime_get();
+ t0n = ktime_to_ns(t0);
+ safe_halt(); /* enables interrupts racelessly */
+ local_irq_disable();
+ t1 = ktime_get();
+ t1n = ktime_to_ns(t1);
+ sched_clock_idle_wakeup_event(t1n - t0n);
} else
local_irq_enable();
current_thread_info()->status |= TS_POLLING;