summaryrefslogtreecommitdiffstats
path: root/arch/x86_64/kernel/process.c
diff options
context:
space:
mode:
Diffstat (limited to 'arch/x86_64/kernel/process.c')
-rw-r--r--arch/x86_64/kernel/process.c45
1 files changed, 24 insertions, 21 deletions
diff --git a/arch/x86_64/kernel/process.c b/arch/x86_64/kernel/process.c
index 7451a4c..a418ee4 100644
--- a/arch/x86_64/kernel/process.c
+++ b/arch/x86_64/kernel/process.c
@@ -108,17 +108,15 @@ void exit_idle(void)
*/
static void default_idle(void)
{
- local_irq_enable();
-
current_thread_info()->status &= ~TS_POLLING;
smp_mb__after_clear_bit();
- while (!need_resched()) {
- local_irq_disable();
- if (!need_resched())
- safe_halt();
- else
- local_irq_enable();
- }
+ local_irq_disable();
+ if (!need_resched()) {
+ /* Enables interrupts one instruction before HLT.
+ x86 special cases this so there is no race. */
+ safe_halt();
+ } else
+ local_irq_enable();
current_thread_info()->status |= TS_POLLING;
}
@@ -130,15 +128,7 @@ static void default_idle(void)
static void poll_idle (void)
{
local_irq_enable();
-
- asm volatile(
- "2:"
- "testl %0,%1;"
- "rep; nop;"
- "je 2b;"
- : :
- "i" (_TIF_NEED_RESCHED),
- "m" (current_thread_info()->flags));
+ cpu_relax();
}
void cpu_idle_wait(void)
@@ -219,6 +209,12 @@ void cpu_idle (void)
idle = default_idle;
if (cpu_is_offline(smp_processor_id()))
play_dead();
+ /*
+ * Idle routines should keep interrupts disabled
+ * from here on, until they go to idle.
+ * Otherwise, idle callbacks can misfire.
+ */
+ local_irq_disable();
enter_idle();
idle();
/* In many cases the interrupt that ended idle
@@ -256,9 +252,16 @@ void mwait_idle_with_hints(unsigned long eax, unsigned long ecx)
/* Default MONITOR/MWAIT with no hints, used for default C1 state */
static void mwait_idle(void)
{
- local_irq_enable();
- while (!need_resched())
- mwait_idle_with_hints(0,0);
+ if (!need_resched()) {
+ __monitor((void *)&current_thread_info()->flags, 0, 0);
+ smp_mb();
+ if (!need_resched())
+ __sti_mwait(0, 0);
+ else
+ local_irq_enable();
+ } else {
+ local_irq_enable();
+ }
}
void __cpuinit select_idle_routine(const struct cpuinfo_x86 *c)
OpenPOWER on IntegriCloud