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-rw-r--r--arch/x86_64/kernel/process.c19
-rw-r--r--include/asm-x86_64/processor.h8
2 files changed, 25 insertions, 2 deletions
diff --git a/arch/x86_64/kernel/process.c b/arch/x86_64/kernel/process.c
index 0b7b4ca..a418ee4 100644
--- a/arch/x86_64/kernel/process.c
+++ b/arch/x86_64/kernel/process.c
@@ -127,6 +127,7 @@ static void default_idle(void)
*/
static void poll_idle (void)
{
+ local_irq_enable();
cpu_relax();
}
@@ -208,6 +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
@@ -245,8 +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();
- 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)
diff --git a/include/asm-x86_64/processor.h b/include/asm-x86_64/processor.h
index cef17e0..76552d7 100644
--- a/include/asm-x86_64/processor.h
+++ b/include/asm-x86_64/processor.h
@@ -475,6 +475,14 @@ static inline void __mwait(unsigned long eax, unsigned long ecx)
: :"a" (eax), "c" (ecx));
}
+static inline void __sti_mwait(unsigned long eax, unsigned long ecx)
+{
+ /* "mwait %eax,%ecx;" */
+ asm volatile(
+ "sti; .byte 0x0f,0x01,0xc9;"
+ : :"a" (eax), "c" (ecx));
+}
+
extern void mwait_idle_with_hints(unsigned long eax, unsigned long ecx);
#define stack_current() \
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