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Diffstat (limited to 'arch/i386/kernel/process.c')
-rw-r--r--arch/i386/kernel/process.c64
1 files changed, 28 insertions, 36 deletions
diff --git a/arch/i386/kernel/process.c b/arch/i386/kernel/process.c
index 5296e284ea3..1cb261f225d 100644
--- a/arch/i386/kernel/process.c
+++ b/arch/i386/kernel/process.c
@@ -99,14 +99,22 @@ EXPORT_SYMBOL(enable_hlt);
*/
void default_idle(void)
{
+ local_irq_enable();
+
if (!hlt_counter && boot_cpu_data.hlt_works_ok) {
- local_irq_disable();
- if (!need_resched())
- safe_halt();
- else
- local_irq_enable();
+ clear_thread_flag(TIF_POLLING_NRFLAG);
+ smp_mb__after_clear_bit();
+ while (!need_resched()) {
+ local_irq_disable();
+ if (!need_resched())
+ safe_halt();
+ else
+ local_irq_enable();
+ }
+ set_thread_flag(TIF_POLLING_NRFLAG);
} else {
- cpu_relax();
+ while (!need_resched())
+ cpu_relax();
}
}
#ifdef CONFIG_APM_MODULE
@@ -120,29 +128,14 @@ EXPORT_SYMBOL(default_idle);
*/
static void poll_idle (void)
{
- int oldval;
-
local_irq_enable();
- /*
- * Deal with another CPU just having chosen a thread to
- * run here:
- */
- oldval = test_and_clear_thread_flag(TIF_NEED_RESCHED);
-
- if (!oldval) {
- set_thread_flag(TIF_POLLING_NRFLAG);
- asm volatile(
- "2:"
- "testl %0, %1;"
- "rep; nop;"
- "je 2b;"
- : : "i"(_TIF_NEED_RESCHED), "m" (current_thread_info()->flags));
-
- clear_thread_flag(TIF_POLLING_NRFLAG);
- } else {
- set_need_resched();
- }
+ asm volatile(
+ "2:"
+ "testl %0, %1;"
+ "rep; nop;"
+ "je 2b;"
+ : : "i"(_TIF_NEED_RESCHED), "m" (current_thread_info()->flags));
}
#ifdef CONFIG_HOTPLUG_CPU
@@ -181,6 +174,8 @@ void cpu_idle(void)
{
int cpu = smp_processor_id();
+ set_thread_flag(TIF_POLLING_NRFLAG);
+
/* endless idle loop with no priority at all */
while (1) {
while (!need_resched()) {
@@ -246,15 +241,12 @@ static void mwait_idle(void)
{
local_irq_enable();
- if (!need_resched()) {
- set_thread_flag(TIF_POLLING_NRFLAG);
- do {
- __monitor((void *)&current_thread_info()->flags, 0, 0);
- if (need_resched())
- break;
- __mwait(0, 0);
- } while (!need_resched());
- clear_thread_flag(TIF_POLLING_NRFLAG);
+ while (!need_resched()) {
+ __monitor((void *)&current_thread_info()->flags, 0, 0);
+ smp_mb();
+ if (need_resched())
+ break;
+ __mwait(0, 0);
}
}