diff options
| -rw-r--r-- | arch/i386/kernel/process.c | 30 | ||||
| -rw-r--r-- | arch/x86_64/kernel/process.c | 30 |
2 files changed, 18 insertions, 42 deletions
diff --git a/arch/i386/kernel/process.c b/arch/i386/kernel/process.c index 8749b10d380..8f42659ef9d 100644 --- a/arch/i386/kernel/process.c +++ b/arch/i386/kernel/process.c @@ -100,22 +100,18 @@ EXPORT_SYMBOL(enable_hlt); */ void default_idle(void) { - local_irq_enable(); - if (!hlt_counter && boot_cpu_data.hlt_works_ok) { 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()) + safe_halt(); /* enables interrupts racelessly */ + else + local_irq_enable(); current_thread_info()->status |= TS_POLLING; } else { - while (!need_resched()) - cpu_relax(); + /* loop is done by the caller */ + cpu_relax(); } } #ifdef CONFIG_APM_MODULE @@ -129,14 +125,7 @@ EXPORT_SYMBOL(default_idle); */ 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(); } #ifdef CONFIG_HOTPLUG_CPU @@ -257,8 +246,7 @@ void mwait_idle_with_hints(unsigned long eax, unsigned long ecx) static void mwait_idle(void) { local_irq_enable(); - while (!need_resched()) - mwait_idle_with_hints(0, 0); + mwait_idle_with_hints(0, 0); } void __devinit select_idle_routine(const struct cpuinfo_x86 *c) diff --git a/arch/x86_64/kernel/process.c b/arch/x86_64/kernel/process.c index 7451a4c43c1..0b7b4caa4f7 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; } @@ -129,16 +127,7 @@ 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) @@ -257,8 +246,7 @@ void mwait_idle_with_hints(unsigned long eax, unsigned long ecx) static void mwait_idle(void) { local_irq_enable(); - while (!need_resched()) - mwait_idle_with_hints(0,0); + mwait_idle_with_hints(0,0); } void __cpuinit select_idle_routine(const struct cpuinfo_x86 *c) |