diff options
Diffstat (limited to 'arch/mn10300/kernel/process.c')
-rw-r--r-- | arch/mn10300/kernel/process.c | 41 |
1 files changed, 37 insertions, 4 deletions
diff --git a/arch/mn10300/kernel/process.c b/arch/mn10300/kernel/process.c index 243e33c..b2e85ed 100644 --- a/arch/mn10300/kernel/process.c +++ b/arch/mn10300/kernel/process.c @@ -57,6 +57,7 @@ unsigned long thread_saved_pc(struct task_struct *tsk) void (*pm_power_off)(void); EXPORT_SYMBOL(pm_power_off); +#if !defined(CONFIG_SMP) || defined(CONFIG_HOTPLUG_CPU) /* * we use this if we don't have any better idle routine */ @@ -69,6 +70,35 @@ static void default_idle(void) local_irq_enable(); } +#else /* !CONFIG_SMP || CONFIG_HOTPLUG_CPU */ +/* + * On SMP it's slightly faster (but much more power-consuming!) + * to poll the ->work.need_resched flag instead of waiting for the + * cross-CPU IPI to arrive. Use this option with caution. + */ +static inline 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); + while (!need_resched()) + cpu_relax(); + clear_thread_flag(TIF_POLLING_NRFLAG); + } else { + set_need_resched(); + } +} +#endif /* !CONFIG_SMP || CONFIG_HOTPLUG_CPU */ + /* * the idle thread * - there's no useful work to be done, so just try to conserve power and have @@ -77,8 +107,6 @@ static void default_idle(void) */ void cpu_idle(void) { - int cpu = smp_processor_id(); - /* endless idle loop with no priority at all */ for (;;) { while (!need_resched()) { @@ -86,8 +114,13 @@ void cpu_idle(void) smp_rmb(); idle = pm_idle; - if (!idle) + if (!idle) { +#if defined(CONFIG_SMP) && !defined(CONFIG_HOTPLUG_CPU) + idle = poll_idle; +#else /* CONFIG_SMP && !CONFIG_HOTPLUG_CPU */ idle = default_idle; +#endif /* CONFIG_SMP && !CONFIG_HOTPLUG_CPU */ + } idle(); } @@ -233,7 +266,7 @@ int copy_thread(unsigned long clone_flags, } /* set up things up so the scheduler can start the new task */ - p->thread.__frame = c_kregs; + p->thread.frame = c_kregs; p->thread.a3 = (unsigned long) c_kregs; p->thread.sp = c_ksp; p->thread.pc = (unsigned long) ret_from_fork; |