diff options
Diffstat (limited to 'kernel/sched/idle.c')
| -rw-r--r-- | kernel/sched/idle.c | 19 |
1 files changed, 18 insertions, 1 deletions
diff --git a/kernel/sched/idle.c b/kernel/sched/idle.c index c47fce75e666..94b2d7b88a27 100644 --- a/kernel/sched/idle.c +++ b/kernel/sched/idle.c @@ -7,6 +7,7 @@ #include <linux/tick.h> #include <linux/mm.h> #include <linux/stackprotector.h> +#include <linux/suspend.h> #include <asm/tlb.h> @@ -47,7 +48,8 @@ static inline int cpu_idle_poll(void) rcu_idle_enter(); trace_cpu_idle_rcuidle(0, smp_processor_id()); local_irq_enable(); - while (!tif_need_resched()) + while (!tif_need_resched() && + (cpu_idle_force_poll || tick_check_broadcast_expired())) cpu_relax(); trace_cpu_idle_rcuidle(PWR_EVENT_EXIT, smp_processor_id()); rcu_idle_exit(); @@ -104,6 +106,21 @@ static void cpuidle_idle_call(void) rcu_idle_enter(); /* + * Suspend-to-idle ("freeze") is a system state in which all user space + * has been frozen, all I/O devices have been suspended and the only + * activity happens here and in iterrupts (if any). In that case bypass + * the cpuidle governor and go stratight for the deepest idle state + * available. Possibly also suspend the local tick and the entire + * timekeeping to prevent timer interrupts from kicking us out of idle + * until a proper wakeup interrupt happens. + */ + if (idle_should_freeze()) { + cpuidle_enter_freeze(); + local_irq_enable(); + goto exit_idle; + } + + /* * Ask the cpuidle framework to choose a convenient idle state. * Fall back to the default arch idle method on errors. */ |