diff options
Diffstat (limited to 'arch/x86_64/kernel/process.c')
| -rw-r--r-- | arch/x86_64/kernel/process.c | 15 |
1 files changed, 9 insertions, 6 deletions
diff --git a/arch/x86_64/kernel/process.c b/arch/x86_64/kernel/process.c index 885c318f76a..458006ae19f 100644 --- a/arch/x86_64/kernel/process.c +++ b/arch/x86_64/kernel/process.c @@ -80,25 +80,25 @@ void idle_notifier_unregister(struct notifier_block *n) } EXPORT_SYMBOL(idle_notifier_unregister); -enum idle_state { CPU_IDLE, CPU_NOT_IDLE }; -static DEFINE_PER_CPU(enum idle_state, idle_state) = CPU_NOT_IDLE; - void enter_idle(void) { - __get_cpu_var(idle_state) = CPU_IDLE; + write_pda(isidle, 1); atomic_notifier_call_chain(&idle_notifier, IDLE_START, NULL); } static void __exit_idle(void) { - __get_cpu_var(idle_state) = CPU_NOT_IDLE; + if (read_pda(isidle) == 0) + return; + write_pda(isidle, 0); atomic_notifier_call_chain(&idle_notifier, IDLE_END, NULL); } /* Called from interrupts to signify idle end */ void exit_idle(void) { - if (current->pid | read_pda(irqcount)) + /* idle loop has pid 0 */ + if (current->pid) return; __exit_idle(); } @@ -220,6 +220,9 @@ void cpu_idle (void) play_dead(); enter_idle(); idle(); + /* In many cases the interrupt that ended idle + has already called exit_idle. But some idle + loops can be woken up without interrupt. */ __exit_idle(); } |