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Diffstat (limited to 'arch/x86_64/kernel/process.c')
-rw-r--r--arch/x86_64/kernel/process.c15
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();
}