kernel-ark/include/asm-x86_64/idle.h
Andi Kleen 95833c83f3 [PATCH] x86_64: Add idle notifiers
This adds a new notifier chain that is called with IDLE_START
when a CPU goes idle and IDLE_END when it goes out of idle.
The context can be idle thread or interrupt context.

Since we cannot rely on MONITOR/MWAIT existing the idle
end check currently has to be done in all interrupt
handlers.

They were originally inspired by the similar s390 implementation.

They have a variety of applications:
- They will be needed for CONFIG_NO_IDLE_HZ
- They can be used for oprofile to fix up the missing time
in idle when performance counters don't tick.
- They can be used for better C state management in ACPI
- They could be used for microstate accounting.

This is just infrastructure so far, no users.

Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-01-11 19:04:55 -08:00

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C

#ifndef _ASM_X86_64_IDLE_H
#define _ASM_X86_64_IDLE_H 1
#define IDLE_START 1
#define IDLE_END 2
struct notifier_block;
void idle_notifier_register(struct notifier_block *n);
void idle_notifier_unregister(struct notifier_block *n);
void enter_idle(void);
void exit_idle(void);
#endif