kernel/cpu.c: create a CPU_STARTING cpu_chain notifier

Right now, there is no notifier that is called on a new cpu, before the new
cpu begins processing interrupts/softirqs.
Various kernel function would need that notification, e.g. kvm works around
by calling smp_call_function_single(), rcu polls cpu_online_map.

The patch adds a CPU_STARTING notification. It also adds a helper function
that sends the message to all cpu_chain handlers.

Tested on x86-64.
All other archs are untested. Especially on sparc, I'm not sure if I got
it right.

Signed-off-by: Manfred Spraul <manfred@colorfullife.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
This commit is contained in:
Manfred Spraul 2008-09-07 16:57:22 +02:00 committed by Ingo Molnar
parent 7686ad5606
commit e545a6140b
17 changed files with 51 additions and 1 deletions

View file

@ -213,9 +213,16 @@ static inline int notifier_to_errno(int ret)
#define CPU_DOWN_FAILED 0x0006 /* CPU (unsigned)v NOT going down */
#define CPU_DEAD 0x0007 /* CPU (unsigned)v dead */
#define CPU_DYING 0x0008 /* CPU (unsigned)v not running any task,
* not handling interrupts, soon dead */
* not handling interrupts, soon dead.
* Called on the dying cpu, interrupts
* are already disabled. Must not
* sleep, must not fail */
#define CPU_POST_DEAD 0x0009 /* CPU (unsigned)v dead, cpu_hotplug
* lock is dropped */
#define CPU_STARTING 0x000A /* CPU (unsigned)v soon running.
* Called on the new cpu, just before
* enabling interrupts. Must not sleep,
* must not fail */
/* Used for CPU hotplug events occuring while tasks are frozen due to a suspend
* operation in progress
@ -229,6 +236,7 @@ static inline int notifier_to_errno(int ret)
#define CPU_DOWN_FAILED_FROZEN (CPU_DOWN_FAILED | CPU_TASKS_FROZEN)
#define CPU_DEAD_FROZEN (CPU_DEAD | CPU_TASKS_FROZEN)
#define CPU_DYING_FROZEN (CPU_DYING | CPU_TASKS_FROZEN)
#define CPU_STARTING_FROZEN (CPU_STARTING | CPU_TASKS_FROZEN)
/* Hibernation and suspend events */
#define PM_HIBERNATION_PREPARE 0x0001 /* Going to hibernate */