[PATCH] cpu hotplug: fix hotplug cpu documentation for proper usage

Update hotplug cpu documentation to clearly state when to use
register_cpu_notifier() and register_hotcpu_notifier.

Signed-off-by: Chandra Seetharaman <sekharan@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This commit is contained in:
Chandra Seetharaman 2006-07-30 03:03:36 -07:00 committed by Linus Torvalds
parent 8c78f3075d
commit 7c7165c908

View file

@ -251,16 +251,24 @@ A: This is what you would need in your kernel code to receive notifications.
return NOTIFY_OK;
}
static struct notifier_block foobar_cpu_notifer =
static struct notifier_block __cpuinitdata foobar_cpu_notifer =
{
.notifier_call = foobar_cpu_callback,
};
You need to call register_cpu_notifier() from your init function.
Init functions could be of two types:
1. early init (init function called when only the boot processor is online).
2. late init (init function called _after_ all the CPUs are online).
In your init function,
For the first case, you should add the following to your init function
register_cpu_notifier(&foobar_cpu_notifier);
For the second case, you should add the following to your init function
register_hotcpu_notifier(&foobar_cpu_notifier);
You can fail PREPARE notifiers if something doesn't work to prepare resources.
This will stop the activity and send a following CANCELED event back.