include/linux/memory.h: implement register_hotmemory_notifier()

When CONFIG_MEMORY_HOTPLUG=n, we don't want the memory-hotplug notifier
handlers to be included in the .o files, for space reasons.

The existing hotplug_memory_notifier() tries to handle this but testing
with gcc-4.4.4 shows that it doesn't work - the hotplug functions are
still present in the .o files.

So implement a new register_hotmemory_notifier() which is a copy of
register_hotcpu_notifier(), and which actually works as desired.
hotplug_memory_notifier() and register_memory_notifier() callsites
should be converted to use this new register_hotmemory_notifier().

While we're there, let's repair the existing hotplug_memory_notifier():
it simply stomps on the register_memory_notifier() return value, so
well-behaved code cannot check for errors.  Apparently non of the
existing callers were well-behaved :(

Cc: Andrew Shewmaker <agshew@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Andrew Morton
2013-04-29 15:08:04 -07:00
committed by Linus Torvalds
parent f9d531b8dc
commit f02c696800
2 changed files with 14 additions and 5 deletions

View File

@@ -47,8 +47,11 @@
* runtime initialization.
*/
typedef int (*notifier_fn_t)(struct notifier_block *nb,
unsigned long action, void *data);
struct notifier_block {
int (*notifier_call)(struct notifier_block *, unsigned long, void *);
notifier_fn_t notifier_call;
struct notifier_block __rcu *next;
int priority;
};