So don't define it as extern in the header file.
drivers/base/memory.c:28: error: static declaration of 'memory_sysdev_class' follows non-static declaration
include/linux/memory.h:88: error: previous declaration of 'memory_sysdev_class' was here
Cc: Greg KH <greg@kroah.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
extern int register_memory_notifier(struct notifier_block *nb);
extern void unregister_memory_notifier(struct notifier_block *nb);
-extern struct sysdev_class memory_sysdev_class;
#endif /* CONFIG_MEMORY_HOTPLUG */
#define hotplug_memory_notifier(fn, pri) { \