From f02c696800886382198df897b30bb796b46a8dae Mon Sep 17 00:00:00 2001 From: Andrew Morton Date: Mon, 29 Apr 2013 15:08:04 -0700 Subject: [PATCH] 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 Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- include/linux/memory.h | 14 ++++++++++---- include/linux/notifier.h | 5 ++++- 2 files changed, 14 insertions(+), 5 deletions(-) diff --git a/include/linux/memory.h b/include/linux/memory.h index 45e93b4..0ff6598 100644 --- a/include/linux/memory.h +++ b/include/linux/memory.h @@ -18,6 +18,7 @@ #include #include #include +#include #define MIN_MEMORY_BLOCK_SIZE (1UL << SECTION_SIZE_BITS) @@ -127,13 +128,18 @@ enum mem_add_context { BOOT, HOTPLUG }; #endif /* CONFIG_MEMORY_HOTPLUG_SPARSE */ #ifdef CONFIG_MEMORY_HOTPLUG -#define hotplug_memory_notifier(fn, pri) { \ +#define hotplug_memory_notifier(fn, pri) ({ \ static __meminitdata struct notifier_block fn##_mem_nb =\ - { .notifier_call = fn, .priority = pri }; \ + { .notifier_call = fn, .priority = pri };\ register_memory_notifier(&fn##_mem_nb); \ -} +}) +#define register_hotmemory_notifier(nb) register_memory_notifier(nb) +#define unregister_hotmemory_notifier(nb) unregister_memory_notifier(nb) #else -#define hotplug_memory_notifier(fn, pri) do { } while (0) +#define hotplug_memory_notifier(fn, pri) (0) +/* These aren't inline functions due to a GCC bug. */ +#define register_hotmemory_notifier(nb) ({ (void)(nb); 0; }) +#define unregister_hotmemory_notifier(nb) ({ (void)(nb); }) #endif /* diff --git a/include/linux/notifier.h b/include/linux/notifier.h index d65746e..d14a4c3 100644 --- a/include/linux/notifier.h +++ b/include/linux/notifier.h @@ -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; }; -- 2.7.4