[PATCH] hotplug CPU: clean up hotcpu_notifier() use

There was lots of #ifdef noise in the kernel due to hotcpu_notifier(fn,
prio) not correctly marking 'fn' as used in the !HOTPLUG_CPU case, and thus
generating compiler warnings of unused symbols, hence forcing people to add
#ifdefs.

the compiler can skip truly unused functions just fine:

    text    data     bss     dec     hex filename
 1624412  728710 3674856 6027978  5bfaca vmlinux.before
 1624412  728710 3674856 6027978  5bfaca vmlinux.after

[akpm@osdl.org: topology.c fix]
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

1 files changed, 3 insertions, 3 deletions

diff --git a/include/linux/cpu.h b/include/linux/cpu.h
index f02d71bf6894..71dc6ba4f73f 100644
--- a/include/linux/cpu.h
+++ b/include/linux/cpu.h
@@ -89,9 +89,9 @@ int cpu_down(unsigned int cpu);
 #define lock_cpu_hotplug()      do { } while (0)
 #define unlock_cpu_hotplug()    do { } while (0)
 #define lock_cpu_hotplug_interruptible() 0
-#define hotcpu_notifier(fn, pri)        do { } while (0)
-#define register_hotcpu_notifier(nb)    do { } while (0)
-#define unregister_hotcpu_notifier(nb)  do { } while (0)
+#define hotcpu_notifier(fn, pri)        do { (void)(fn); } while (0)
+#define register_hotcpu_notifier(nb)    do { (void)(nb); } while (0)
+#define unregister_hotcpu_notifier(nb)  do { (void)(nb); } while (0)
 
 /* CPUs don't go offline once they're online w/o CONFIG_HOTPLUG_CPU */
 static inline int cpu_is_offline(int cpu) { return 0; }