[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, 2 insertions, 0 deletions

diff --git a/mm/swap.c b/mm/swap.c
index 017e72ca9bbb..2ed7be39795e 100644
--- a/mm/swap.c
+++ b/mm/swap.c
@@ -514,5 +514,7 @@ void __init swap_setup(void)
          * Right now other parts of the system means that we
          * _really_ don't want to cluster much more
          */
+#ifdef CONFIG_HOTPLUG_CPU
         hotcpu_notifier(cpu_swap_callback, 0);
+#endif
 }