[PATCH] mm: cleanup swap unused warning

[Con Kolivas <kernel@kolivas.org>]

On Tuesday 16 May 2006 20:55, Con Kolivas wrote:
> Ok so if we fix it by making swp_entry_t __attribute__((__unused__) we
> break swap migration code?
>
> If we make swap_free() an empty static inline function then gcc compiles in
> the variable needlessly and we won't know it.

Rather than assume I checked the generated code and I was wrong (which is
something I'm getting good at being).

The variable is not compiled in so the empty static inline as suggested by
Pekka suffices to silence this warning.

---
if CONFIG_SWAP is not defined we get:

mm/vmscan.c: In function ‘remove_mapping’:
mm/vmscan.c:387: warning: unused variable ‘swap’

Signed-off-by: Con Kolivas <kernel@kolivas.org>

---
 include/linux/swap.h |    5 ++++-
 1 files changed, 4 insertions(+), 1 deletion(-)

Index: linux-2.6.17-rc4/include/linux/swap.h
===================================================================
--- linux-2.6.17-rc4.orig/include/linux/swap.h	2006-05-16 23:07:35.000000000 +1000
+++ linux-2.6.17-rc4/include/linux/swap.h	2006-05-16 23:08:08.000000000 +1000
@@ -292,7 +292,10 @@ static inline void disable_swap_token(vo
 #define show_swap_cache_info()			/*NOTHING*/
 #define free_swap_and_cache(swp)		/*NOTHING*/
 #define swap_duplicate(swp)			/*NOTHING*/
-#define swap_free(swp)				/*NOTHING*/
+static inline void swap_free(swp_entry_t swp)
+{
+}
+
 #define read_swap_cache_async(swp,vma,addr)	NULL
 #define lookup_swap_cache(swp)			NULL
 #define valid_swaphandles(swp, off)		0

-- 
-ck