[PATCH] slab: Remove SLAB_NO_REAP option

SLAB_NO_REAP is documented as an option that will cause this slab not to be
reaped under memory pressure.  However, that is not what happens.  The only
thing that SLAB_NO_REAP controls at the moment is the reclaim of the unused
slab elements that were allocated in batch in cache_reap().  Cache_reap()
is run every few seconds independently of memory pressure.

Could we remove the whole thing?  Its only used by three slabs anyways and
I cannot find a reason for having this option.

There is an additional problem with SLAB_NO_REAP.  If set then the recovery
of objects from alien caches is switched off.  Objects not freed on the
same node where they were initially allocated will only be reused if a
certain amount of objects accumulates from one alien node (not very likely)
or if the cache is explicitly shrunk.  (Strangely __cache_shrink does not
check for SLAB_NO_REAP)

Getting rid of SLAB_NO_REAP fixes the problems with alien cache freeing.

Signed-off-by: Christoph Lameter <clameter@sgi.com>
Cc: Pekka Enberg <penberg@cs.helsinki.fi>
Cc: Manfred Spraul <manfred@colorfullife.com>
Cc: Mark Fasheh <mark.fasheh@oracle.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

1 files changed, 0 insertions, 1 deletions

diff --git a/include/linux/slab.h b/include/linux/slab.h
index 38bed95dda7a..2b28c849d75a 100644
--- a/include/linux/slab.h
+++ b/include/linux/slab.h
@@ -38,7 +38,6 @@ typedef struct kmem_cache kmem_cache_t;
 #define SLAB_DEBUG_INITIAL      0x00000200UL    /* Call constructor (as verifier) */
 #define SLAB_RED_ZONE           0x00000400UL    /* Red zone objs in a cache */
 #define SLAB_POISON             0x00000800UL    /* Poison objects */
-#define SLAB_NO_REAP            0x00001000UL    /* never reap from the cache */
 #define SLAB_HWCACHE_ALIGN      0x00002000UL    /* align objs on a h/w cache lines */
 #define SLAB_CACHE_DMA          0x00004000UL    /* use GFP_DMA memory */
 #define SLAB_MUST_HWCACHE_ALIGN 0x00008000UL    /* force alignment */