[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>
diff --git a/drivers/scsi/iscsi_tcp.c b/drivers/scsi/iscsi_tcp.c
index ff79e68..7b82ff0 100644
--- a/drivers/scsi/iscsi_tcp.c
+++ b/drivers/scsi/iscsi_tcp.c
@@ -3639,7 +3639,7 @@
taskcache = kmem_cache_create("iscsi_taskcache",
sizeof(struct iscsi_data_task), 0,
- SLAB_HWCACHE_ALIGN | SLAB_NO_REAP, NULL, NULL);
+ SLAB_HWCACHE_ALIGN, NULL, NULL);
if (!taskcache)
return -ENOMEM;
diff --git a/fs/ocfs2/super.c b/fs/ocfs2/super.c
index 8dd3aaf..09e1c57 100644
--- a/fs/ocfs2/super.c
+++ b/fs/ocfs2/super.c
@@ -959,7 +959,7 @@
ocfs2_lock_cache = kmem_cache_create("ocfs2_lock",
sizeof(struct ocfs2_journal_lock),
0,
- SLAB_NO_REAP|SLAB_HWCACHE_ALIGN,
+ SLAB_HWCACHE_ALIGN,
NULL, NULL);
if (!ocfs2_lock_cache)
return -ENOMEM;
diff --git a/include/linux/slab.h b/include/linux/slab.h
index 38bed95..2b28c84 100644
--- a/include/linux/slab.h
+++ b/include/linux/slab.h
@@ -38,7 +38,6 @@
#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 */
diff --git a/mm/slab.c b/mm/slab.c
index 5c25749..2423550 100644
--- a/mm/slab.c
+++ b/mm/slab.c
@@ -170,12 +170,12 @@
#if DEBUG
# define CREATE_MASK (SLAB_DEBUG_INITIAL | SLAB_RED_ZONE | \
SLAB_POISON | SLAB_HWCACHE_ALIGN | \
- SLAB_NO_REAP | SLAB_CACHE_DMA | \
+ SLAB_CACHE_DMA | \
SLAB_MUST_HWCACHE_ALIGN | SLAB_STORE_USER | \
SLAB_RECLAIM_ACCOUNT | SLAB_PANIC | \
SLAB_DESTROY_BY_RCU)
#else
-# define CREATE_MASK (SLAB_HWCACHE_ALIGN | SLAB_NO_REAP | \
+# define CREATE_MASK (SLAB_HWCACHE_ALIGN | \
SLAB_CACHE_DMA | SLAB_MUST_HWCACHE_ALIGN | \
SLAB_RECLAIM_ACCOUNT | SLAB_PANIC | \
SLAB_DESTROY_BY_RCU)
@@ -662,7 +662,6 @@
.limit = BOOT_CPUCACHE_ENTRIES,
.shared = 1,
.buffer_size = sizeof(struct kmem_cache),
- .flags = SLAB_NO_REAP,
.name = "kmem_cache",
#if DEBUG
.obj_size = sizeof(struct kmem_cache),
@@ -1848,9 +1847,6 @@
* %SLAB_RED_ZONE - Insert `Red' zones around the allocated memory to check
* for buffer overruns.
*
- * %SLAB_NO_REAP - Don't automatically reap this cache when we're under
- * memory pressure.
- *
* %SLAB_HWCACHE_ALIGN - Align the objects in this cache to a hardware
* cacheline. This can be beneficial if you're counting cycles as closely
* as davem.
@@ -3584,10 +3580,6 @@
struct slab *slabp;
searchp = list_entry(walk, struct kmem_cache, next);
-
- if (searchp->flags & SLAB_NO_REAP)
- goto next;
-
check_irq_on();
l3 = searchp->nodelists[numa_node_id()];
@@ -3635,7 +3627,6 @@
} while (--tofree > 0);
next_unlock:
spin_unlock_irq(&l3->list_lock);
-next:
cond_resched();
}
check_irq_on();