Add the two methods needed for defragmentation and add the display of the
methods via the proc interface.
Add documentation explaining the use of these methods and the prototypes
for slab.h. Add functions to setup the defrag methods for a slab cache.
Add empty functions for SLAB/SLOB. The API is generic so it
could be theoretically implemented for either allocator.
Reviewed-by: Rik van Riel <riel@redhat.com>
Signed-off-by: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi>
Signed-off-by: Christoph Lameter <cl@linux-foundation.org>
---
include/linux/slab.h | 50 +++++++++++++++++++++++++++++++++++++++++++++++
include/linux/slub_def.h | 3 ++
mm/slub.c | 29 ++++++++++++++++++++++++++-
3 files changed, 81 insertions(+), 1 deletion(-)
Index: linux-2.6/include/linux/slub_def.h
===================================================================
--- linux-2.6.orig/include/linux/slub_def.h 2008-07-31 12:19:28.000000000 -0500
+++ linux-2.6/include/linux/slub_def.h 2008-07-31 12:19:39.000000000 -0500
@@ -86,6 +86,9 @@
gfp_t allocflags; /* gfp flags to use on each alloc */
int refcount; /* Refcount for slab cache destroy */
void (*ctor)(void *);
+ kmem_defrag_get_func *get;
+ kmem_defrag_kick_func *kick;
+
int inuse; /* Offset to metadata */
int align; /* Alignment */
int defrag_ratio; /*
Index: linux-2.6/mm/slub.c
===================================================================
--- linux-2.6.orig/mm/slub.c 2008-07-31 12:19:28.000000000 -0500
+++ linux-2.6/mm/slub.c 2008-07-31 12:19:48.000000000 -0500
@@ -2736,6 +2736,19 @@
}
EXPORT_SYMBOL(kfree);
+void kmem_cache_setup_defrag(struct kmem_cache *s,
+ kmem_defrag_get_func get, kmem_defrag_kick_func kick)
+{
+ /*
+ * Defragmentable slabs must have a ctor otherwise objects may be
+ * in an undetermined state after they are allocated.
+ */
+ BUG_ON(!s->ctor);
+ s->get = get;
+ s->kick = ...
