Slab defrag: get and kick kmem_cache_ops methods

Add the two methods and add the display of the methods via the proc interface.

Signed-off-by: Christoph Lameter <clameter@sgi.com>

---
 include/linux/slab.h |   31 +++++++++++++++++++++++++++++++
 mm/slub.c            |   14 ++++++++++++++
 2 files changed, 45 insertions(+)

Index: linux-2.6.23-rc1/include/linux/slab.h
===================================================================
--- linux-2.6.23-rc1.orig/include/linux/slab.h	2007-07-29 00:30:52.000000000 -0700
+++ linux-2.6.23-rc1/include/linux/slab.h	2007-07-29 00:33:28.000000000 -0700
@@ -53,6 +53,37 @@ int slab_is_available(void);
 
 struct kmem_cache_ops {
 	void (*ctor)(void *, struct kmem_cache *, unsigned long);
+
+	/*
+	 * Called with slab lock held and interrupts disabled.
+	 * No slab operation may be performed.
+	 *
+	 * Parameters passed are the number of objects to process
+	 * and an array of pointers to objects for which we
+	 * need references.
+	 *
+	 * Returns a pointer that is passed to the kick function.
+	 * If all objects cannot be moved then the pointer may
+	 * indicate that this wont work and then kick can simply
+	 * remove the references that were already obtained.
+	 *
+	 * The array passed to get() is also passed to kick(). The
+	 * function may remove objects by setting array elements to NULL.
+	 */
+	void *(*get)(struct kmem_cache *, int nr, void **);
+
+	/*
+	 * Called with no locks held and interrupts enabled.
+	 * Any operation may be performed in kick().
+	 *
+	 * Parameters passed are the number of objects in the array,
+	 * the array of pointers to the objects and the pointer
+	 * returned by get().
+	 *
+	 * Success is checked by examining the number of remaining
+	 * objects in the slab.
+	 */
+	void (*kick)(struct kmem_cache *, int nr, void **, void *private);
 };
 
 struct kmem_cache *kmem_cache_create(const char *, size_t, size_t,
Index: linux-2.6.23-rc1/mm/slub.c
===================================================================
--- linux-2.6.23-rc1.orig/mm/slub.c	2007-07-29 00:33:22.000000000 -0700
+++ linux-2.6.23-rc1/mm/slub.c	2007-07-29 00:33:28.000000000 -0700
@@ -3324,6 +3324,20 @@ static ssize_t ops_show(struct kmem_cach
 		x += sprint_symbol(buf + x, (unsigned long)s->ops->ctor);
 		x += sprintf(buf + x, "\n");
 	}
+
+	if (s->ops->get) {
+		x += sprintf(buf + x, "get : ");
+		x += sprint_symbol(buf + x,
+				(unsigned long)s->ops->get);
+		x += sprintf(buf + x, "\n");
+	}
+
+	if (s->ops->kick) {
+		x += sprintf(buf + x, "kick : ");
+		x += sprint_symbol(buf + x,
+				(unsigned long)s->ops->kick);
+		x += sprintf(buf + x, "\n");
+	}
 	return x;
 }
 SLAB_ATTR_RO(ops);