[RFC][PATCH 5/8] get_object/return_object

Matthew Dobson
2005-11-18T19:43:19Z

[-- Attachment #1: Type: text/plain, Size: 88 bytes --]

Move the code to get/return an object back to its slab into their own
functions.

-Matt

[-- Attachment #2: slab_prep-get_return_object.patch --]
[-- Type: text/x-patch, Size: 3855 bytes --]

Create two helper functions: get_object_from_slab() & return_object_to_slab().
Use these two helper function to replace duplicated code in mm/slab.c

These functions will also be reused by a later patch in this series.

Signed-off-by: Matthew Dobson <colpatch@us.ibm.com>

Index: linux-2.6.15-rc1+critical_pool/mm/slab.c
===================================================================
--- linux-2.6.15-rc1+critical_pool.orig/mm/slab.c 2005-11-17 16:39:24.401412160 -0800
+++ linux-2.6.15-rc1+critical_pool/mm/slab.c 2005-11-17 16:45:07.337277984 -0800
@@ -2148,6 +2148,42 @@ static void kmem_flagcheck(kmem_cache_t
}
}

+static void *get_object(kmem_cache_t *cachep, struct slab *slabp, int nid)
+{
+ void *obj = slabp->s_mem + (slabp->free * cachep->objsize);
+ kmem_bufctl_t next;
+
+ slabp->inuse++;
+ next = slab_bufctl(slabp)[slabp->free];
+#if DEBUG
+ slab_bufctl(slabp)[slabp->free] = BUFCTL_FREE;
+ WARN_ON(slabp->nid != nid);
+#endif
+ slabp->free = next;
+
+ return obj;
+}
+
+static void return_object(kmem_cache_t *cachep, struct slab *slabp, void *objp,
+ int nid)
+{
+ unsigned int objnr = (objp - slabp->s_mem) / cachep->objsize;
+
+#if DEBUG
+ /* Verify that the slab belongs to the intended node */
+ WARN_ON(slabp->nid != nid);
+
+ if (slab_bufctl(slabp)[objnr] != BUFCTL_FREE) {
+ printk(KERN_ERR "slab: double free detected in cache "
+ "'%s', objp %p\n", cachep->name, objp);
+ BUG();
+ }
+#endif
+ slab_bufctl(slabp)[objnr] = slabp->free;
+ slabp->free = objnr;
+ slabp->inuse--;
+}
+
static void set_slab_attr(kmem_cache_t *cachep, struct slab *slabp, void *objp)
{
int i;
@@ -2436,22 +2472,12 @@ retry:
check_slabp(cachep, slabp);
check_spinlock_acquired(cachep);
while (slabp->inuse < cachep->num && batchcount--) {
- kmem_bufctl_t next;
STATS_INC_ALLOCED(cachep);
STATS_INC_ACTIVE(cachep);
STATS_SET_HIGH(cachep);

- /* get obj pointer */
- ac->entry[ac->avail++] = slabp->s_mem +
- slabp->free*cachep->objsize;
-
- slabp->inuse++;
- next = slab_bufctl(slabp)[slabp->free];
-#if DEBUG
- slab_bufctl(slabp)[slabp->free] = BUFCTL_FREE;
- WARN_ON(numa_node_id() != slabp->nid);
-#endif
- slabp->free = next;
+ ac->entry[ac->avail++] = get_object(cachep, slabp,
+ numa_node_id());
}
check_slabp(cachep, slabp);

@@ -2586,7 +2612,6 @@ static void *__cache_alloc_node(kmem_cac
struct slab *slabp;
struct kmem_list3 *l3;
void *obj;
- kmem_bufctl_t next;
int x;

l3 = cachep->nodelists[nid];
@@ -2612,14 +2637,7 @@ retry:

BUG_ON(slabp->inuse == cachep->num);

- /* get obj pointer */
- obj = slabp->s_mem + slabp->free * cachep->objsize;
- slabp->inuse++;
- next = slab_bufctl(slabp)[slabp->free];
-#if DEBUG
- slab_bufctl(slabp)[slabp->free] = BUFCTL_FREE;
-#endif
- slabp->free = next;
+ obj = get_object(cachep, slabp, nid);
check_slabp(cachep, slabp);
l3->free_objects--;
/* move slabp to correct slabp list: */
@@ -2659,29 +2677,14 @@ static void free_block(kmem_cache_t *cac
for (i = 0; i < nr_objects; i++) {
void *objp = objpp[i];
struct slab *slabp;
- unsigned int objnr;

slabp = GET_PAGE_SLAB(virt_to_page(objp));
l3 = cachep->nodelists[nid];
list_del(&slabp->list);
- objnr = (objp - slabp->s_mem) / cachep->objsize;
check_spinlock_acquired_node(cachep, nid);
check_slabp(cachep, slabp);
-
-#if DEBUG
- /* Verify that the slab belongs to the intended node */
- WARN_ON(slabp->nid != nid);
-
- if (slab_bufctl(slabp)[objnr] != BUFCTL_FREE) {
- printk(KERN_ERR "slab: double free detected in cache "
- "'%s', objp %p\n", cachep->name, objp);
- BUG();
- }
-#endif
- slab_bufctl(slabp)[objnr] = slabp->free;
- slabp->free = objnr;
+ return_object(cachep, slabp, objp, nid);
STATS_DEC_ACTIVE(cachep);
- slabp->inuse--;
l3->free_objects++;
check_slabp(cachep, slabp);