[patch 6/9] slab: extract slab_{put|get}_obj

From: Pekka Enberg
Date: Tue Jan 03 2006 - 15:25:46 EST


From: Matthew Dobson <colpatch@xxxxxxxxxx>

This patch create two helper functions slab_get_obj() and
slab_put_obj() to replace duplicated code in mm/slab.c

Signed-off-by: Matthew Dobson <colpatch@xxxxxxxxxx>
Acked-by: Manfred Spraul <manfred@xxxxxxxxxxxxxxxx>
Signed-off-by: Pekka Enberg <penberg@xxxxxxxxxxxxxx>
---

mm/slab.c | 77 ++++++++++++++++++++++++++++++++------------------------------
1 file changed, 40 insertions(+), 37 deletions(-)

Index: 2.6/mm/slab.c
===================================================================
--- 2.6.orig/mm/slab.c
+++ 2.6/mm/slab.c
@@ -2196,6 +2196,42 @@ static void kmem_flagcheck(kmem_cache_t
}
}

+static void *slab_get_obj(kmem_cache_t *cachep, struct slab *slabp, int nodeid)
+{
+ void *objp = slabp->s_mem + (slabp->free * cachep->buffer_size);
+ kmem_bufctl_t next;
+
+ slabp->inuse++;
+ next = slab_bufctl(slabp)[slabp->free];
+#if DEBUG
+ slab_bufctl(slabp)[slabp->free] = BUFCTL_FREE;
+ WARN_ON(slabp->nodeid != nodeid);
+#endif
+ slabp->free = next;
+
+ return objp;
+}
+
+static void slab_put_obj(kmem_cache_t *cachep, struct slab *slabp, void *objp,
+ int nodeid)
+{
+ unsigned int objnr = (objp - slabp->s_mem) / cachep->buffer_size;
+
+#if DEBUG
+ /* Verify that the slab belongs to the intended node */
+ WARN_ON(slabp->nodeid != nodeid);
+
+ 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;
@@ -2474,22 +2510,12 @@ 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->buffer_size;
-
- slabp->inuse++;
- next = slab_bufctl(slabp)[slabp->free];
-#if DEBUG
- slab_bufctl(slabp)[slabp->free] = BUFCTL_FREE;
- WARN_ON(numa_node_id() != slabp->nodeid);
-#endif
- slabp->free = next;
+ ac->entry[ac->avail++] = slab_get_obj(cachep, slabp,
+ numa_node_id());
}
check_slabp(cachep, slabp);

@@ -2621,7 +2647,6 @@ 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[nodeid];
@@ -2647,14 +2672,7 @@ retry:

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

- /* get obj pointer */
- obj = slabp->s_mem + slabp->free*cachep->buffer_size;
- slabp->inuse++;
- next = slab_bufctl(slabp)[slabp->free];
-#if DEBUG
- slab_bufctl(slabp)[slabp->free] = BUFCTL_FREE;
-#endif
- slabp->free = next;
+ obj = slab_get_obj(cachep, slabp, nodeid);
check_slabp(cachep, slabp);
l3->free_objects--;
/* move slabp to correct slabp list: */
@@ -2693,29 +2711,14 @@ 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 = page_get_slab(virt_to_page(objp));
l3 = cachep->nodelists[node];
list_del(&slabp->list);
- objnr = (objp - slabp->s_mem) / cachep->buffer_size;
check_spinlock_acquired_node(cachep, node);
check_slabp(cachep, slabp);
-
-#if DEBUG
- /* Verify that the slab belongs to the intended node */
- WARN_ON(slabp->nodeid != node);
-
- 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;
+ slab_put_obj(cachep, slabp, objp, node);
STATS_DEC_ACTIVE(cachep);
- slabp->inuse--;
l3->free_objects++;
check_slabp(cachep, slabp);


--


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