[PATCH 13/16] slab: replace free and inuse in struct slab with newly introduced active

From: Joonsoo Kim
Date: Thu Aug 22 2013 - 04:49:51 EST


Now, free in struct slab is same meaning as inuse.
So, remove both and replace them with active.

Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@xxxxxxx>

diff --git a/mm/slab.c b/mm/slab.c
index 98257e4..9dcbb22 100644
--- a/mm/slab.c
+++ b/mm/slab.c
@@ -174,8 +174,7 @@ struct slab {
struct {
struct list_head list;
void *s_mem; /* including colour offset */
- unsigned int inuse; /* num of objs active in slab */
- unsigned int free;
+ unsigned int active; /* num of objs active in slab */
};
};

@@ -1652,7 +1651,7 @@ slab_out_of_memory(struct kmem_cache *cachep, gfp_t gfpflags, int nodeid)
active_slabs++;
}
list_for_each_entry(slabp, &n->slabs_partial, list) {
- active_objs += slabp->inuse;
+ active_objs += slabp->active;
active_slabs++;
}
list_for_each_entry(slabp, &n->slabs_free, list)
@@ -2439,7 +2438,7 @@ static int drain_freelist(struct kmem_cache *cache,

slabp = list_entry(p, struct slab, list);
#if DEBUG
- BUG_ON(slabp->inuse);
+ BUG_ON(slabp->active);
#endif
list_del(&slabp->list);
/*
@@ -2558,9 +2557,8 @@ static struct slab *alloc_slabmgmt(struct kmem_cache *cachep,
slabp = addr + colour_off;
colour_off += cachep->slab_size;
}
- slabp->inuse = 0;
+ slabp->active = 0;
slabp->s_mem = addr + colour_off;
- slabp->free = 0;
return slabp;
}

@@ -2630,12 +2628,11 @@ static void *slab_get_obj(struct kmem_cache *cachep, struct slab *slabp,
{
void *objp;

- slabp->inuse++;
- objp = index_to_obj(cachep, slabp, slab_bufctl(slabp)[slabp->free]);
+ objp = index_to_obj(cachep, slabp, slab_bufctl(slabp)[slabp->active]);
+ slabp->active++;
#if DEBUG
WARN_ON(page_to_nid(virt_to_page(objp)) != nodeid);
#endif
- slabp->free++;

return objp;
}
@@ -2651,7 +2648,7 @@ static void slab_put_obj(struct kmem_cache *cachep, struct slab *slabp,
WARN_ON(page_to_nid(virt_to_page(objp)) != nodeid);

/* Verify double free bug */
- for (i = slabp->free; i < cachep->num; i++) {
+ for (i = slabp->active; i < cachep->num; i++) {
if (slab_bufctl(slabp)[i] == objnr) {
printk(KERN_ERR "slab: double free detected in cache "
"'%s', objp %p\n", cachep->name, objp);
@@ -2659,9 +2656,8 @@ static void slab_put_obj(struct kmem_cache *cachep, struct slab *slabp,
}
}
#endif
- slabp->free--;
- slab_bufctl(slabp)[slabp->free] = objnr;
- slabp->inuse--;
+ slabp->active--;
+ slab_bufctl(slabp)[slabp->active] = objnr;
}

/*
@@ -2896,9 +2892,9 @@ retry:
* there must be at least one object available for
* allocation.
*/
- BUG_ON(slabp->inuse >= cachep->num);
+ BUG_ON(slabp->active >= cachep->num);

- while (slabp->inuse < cachep->num && batchcount--) {
+ while (slabp->active < cachep->num && batchcount--) {
STATS_INC_ALLOCED(cachep);
STATS_INC_ACTIVE(cachep);
STATS_SET_HIGH(cachep);
@@ -2909,7 +2905,7 @@ retry:

/* move slabp to correct slabp list: */
list_del(&slabp->list);
- if (slabp->free == cachep->num)
+ if (slabp->active == cachep->num)
list_add(&slabp->list, &n->slabs_full);
else
list_add(&slabp->list, &n->slabs_partial);
@@ -3194,14 +3190,14 @@ retry:
STATS_INC_ACTIVE(cachep);
STATS_SET_HIGH(cachep);

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

obj = slab_get_obj(cachep, slabp, nodeid);
n->free_objects--;
/* move slabp to correct slabp list: */
list_del(&slabp->list);

- if (slabp->free == cachep->num)
+ if (slabp->active == cachep->num)
list_add(&slabp->list, &n->slabs_full);
else
list_add(&slabp->list, &n->slabs_partial);
@@ -3380,7 +3376,7 @@ static void free_block(struct kmem_cache *cachep, void **objpp, int nr_objects,
n->free_objects++;

/* fixup slab chains */
- if (slabp->inuse == 0) {
+ if (slabp->active == 0) {
if (n->free_objects > n->free_limit) {
n->free_objects -= cachep->num;
/* No need to drop any previously held
@@ -3441,7 +3437,7 @@ free_done:
struct slab *slabp;

slabp = list_entry(p, struct slab, list);
- BUG_ON(slabp->inuse);
+ BUG_ON(slabp->active);

i++;
p = p->next;
@@ -4055,22 +4051,22 @@ void get_slabinfo(struct kmem_cache *cachep, struct slabinfo *sinfo)
spin_lock_irq(&n->list_lock);

list_for_each_entry(slabp, &n->slabs_full, list) {
- if (slabp->inuse != cachep->num && !error)
+ if (slabp->active != cachep->num && !error)
error = "slabs_full accounting error";
active_objs += cachep->num;
active_slabs++;
}
list_for_each_entry(slabp, &n->slabs_partial, list) {
- if (slabp->inuse == cachep->num && !error)
- error = "slabs_partial inuse accounting error";
- if (!slabp->inuse && !error)
- error = "slabs_partial/inuse accounting error";
- active_objs += slabp->inuse;
+ if (slabp->active == cachep->num && !error)
+ error = "slabs_partial accounting error";
+ if (!slabp->active && !error)
+ error = "slabs_partial accounting error";
+ active_objs += slabp->active;
active_slabs++;
}
list_for_each_entry(slabp, &n->slabs_free, list) {
- if (slabp->inuse && !error)
- error = "slabs_free/inuse accounting error";
+ if (slabp->active && !error)
+ error = "slabs_free accounting error";
num_slabs++;
}
free_objects += n->free_objects;
@@ -4232,7 +4228,7 @@ static void handle_slab(unsigned long *n, struct kmem_cache *c, struct slab *s)
for (i = 0, p = s->s_mem; i < c->num; i++, p += c->size) {
bool active = true;

- for (j = s->free; j < c->num; j++) {
+ for (j = s->active; j < c->num; j++) {
/* Skip freed item */
if (slab_bufctl(s)[j] == i) {
active = false;
--
1.7.9.5

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