slub: Commonize slab_cache field in struct page
Right now, slab and slub have fields in struct page to derive which
cache a page belongs to, but they do it slightly differently.
slab uses a field called slab_cache, that lives in the third double
word. slub, uses a field called "slab", living outside of the
doublewords area.
Ideally, we could use the same field for this. Since slub heavily makes
use of the doubleword region, there isn't really much room to move
slub's slab_cache field around. Since slab does not have such strict
placement restrictions, we can move it outside the doubleword area.
The naming used by slab, "slab_cache", is less confusing, and it is
preferred over slub's generic "slab".
Signed-off-by: Glauber Costa <glommer@parallels.com>
Acked-by: Christoph Lameter <cl@linux.com>
CC: David Rientjes <rientjes@google.com>
Signed-off-by: Pekka Enberg <penberg@kernel.org>
diff --git a/mm/slub.c b/mm/slub.c
index 16274b2..35483e0 100644
--- a/mm/slub.c
+++ b/mm/slub.c
@@ -1092,11 +1092,11 @@
if (!check_object(s, page, object, SLUB_RED_ACTIVE))
goto out;
- if (unlikely(s != page->slab)) {
+ if (unlikely(s != page->slab_cache)) {
if (!PageSlab(page)) {
slab_err(s, page, "Attempt to free object(0x%p) "
"outside of slab", object);
- } else if (!page->slab) {
+ } else if (!page->slab_cache) {
printk(KERN_ERR
"SLUB <none>: no slab for object 0x%p.\n",
object);
@@ -1357,7 +1357,7 @@
goto out;
inc_slabs_node(s, page_to_nid(page), page->objects);
- page->slab = s;
+ page->slab_cache = s;
__SetPageSlab(page);
if (page->pfmemalloc)
SetPageSlabPfmemalloc(page);
@@ -1424,7 +1424,7 @@
else
page = container_of((struct list_head *)h, struct page, lru);
- __free_slab(page->slab, page);
+ __free_slab(page->slab_cache, page);
}
static void free_slab(struct kmem_cache *s, struct page *page)
@@ -2617,9 +2617,9 @@
page = virt_to_head_page(x);
- if (kmem_cache_debug(s) && page->slab != s) {
+ if (kmem_cache_debug(s) && page->slab_cache != s) {
pr_err("kmem_cache_free: Wrong slab cache. %s but object"
- " is from %s\n", page->slab->name, s->name);
+ " is from %s\n", page->slab_cache->name, s->name);
WARN_ON_ONCE(1);
return;
}
@@ -3418,7 +3418,7 @@
return PAGE_SIZE << compound_order(page);
}
- return slab_ksize(page->slab);
+ return slab_ksize(page->slab_cache);
}
EXPORT_SYMBOL(ksize);
@@ -3443,8 +3443,8 @@
}
slab_lock(page);
- if (on_freelist(page->slab, page, object)) {
- object_err(page->slab, page, object, "Object is on free-list");
+ if (on_freelist(page->slab_cache, page, object)) {
+ object_err(page->slab_cache, page, object, "Object is on free-list");
rv = false;
} else {
rv = true;
@@ -3475,7 +3475,7 @@
__free_pages(page, compound_order(page));
return;
}
- slab_free(page->slab, page, object, _RET_IP_);
+ slab_free(page->slab_cache, page, object, _RET_IP_);
}
EXPORT_SYMBOL(kfree);
@@ -3686,11 +3686,11 @@
if (n) {
list_for_each_entry(p, &n->partial, lru)
- p->slab = s;
+ p->slab_cache = s;
#ifdef CONFIG_SLUB_DEBUG
list_for_each_entry(p, &n->full, lru)
- p->slab = s;
+ p->slab_cache = s;
#endif
}
}