SLUB: Simplify debug code
Consolidate functionality into the #ifdef section.
Extract tracing into one subroutine.
Move object debug processing into the #ifdef section so that the
code in __slab_alloc and __slab_free becomes minimal.
Reduce number of functions we need to provide stubs for in the !SLUB_DEBUG case.
Signed-off-by: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/mm/slub.c b/mm/slub.c
index e7ad123..98801d4 100644
--- a/mm/slub.c
+++ b/mm/slub.c
@@ -742,6 +742,22 @@
return search == NULL;
}
+static void trace(struct kmem_cache *s, struct page *page, void *object, int alloc)
+{
+ if (s->flags & SLAB_TRACE) {
+ printk(KERN_INFO "TRACE %s %s 0x%p inuse=%d fp=0x%p\n",
+ s->name,
+ alloc ? "alloc" : "free",
+ object, page->inuse,
+ page->freelist);
+
+ if (!alloc)
+ print_section("Object", (void *)object, s->objsize);
+
+ dump_stack();
+ }
+}
+
/*
* Tracking of fully allocated slabs for debugging purposes.
*/
@@ -766,8 +782,18 @@
spin_unlock(&n->list_lock);
}
-static int alloc_object_checks(struct kmem_cache *s, struct page *page,
- void *object)
+static void setup_object_debug(struct kmem_cache *s, struct page *page,
+ void *object)
+{
+ if (!(s->flags & (SLAB_STORE_USER|SLAB_RED_ZONE|__OBJECT_POISON)))
+ return;
+
+ init_object(s, object, 0);
+ init_tracking(s, object);
+}
+
+static int alloc_debug_processing(struct kmem_cache *s, struct page *page,
+ void *object, void *addr)
{
if (!check_slab(s, page))
goto bad;
@@ -782,13 +808,16 @@
goto bad;
}
- if (!object)
- return 1;
-
- if (!check_object(s, page, object, 0))
+ if (object && !check_object(s, page, object, 0))
goto bad;
+ /* Success perform special debug activities for allocs */
+ if (s->flags & SLAB_STORE_USER)
+ set_track(s, object, TRACK_ALLOC, addr);
+ trace(s, page, object, 1);
+ init_object(s, object, 1);
return 1;
+
bad:
if (PageSlab(page)) {
/*
@@ -806,8 +835,8 @@
return 0;
}
-static int free_object_checks(struct kmem_cache *s, struct page *page,
- void *object)
+static int free_debug_processing(struct kmem_cache *s, struct page *page,
+ void *object, void *addr)
{
if (!check_slab(s, page))
goto fail;
@@ -841,29 +870,22 @@
"to slab %s", object, page->slab->name);
goto fail;
}
+
+ /* Special debug activities for freeing objects */
+ if (!SlabFrozen(page) && !page->freelist)
+ remove_full(s, page);
+ if (s->flags & SLAB_STORE_USER)
+ set_track(s, object, TRACK_FREE, addr);
+ trace(s, page, object, 0);
+ init_object(s, object, 0);
return 1;
+
fail:
printk(KERN_ERR "@@@ SLUB: %s slab 0x%p object at 0x%p not freed.\n",
s->name, page, object);
return 0;
}
-static void trace(struct kmem_cache *s, struct page *page, void *object, int alloc)
-{
- if (s->flags & SLAB_TRACE) {
- printk(KERN_INFO "TRACE %s %s 0x%p inuse=%d fp=0x%p\n",
- s->name,
- alloc ? "alloc" : "free",
- object, page->inuse,
- page->freelist);
-
- if (!alloc)
- print_section("Object", (void *)object, s->objsize);
-
- dump_stack();
- }
-}
-
static int __init setup_slub_debug(char *str)
{
if (!str || *str != '=')
@@ -932,26 +954,20 @@
s->flags |= slub_debug;
}
#else
+static inline void setup_object_debug(struct kmem_cache *s,
+ struct page *page, void *object) {}
-static inline int alloc_object_checks(struct kmem_cache *s,
- struct page *page, void *object) { return 0; }
+static inline int alloc_debug_processing(struct kmem_cache *s,
+ struct page *page, void *object, void *addr) { return 0; }
-static inline int free_object_checks(struct kmem_cache *s,
- struct page *page, void *object) { return 0; }
+static inline int free_debug_processing(struct kmem_cache *s,
+ struct page *page, void *object, void *addr) { return 0; }
-static inline void add_full(struct kmem_cache_node *n, struct page *page) {}
-static inline void remove_full(struct kmem_cache *s, struct page *page) {}
-static inline void trace(struct kmem_cache *s, struct page *page,
- void *object, int alloc) {}
-static inline void init_object(struct kmem_cache *s,
- void *object, int active) {}
-static inline void init_tracking(struct kmem_cache *s, void *object) {}
static inline int slab_pad_check(struct kmem_cache *s, struct page *page)
{ return 1; }
static inline int check_object(struct kmem_cache *s, struct page *page,
void *object, int active) { return 1; }
-static inline void set_track(struct kmem_cache *s, void *object,
- enum track_item alloc, void *addr) {}
+static inline void add_full(struct kmem_cache_node *n, struct page *page) {}
static inline void kmem_cache_open_debug_check(struct kmem_cache *s) {}
#define slub_debug 0
#endif
@@ -988,11 +1004,7 @@
static void setup_object(struct kmem_cache *s, struct page *page,
void *object)
{
- if (SlabDebug(page)) {
- init_object(s, object, 0);
- init_tracking(s, object);
- }
-
+ setup_object_debug(s, page, object);
if (unlikely(s->ctor))
s->ctor(object, s, 0);
}
@@ -1449,12 +1461,8 @@
return NULL;
debug:
object = page->freelist;
- if (!alloc_object_checks(s, page, object))
+ if (!alloc_debug_processing(s, page, object, addr))
goto another_slab;
- if (s->flags & SLAB_STORE_USER)
- set_track(s, object, TRACK_ALLOC, addr);
- trace(s, page, object, 1);
- init_object(s, object, 1);
page->inuse++;
page->freelist = object[page->offset];
@@ -1561,14 +1569,8 @@
return;
debug:
- if (!free_object_checks(s, page, x))
+ if (!free_debug_processing(s, page, x, addr))
goto out_unlock;
- if (!SlabFrozen(page) && !page->freelist)
- remove_full(s, page);
- if (s->flags & SLAB_STORE_USER)
- set_track(s, x, TRACK_FREE, addr);
- trace(s, page, object, 0);
- init_object(s, object, 0);
goto checks_ok;
}
@@ -1805,7 +1807,7 @@
page->freelist = get_freepointer(kmalloc_caches, n);
page->inuse++;
kmalloc_caches->node[node] = n;
- init_object(kmalloc_caches, n, 1);
+ setup_object_debug(kmalloc_caches, page, n);
init_kmem_cache_node(n);
atomic_long_inc(&n->nr_slabs);
add_partial(n, page);