Instead of using comments in an attempt at getting the locking right,
use proper assertions that actively warn you if you got it wrong.
Also add extra braces in a few sites to comply with coding-style.
Signed-off-by: Peter Zijlstra <[email protected]>
Signed-off-by: Pekka Enberg <[email protected]>
[ported from ms, resolved conflict with commit 345c905d13a4
("slub: Make cpu partial slab support configurable")]
Signed-off-by: Dmitry Safonov <[email protected]>
---
mm/slub.c | 40 ++++++++++++++++++++--------------------
1 file changed, 20 insertions(+), 20 deletions(-)
diff --git a/mm/slub.c b/mm/slub.c
index 2f07a63..93068da 100644
--- a/mm/slub.c
+++ b/mm/slub.c
@@ -956,23 +956,22 @@ static void trace(struct kmem_cache *s, struct page
*page, void *object,
/*
* Tracking of fully allocated slabs for debugging purposes.
- *
- * list_lock must be held.
*/
static void add_full(struct kmem_cache *s,
struct kmem_cache_node *n, struct page *page)
{
+ lockdep_assert_held(&n->list_lock);
+
if (!(s->flags & SLAB_STORE_USER))
return;
list_add(&page->lru, &n->full);
}
-/*
- * list_lock must be held.
- */
-static void remove_full(struct kmem_cache *s, struct page *page)
+static void remove_full(struct kmem_cache *s, struct kmem_cache_node *n,
struct page *page)
{
+ lockdep_assert_held(&n->list_lock);
+
if (!(s->flags & SLAB_STORE_USER))
return;
@@ -1220,7 +1219,8 @@ static inline int check_object(struct kmem_cache *s, struct page *page,
void *object, u8 val) { return 1; }
static inline void add_full(struct kmem_cache *s, struct kmem_cache_node *n,
struct page *page) {}
-static inline void remove_full(struct kmem_cache *s, struct page *page) {}
+static inline void remove_full(struct kmem_cache *s, struct kmem_cache_node *n,
+ struct page *page) {}
static inline unsigned long kmem_cache_flags(unsigned long object_size,
unsigned long flags, const char *name,
void (*ctor)(void *))
@@ -1507,12 +1507,12 @@ static void discard_slab(struct kmem_cache *s, struct
page *page)
/*
* Management of partially allocated slabs.
- *
- * list_lock must be held.
*/
static inline void add_partial(struct kmem_cache_node *n,
struct page *page, int tail)
{
+ lockdep_assert_held(&n->list_lock);
+
n->nr_partial++;
if (tail == DEACTIVATE_TO_TAIL)
list_add_tail(&page->lru, &n->partial);
@@ -1520,12 +1520,11 @@ static inline void add_partial(struct kmem_cache_node
*n,
list_add(&page->lru, &n->partial);
}
-/*
- * list_lock must be held.
- */
static inline void remove_partial(struct kmem_cache_node *n,
struct page *page)
{
+ lockdep_assert_held(&n->list_lock);
+
list_del(&page->lru);
n->nr_partial--;
}
@@ -1535,8 +1534,6 @@ static inline void remove_partial(struct kmem_cache_node
*n,
* return the pointer to the freelist.
*
* Returns a list of objects or NULL if it fails.
- *
- * Must hold list_lock since we modify the partial list.
*/
static inline void *acquire_slab(struct kmem_cache *s,
struct kmem_cache_node *n, struct page *page,
@@ -1546,6 +1543,8 @@ static inline void *acquire_slab(struct kmem_cache *s,
unsigned long counters;
struct page new;
+ lockdep_assert_held(&n->list_lock);
+
/*
* Zap the freelist and set the frozen bit.
* The old freelist is the list of objects for the
@@ -1893,7 +1892,7 @@ redo:
else if (l == M_FULL)
- remove_full(s, page);
+ remove_full(s, n, page);
if (m == M_PARTIAL) {
@@ -2559,7 +2558,7 @@ static void __slab_free(struct kmem_cache *s, struct page *page,
new.inuse--;
if ((!new.inuse || !prior) && !was_frozen) {
- if (!kmem_cache_debug(s) && !prior)
+ if (!kmem_cache_debug(s) && !prior) {
/*
* Slab was on no list before and will be
partially empty
@@ -2567,7 +2566,7 @@ static void __slab_free(struct kmem_cache *s, struct page
*page,
*/
new.frozen = 1;
- else { /* Needs to be taken off a list */
+ } else { /* Needs to be taken off a list */
n = get_node(s, page_to_nid(page));
/*
@@ -2615,7 +2614,7 @@ static void __slab_free(struct kmem_cache *s, struct page
*page,
* then add it.
*/
if (kmem_cache_debug(s) && unlikely(!prior)) {
- remove_full(s, page);
+ remove_full(s, n, page);
add_partial(n, page, DEACTIVATE_TO_TAIL);
stat(s, FREE_ADD_PARTIAL);
}
@@ -2629,9 +2628,10 @@ slab_empty:
*/
remove_partial(n, page);
stat(s, FREE_REMOVE_PARTIAL);
- } else
+ } else {
/* Slab must be on the full list */
- remove_full(s, page);
+ remove_full(s, n, page);
+ }
spin_unlock_irqrestore(&n->list_lock, flags);
stat(s, FREE_SLAB);
