[PATCH 1,2/4 v4] slub: use __cmpxchg_double_slab() at interrupt disabled place

From: Joonsoo Kim
Date: Fri May 18 2012 - 09:02:30 EST


get_freelist(), unfreeze_partials() are only called with interrupt disabled,
so __cmpxchg_double_slab() is suitable.

Acked-by: Christoph Lameter <cl@xxxxxxxxx>
Signed-off-by: Joonsoo Kim <js1304@xxxxxxxxx>
---
According to comment from Pekka, add some comment.

diff --git a/mm/slub.c b/mm/slub.c
index 0c3105c..d7f8291 100644
--- a/mm/slub.c
+++ b/mm/slub.c
@@ -1879,7 +1879,11 @@ redo:
}
}

-/* Unfreeze all the cpu partial slabs */
+/*
+ * Unfreeze all the cpu partial slabs.
+ *
+ * This function must be called with interrupt disabled.
+ */
static void unfreeze_partials(struct kmem_cache *s)
{
struct kmem_cache_node *n = NULL;
@@ -1935,7 +1939,7 @@ static void unfreeze_partials(struct kmem_cache *s)
l = m;
}

- } while (!cmpxchg_double_slab(s, page,
+ } while (!__cmpxchg_double_slab(s, page,
old.freelist, old.counters,
new.freelist, new.counters,
"unfreezing slab"));
@@ -2163,6 +2167,8 @@ static inline void *new_slab_objects(struct kmem_cache *s, gfp_t flags,
* The page is still frozen if the return value is not NULL.
*
* If this function returns NULL then the page has been unfrozen.
+ *
+ * This function must be called with interrupt disabled.
*/
static inline void *get_freelist(struct kmem_cache *s, struct page *page)
{
@@ -2179,7 +2185,7 @@ static inline void *get_freelist(struct kmem_cache *s, struct page *page)
new.inuse = page->objects;
new.frozen = freelist != NULL;

- } while (!cmpxchg_double_slab(s, page,
+ } while (!__cmpxchg_double_slab(s, page,
freelist, counters,
NULL, new.counters,
"get_freelist"));
--
1.7.9.5

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