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-rw-r--r--include/linux/slub_def.h2
-rw-r--r--mm/slub.c39
2 files changed, 30 insertions, 11 deletions
diff --git a/include/linux/slub_def.h b/include/linux/slub_def.h
index 4236b5dee81..71e43a12ebb 100644
--- a/include/linux/slub_def.h
+++ b/include/linux/slub_def.h
@@ -29,6 +29,7 @@ enum stat_item {
DEACTIVATE_TO_HEAD, /* Cpu slab was moved to the head of partials */
DEACTIVATE_TO_TAIL, /* Cpu slab was moved to the tail of partials */
DEACTIVATE_REMOTE_FREES,/* Slab contained remotely freed objects */
+ ORDER_FALLBACK, /* Number of times fallback was necessary */
NR_SLUB_STAT_ITEMS };
struct kmem_cache_cpu {
@@ -81,6 +82,7 @@ struct kmem_cache {
/* Allocation and freeing of slabs */
struct kmem_cache_order_objects max;
+ struct kmem_cache_order_objects min;
gfp_t allocflags; /* gfp flags to use on each alloc */
int refcount; /* Refcount for slab cache destroy */
void (*ctor)(struct kmem_cache *, void *);
diff --git a/mm/slub.c b/mm/slub.c
index c8514e93ffd..35c22d940ba 100644
--- a/mm/slub.c
+++ b/mm/slub.c
@@ -1113,28 +1113,43 @@ static inline void dec_slabs_node(struct kmem_cache *s, int node,
/*
* Slab allocation and freeing
*/
+static inline struct page *alloc_slab_page(gfp_t flags, int node,
+ struct kmem_cache_order_objects oo)
+{
+ int order = oo_order(oo);
+
+ if (node == -1)
+ return alloc_pages(flags, order);
+ else
+ return alloc_pages_node(node, flags, order);
+}
+
static struct page *allocate_slab(struct kmem_cache *s, gfp_t flags, int node)
{
struct page *page;
struct kmem_cache_order_objects oo = s->oo;
- int order = oo_order(oo);
- int pages = 1 << order;
flags |= s->allocflags;
- if (node == -1)
- page = alloc_pages(flags, order);
- else
- page = alloc_pages_node(node, flags, order);
-
- if (!page)
- return NULL;
+ page = alloc_slab_page(flags | __GFP_NOWARN | __GFP_NORETRY, node,
+ oo);
+ if (unlikely(!page)) {
+ oo = s->min;
+ /*
+ * Allocation may have failed due to fragmentation.
+ * Try a lower order alloc if possible
+ */
+ page = alloc_slab_page(flags, node, oo);
+ if (!page)
+ return NULL;
+ stat(get_cpu_slab(s, raw_smp_processor_id()), ORDER_FALLBACK);
+ }
page->objects = oo_objects(oo);
mod_zone_page_state(page_zone(page),
(s->flags & SLAB_RECLAIM_ACCOUNT) ?
NR_SLAB_RECLAIMABLE : NR_SLAB_UNRECLAIMABLE,
- pages);
+ 1 << oo_order(oo));
return page;
}
@@ -2347,6 +2362,7 @@ static int calculate_sizes(struct kmem_cache *s)
* Determine the number of objects per slab
*/
s->oo = oo_make(order, size);
+ s->min = oo_make(get_order(size), size);
if (oo_objects(s->oo) > oo_objects(s->max))
s->max = s->oo;
@@ -4163,7 +4179,7 @@ STAT_ATTR(DEACTIVATE_EMPTY, deactivate_empty);
STAT_ATTR(DEACTIVATE_TO_HEAD, deactivate_to_head);
STAT_ATTR(DEACTIVATE_TO_TAIL, deactivate_to_tail);
STAT_ATTR(DEACTIVATE_REMOTE_FREES, deactivate_remote_frees);
-
+STAT_ATTR(ORDER_FALLBACK, order_fallback);
#endif
static struct attribute *slab_attrs[] = {
@@ -4216,6 +4232,7 @@ static struct attribute *slab_attrs[] = {
&deactivate_to_head_attr.attr,
&deactivate_to_tail_attr.attr,
&deactivate_remote_frees_attr.attr,
+ &order_fallback_attr.attr,
#endif
NULL
};