diff --git a/mm/slub.c b/mm/slub.c index 69ee7f807e84..4251917c5da1 100644 --- a/mm/slub.c +++ b/mm/slub.c @@ -133,6 +133,9 @@ */ #define SLUB_UNIMPLEMENTED (SLAB_DEBUG_INITIAL) +/* Mininum number of partial slabs */ +#define MIN_PARTIAL 2 + #define DEBUG_DEFAULT_FLAGS (SLAB_DEBUG_FREE | SLAB_RED_ZONE | \ SLAB_POISON | SLAB_STORE_USER) /* @@ -664,16 +667,8 @@ static int on_freelist(struct kmem_cache *s, struct page *page, void *search) /* * Tracking of fully allocated slabs for debugging */ -static void add_full(struct kmem_cache *s, struct page *page) +static void add_full(struct kmem_cache_node *n, struct page *page) { - struct kmem_cache_node *n; - - VM_BUG_ON(!irqs_disabled()); - - if (!(s->flags & SLAB_STORE_USER)) - return; - - n = get_node(s, page_to_nid(page)); spin_lock(&n->list_lock); list_add(&page->lru, &n->full); spin_unlock(&n->list_lock); @@ -982,10 +977,16 @@ static __always_inline int slab_trylock(struct page *page) /* * Management of partially allocated slabs */ -static void add_partial(struct kmem_cache *s, struct page *page) +static void add_partial_tail(struct kmem_cache_node *n, struct page *page) { - struct kmem_cache_node *n = get_node(s, page_to_nid(page)); + spin_lock(&n->list_lock); + n->nr_partial++; + list_add_tail(&page->lru, &n->partial); + spin_unlock(&n->list_lock); +} +static void add_partial(struct kmem_cache_node *n, struct page *page) +{ spin_lock(&n->list_lock); n->nr_partial++; list_add(&page->lru, &n->partial); @@ -1085,7 +1086,7 @@ static struct page *get_any_partial(struct kmem_cache *s, gfp_t flags) n = get_node(s, zone_to_nid(*z)); if (n && cpuset_zone_allowed_hardwall(*z, flags) && - n->nr_partial > 2) { + n->nr_partial > MIN_PARTIAL) { page = get_partial_node(n); if (page) return page; @@ -1119,15 +1120,31 @@ static struct page *get_partial(struct kmem_cache *s, gfp_t flags, int node) */ static void putback_slab(struct kmem_cache *s, struct page *page) { + struct kmem_cache_node *n = get_node(s, page_to_nid(page)); + if (page->inuse) { + if (page->freelist) - add_partial(s, page); - else if (PageError(page)) - add_full(s, page); + add_partial(n, page); + else if (PageError(page) && (s->flags & SLAB_STORE_USER)) + add_full(n, page); slab_unlock(page); + } else { - slab_unlock(page); - discard_slab(s, page); + if (n->nr_partial < MIN_PARTIAL) { + /* + * Adding an empty page to the partial slabs in order + * to avoid page allocator overhead. This page needs to + * come after all the others that are not fully empty + * in order to make sure that we do maximum + * defragmentation. + */ + add_partial_tail(n, page); + slab_unlock(page); + } else { + slab_unlock(page); + discard_slab(s, page); + } } } @@ -1326,7 +1343,7 @@ checks_ok: * then add it. */ if (unlikely(!prior)) - add_partial(s, page); + add_partial(get_node(s, page_to_nid(page)), page); out_unlock: slab_unlock(page); @@ -1535,7 +1552,7 @@ static struct kmem_cache_node * __init early_kmem_cache_node_alloc(gfp_t gfpflag init_object(kmalloc_caches, n, 1); init_kmem_cache_node(n); atomic_long_inc(&n->nr_slabs); - add_partial(kmalloc_caches, page); + add_partial(n, page); return n; }