diff options
Diffstat (limited to 'mm')
| -rw-r--r-- | mm/slab.c | 21 |
1 files changed, 21 insertions, 0 deletions
diff --git a/mm/slab.c b/mm/slab.c index 878354b26b72..9d4c7b50dfdc 100644 --- a/mm/slab.c +++ b/mm/slab.c @@ -157,6 +157,17 @@ #define ARCH_KMALLOC_FLAGS SLAB_HWCACHE_ALIGN #endif +#define FREELIST_BYTE_INDEX (((PAGE_SIZE >> BITS_PER_BYTE) \ + <= SLAB_OBJ_MIN_SIZE) ? 1 : 0) + +#if FREELIST_BYTE_INDEX +typedef unsigned char freelist_idx_t; +#else +typedef unsigned short freelist_idx_t; +#endif + +#define SLAB_OBJ_MAX_NUM (1 << sizeof(freelist_idx_t) * BITS_PER_BYTE) + /* * true if a page was allocated from pfmemalloc reserves for network-based * swap @@ -2016,6 +2027,10 @@ static size_t calculate_slab_order(struct kmem_cache *cachep, if (!num) continue; + /* Can't handle number of objects more than SLAB_OBJ_MAX_NUM */ + if (num > SLAB_OBJ_MAX_NUM) + break; + if (flags & CFLGS_OFF_SLAB) { /* * Max number of objs-per-slab for caches which @@ -2258,6 +2273,12 @@ __kmem_cache_create (struct kmem_cache *cachep, unsigned long flags) flags |= CFLGS_OFF_SLAB; size = ALIGN(size, cachep->align); + /* + * We should restrict the number of objects in a slab to implement + * byte sized index. Refer comment on SLAB_OBJ_MIN_SIZE definition. + */ + if (FREELIST_BYTE_INDEX && size < SLAB_OBJ_MIN_SIZE) + size = ALIGN(SLAB_OBJ_MIN_SIZE, cachep->align); left_over = calculate_slab_order(cachep, size, cachep->align, flags); |