diff options
| -rw-r--r-- | mm/slab.c | 48 |
1 files changed, 27 insertions, 21 deletions
diff --git a/mm/slab.c b/mm/slab.c index b264214c77ea..f81176dd0a90 100644 --- a/mm/slab.c +++ b/mm/slab.c @@ -565,9 +565,31 @@ static inline struct array_cache *cpu_cache_get(struct kmem_cache *cachep) return cachep->array[smp_processor_id()]; } -static size_t slab_mgmt_size(size_t nr_objs, size_t align) +static int calculate_nr_objs(size_t slab_size, size_t buffer_size, + size_t idx_size, size_t align) { - return ALIGN(nr_objs * sizeof(unsigned int), align); + int nr_objs; + size_t freelist_size; + + /* + * Ignore padding for the initial guess. The padding + * is at most @align-1 bytes, and @buffer_size is at + * least @align. In the worst case, this result will + * be one greater than the number of objects that fit + * into the memory allocation when taking the padding + * into account. + */ + nr_objs = slab_size / (buffer_size + idx_size); + + /* + * This calculated number will be either the right + * amount, or one greater than what we want. + */ + freelist_size = slab_size - nr_objs * buffer_size; + if (freelist_size < ALIGN(nr_objs * idx_size, align)) + nr_objs--; + + return nr_objs; } /* @@ -600,25 +622,9 @@ static void cache_estimate(unsigned long gfporder, size_t buffer_size, nr_objs = slab_size / buffer_size; } else { - /* - * Ignore padding for the initial guess. The padding - * is at most @align-1 bytes, and @buffer_size is at - * least @align. In the worst case, this result will - * be one greater than the number of objects that fit - * into the memory allocation when taking the padding - * into account. - */ - nr_objs = (slab_size) / (buffer_size + sizeof(unsigned int)); - - /* - * This calculated number will be either the right - * amount, or one greater than what we want. - */ - if (slab_mgmt_size(nr_objs, align) + nr_objs*buffer_size - > slab_size) - nr_objs--; - - mgmt_size = slab_mgmt_size(nr_objs, align); + nr_objs = calculate_nr_objs(slab_size, buffer_size, + sizeof(unsigned int), align); + mgmt_size = ALIGN(nr_objs * sizeof(unsigned int), align); } *num = nr_objs; *left_over = slab_size - nr_objs*buffer_size - mgmt_size; |