diff options
| -rw-r--r-- | mm/zsmalloc.c | 80 |
1 files changed, 66 insertions, 14 deletions
diff --git a/mm/zsmalloc.c b/mm/zsmalloc.c index 839a48c3ca27..b3b57ef85830 100644 --- a/mm/zsmalloc.c +++ b/mm/zsmalloc.c @@ -214,7 +214,7 @@ struct link_free { }; struct zs_pool { - struct size_class size_class[ZS_SIZE_CLASSES]; + struct size_class *size_class[ZS_SIZE_CLASSES]; gfp_t flags; /* allocation flags used when growing pool */ atomic_long_t pages_allocated; @@ -468,7 +468,7 @@ static enum fullness_group fix_fullness_group(struct zs_pool *pool, if (newfg == currfg) goto out; - class = &pool->size_class[class_idx]; + class = pool->size_class[class_idx]; remove_zspage(page, class, currfg); insert_zspage(page, class, newfg); set_zspage_mapping(page, class_idx, newfg); @@ -925,6 +925,23 @@ fail: return notifier_to_errno(ret); } +static unsigned int get_maxobj_per_zspage(int size, int pages_per_zspage) +{ + return pages_per_zspage * PAGE_SIZE / size; +} + +static bool can_merge(struct size_class *prev, int size, int pages_per_zspage) +{ + if (prev->pages_per_zspage != pages_per_zspage) + return false; + + if (get_maxobj_per_zspage(prev->size, prev->pages_per_zspage) + != get_maxobj_per_zspage(size, pages_per_zspage)) + return false; + + return true; +} + /** * zs_create_pool - Creates an allocation pool to work from. * @flags: allocation flags used to allocate pool metadata @@ -945,25 +962,56 @@ struct zs_pool *zs_create_pool(gfp_t flags) if (!pool) return NULL; - for (i = 0; i < ZS_SIZE_CLASSES; i++) { + /* + * Iterate reversly, because, size of size_class that we want to use + * for merging should be larger or equal to current size. + */ + for (i = ZS_SIZE_CLASSES - 1; i >= 0; i--) { int size; + int pages_per_zspage; struct size_class *class; + struct size_class *prev_class; size = ZS_MIN_ALLOC_SIZE + i * ZS_SIZE_CLASS_DELTA; if (size > ZS_MAX_ALLOC_SIZE) size = ZS_MAX_ALLOC_SIZE; + pages_per_zspage = get_pages_per_zspage(size); + + /* + * size_class is used for normal zsmalloc operation such + * as alloc/free for that size. Although it is natural that we + * have one size_class for each size, there is a chance that we + * can get more memory utilization if we use one size_class for + * many different sizes whose size_class have same + * characteristics. So, we makes size_class point to + * previous size_class if possible. + */ + if (i < ZS_SIZE_CLASSES - 1) { + prev_class = pool->size_class[i + 1]; + if (can_merge(prev_class, size, pages_per_zspage)) { + pool->size_class[i] = prev_class; + continue; + } + } + + class = kzalloc(sizeof(struct size_class), GFP_KERNEL); + if (!class) + goto err; - class = &pool->size_class[i]; class->size = size; class->index = i; + class->pages_per_zspage = pages_per_zspage; spin_lock_init(&class->lock); - class->pages_per_zspage = get_pages_per_zspage(size); - + pool->size_class[i] = class; } pool->flags = flags; return pool; + +err: + zs_destroy_pool(pool); + return NULL; } EXPORT_SYMBOL_GPL(zs_create_pool); @@ -973,7 +1021,13 @@ void zs_destroy_pool(struct zs_pool *pool) for (i = 0; i < ZS_SIZE_CLASSES; i++) { int fg; - struct size_class *class = &pool->size_class[i]; + struct size_class *class = pool->size_class[i]; + + if (!class) + continue; + + if (class->index != i) + continue; for (fg = 0; fg < _ZS_NR_FULLNESS_GROUPS; fg++) { if (class->fullness_list[fg]) { @@ -981,6 +1035,7 @@ void zs_destroy_pool(struct zs_pool *pool) class->size, fg); } } + kfree(class); } kfree(pool); } @@ -999,7 +1054,6 @@ unsigned long zs_malloc(struct zs_pool *pool, size_t size) { unsigned long obj; struct link_free *link; - int class_idx; struct size_class *class; struct page *first_page, *m_page; @@ -1008,9 +1062,7 @@ unsigned long zs_malloc(struct zs_pool *pool, size_t size) if (unlikely(!size || size > ZS_MAX_ALLOC_SIZE)) return 0; - class_idx = get_size_class_index(size); - class = &pool->size_class[class_idx]; - BUG_ON(class_idx != class->index); + class = pool->size_class[get_size_class_index(size)]; spin_lock(&class->lock); first_page = find_get_zspage(class); @@ -1063,7 +1115,7 @@ void zs_free(struct zs_pool *pool, unsigned long obj) first_page = get_first_page(f_page); get_zspage_mapping(first_page, &class_idx, &fullness); - class = &pool->size_class[class_idx]; + class = pool->size_class[class_idx]; f_offset = obj_idx_to_offset(f_page, f_objidx, class->size); spin_lock(&class->lock); @@ -1124,7 +1176,7 @@ void *zs_map_object(struct zs_pool *pool, unsigned long handle, obj_handle_to_location(handle, &page, &obj_idx); get_zspage_mapping(get_first_page(page), &class_idx, &fg); - class = &pool->size_class[class_idx]; + class = pool->size_class[class_idx]; off = obj_idx_to_offset(page, obj_idx, class->size); area = &get_cpu_var(zs_map_area); @@ -1158,7 +1210,7 @@ void zs_unmap_object(struct zs_pool *pool, unsigned long handle) obj_handle_to_location(handle, &page, &obj_idx); get_zspage_mapping(get_first_page(page), &class_idx, &fg); - class = &pool->size_class[class_idx]; + class = pool->size_class[class_idx]; off = obj_idx_to_offset(page, obj_idx, class->size); area = this_cpu_ptr(&zs_map_area); |