From: Ganesh Mahendran Date: Fri, 19 Dec 2014 00:17:40 +0000 (-0800) Subject: mm/zsmalloc: adjust order of functions X-Git-Tag: v3.19-rc1~31^2~1 X-Git-Url: http://git.samba.org/samba.git/?p=sfrench%2Fcifs-2.6.git;a=commitdiff_plain;h=66cdef663cd7a97aff6bbbf41a81a0205dc81ba2 mm/zsmalloc: adjust order of functions Currently functions in zsmalloc.c does not arranged in a readable and reasonable sequence. With the more and more functions added, we may meet below inconvenience. For example: Current functions: void zs_init() { } static void get_maxobj_per_zspage() { } Then I want to add a func_1() which is called from zs_init(), and this new added function func_1() will used get_maxobj_per_zspage() which is defined below zs_init(). void func_1() { get_maxobj_per_zspage() } void zs_init() { func_1() } static void get_maxobj_per_zspage() { } This will cause compiling issue. So we must add a declaration: static void get_maxobj_per_zspage(); before func_1() if we do not put get_maxobj_per_zspage() before func_1(). In addition, puting module_[init|exit] functions at the bottom of the file conforms to our habit. So, this patch ajusts function sequence as: /* helper functions */ ... obj_location_to_handle() ... /* Some exported functions */ ... zs_map_object() zs_unmap_object() zs_malloc() zs_free() zs_init() zs_exit() Signed-off-by: Ganesh Mahendran Cc: Nitin Gupta Acked-by: Minchan Kim Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- diff --git a/mm/zsmalloc.c b/mm/zsmalloc.c index 4d0a063145ec..b72403927aa4 100644 --- a/mm/zsmalloc.c +++ b/mm/zsmalloc.c @@ -884,19 +884,6 @@ static struct notifier_block zs_cpu_nb = { .notifier_call = zs_cpu_notifier }; -static void zs_unregister_cpu_notifier(void) -{ - int cpu; - - cpu_notifier_register_begin(); - - for_each_online_cpu(cpu) - zs_cpu_notifier(NULL, CPU_DEAD, (void *)(long)cpu); - __unregister_cpu_notifier(&zs_cpu_nb); - - cpu_notifier_register_done(); -} - static int zs_register_cpu_notifier(void) { int cpu, uninitialized_var(ret); @@ -914,40 +901,28 @@ static int zs_register_cpu_notifier(void) return notifier_to_errno(ret); } -static void init_zs_size_classes(void) +static void zs_unregister_cpu_notifier(void) { - int nr; + int cpu; - nr = (ZS_MAX_ALLOC_SIZE - ZS_MIN_ALLOC_SIZE) / ZS_SIZE_CLASS_DELTA + 1; - if ((ZS_MAX_ALLOC_SIZE - ZS_MIN_ALLOC_SIZE) % ZS_SIZE_CLASS_DELTA) - nr += 1; + cpu_notifier_register_begin(); - zs_size_classes = nr; -} + for_each_online_cpu(cpu) + zs_cpu_notifier(NULL, CPU_DEAD, (void *)(long)cpu); + __unregister_cpu_notifier(&zs_cpu_nb); -static void __exit zs_exit(void) -{ -#ifdef CONFIG_ZPOOL - zpool_unregister_driver(&zs_zpool_driver); -#endif - zs_unregister_cpu_notifier(); + cpu_notifier_register_done(); } -static int __init zs_init(void) +static void init_zs_size_classes(void) { - int ret = zs_register_cpu_notifier(); - - if (ret) { - zs_unregister_cpu_notifier(); - return ret; - } + int nr; - init_zs_size_classes(); + nr = (ZS_MAX_ALLOC_SIZE - ZS_MIN_ALLOC_SIZE) / ZS_SIZE_CLASS_DELTA + 1; + if ((ZS_MAX_ALLOC_SIZE - ZS_MIN_ALLOC_SIZE) % ZS_SIZE_CLASS_DELTA) + nr += 1; -#ifdef CONFIG_ZPOOL - zpool_register_driver(&zs_zpool_driver); -#endif - return 0; + zs_size_classes = nr; } static unsigned int get_maxobj_per_zspage(int size, int pages_per_zspage) @@ -967,113 +942,101 @@ static bool can_merge(struct size_class *prev, int size, int pages_per_zspage) return true; } +unsigned long zs_get_total_pages(struct zs_pool *pool) +{ + return atomic_long_read(&pool->pages_allocated); +} +EXPORT_SYMBOL_GPL(zs_get_total_pages); + /** - * zs_create_pool - Creates an allocation pool to work from. - * @flags: allocation flags used to allocate pool metadata + * zs_map_object - get address of allocated object from handle. + * @pool: pool from which the object was allocated + * @handle: handle returned from zs_malloc * - * This function must be called before anything when using - * the zsmalloc allocator. + * Before using an object allocated from zs_malloc, it must be mapped using + * this function. When done with the object, it must be unmapped using + * zs_unmap_object. * - * On success, a pointer to the newly created pool is returned, - * otherwise NULL. + * Only one object can be mapped per cpu at a time. There is no protection + * against nested mappings. + * + * This function returns with preemption and page faults disabled. */ -struct zs_pool *zs_create_pool(gfp_t flags) +void *zs_map_object(struct zs_pool *pool, unsigned long handle, + enum zs_mapmode mm) { - int i; - struct zs_pool *pool; - struct size_class *prev_class = NULL; + struct page *page; + unsigned long obj_idx, off; - pool = kzalloc(sizeof(*pool), GFP_KERNEL); - if (!pool) - return NULL; + unsigned int class_idx; + enum fullness_group fg; + struct size_class *class; + struct mapping_area *area; + struct page *pages[2]; - pool->size_class = kcalloc(zs_size_classes, sizeof(struct size_class *), - GFP_KERNEL); - if (!pool->size_class) { - kfree(pool); - return NULL; - } + BUG_ON(!handle); /* - * Iterate reversly, because, size of size_class that we want to use - * for merging should be larger or equal to current size. + * Because we use per-cpu mapping areas shared among the + * pools/users, we can't allow mapping in interrupt context + * because it can corrupt another users mappings. */ - for (i = zs_size_classes - 1; i >= 0; i--) { - int size; - int pages_per_zspage; - struct size_class *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 (prev_class) { - 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; + BUG_ON(in_interrupt()); - class->size = size; - class->index = i; - class->pages_per_zspage = pages_per_zspage; - spin_lock_init(&class->lock); - pool->size_class[i] = class; + obj_handle_to_location(handle, &page, &obj_idx); + get_zspage_mapping(get_first_page(page), &class_idx, &fg); + class = pool->size_class[class_idx]; + off = obj_idx_to_offset(page, obj_idx, class->size); - prev_class = class; + area = &get_cpu_var(zs_map_area); + area->vm_mm = mm; + if (off + class->size <= PAGE_SIZE) { + /* this object is contained entirely within a page */ + area->vm_addr = kmap_atomic(page); + return area->vm_addr + off; } - pool->flags = flags; - - return pool; + /* this object spans two pages */ + pages[0] = page; + pages[1] = get_next_page(page); + BUG_ON(!pages[1]); -err: - zs_destroy_pool(pool); - return NULL; + return __zs_map_object(area, pages, off, class->size); } -EXPORT_SYMBOL_GPL(zs_create_pool); +EXPORT_SYMBOL_GPL(zs_map_object); -void zs_destroy_pool(struct zs_pool *pool) +void zs_unmap_object(struct zs_pool *pool, unsigned long handle) { - int i; + struct page *page; + unsigned long obj_idx, off; - for (i = 0; i < zs_size_classes; i++) { - int fg; - struct size_class *class = pool->size_class[i]; + unsigned int class_idx; + enum fullness_group fg; + struct size_class *class; + struct mapping_area *area; - if (!class) - continue; + BUG_ON(!handle); - if (class->index != i) - continue; + obj_handle_to_location(handle, &page, &obj_idx); + get_zspage_mapping(get_first_page(page), &class_idx, &fg); + class = pool->size_class[class_idx]; + off = obj_idx_to_offset(page, obj_idx, class->size); - for (fg = 0; fg < _ZS_NR_FULLNESS_GROUPS; fg++) { - if (class->fullness_list[fg]) { - pr_info("Freeing non-empty class with size %db, fullness group %d\n", - class->size, fg); - } - } - kfree(class); - } + area = this_cpu_ptr(&zs_map_area); + if (off + class->size <= PAGE_SIZE) + kunmap_atomic(area->vm_addr); + else { + struct page *pages[2]; - kfree(pool->size_class); - kfree(pool); + pages[0] = page; + pages[1] = get_next_page(page); + BUG_ON(!pages[1]); + + __zs_unmap_object(area, pages, off, class->size); + } + put_cpu_var(zs_map_area); } -EXPORT_SYMBOL_GPL(zs_destroy_pool); +EXPORT_SYMBOL_GPL(zs_unmap_object); /** * zs_malloc - Allocate block of given size from pool. @@ -1176,100 +1139,137 @@ void zs_free(struct zs_pool *pool, unsigned long obj) EXPORT_SYMBOL_GPL(zs_free); /** - * zs_map_object - get address of allocated object from handle. - * @pool: pool from which the object was allocated - * @handle: handle returned from zs_malloc - * - * Before using an object allocated from zs_malloc, it must be mapped using - * this function. When done with the object, it must be unmapped using - * zs_unmap_object. + * zs_create_pool - Creates an allocation pool to work from. + * @flags: allocation flags used to allocate pool metadata * - * Only one object can be mapped per cpu at a time. There is no protection - * against nested mappings. + * This function must be called before anything when using + * the zsmalloc allocator. * - * This function returns with preemption and page faults disabled. + * On success, a pointer to the newly created pool is returned, + * otherwise NULL. */ -void *zs_map_object(struct zs_pool *pool, unsigned long handle, - enum zs_mapmode mm) +struct zs_pool *zs_create_pool(gfp_t flags) { - struct page *page; - unsigned long obj_idx, off; + int i; + struct zs_pool *pool; + struct size_class *prev_class = NULL; - unsigned int class_idx; - enum fullness_group fg; - struct size_class *class; - struct mapping_area *area; - struct page *pages[2]; + pool = kzalloc(sizeof(*pool), GFP_KERNEL); + if (!pool) + return NULL; - BUG_ON(!handle); + pool->size_class = kcalloc(zs_size_classes, sizeof(struct size_class *), + GFP_KERNEL); + if (!pool->size_class) { + kfree(pool); + return NULL; + } /* - * Because we use per-cpu mapping areas shared among the - * pools/users, we can't allow mapping in interrupt context - * because it can corrupt another users mappings. + * Iterate reversly, because, size of size_class that we want to use + * for merging should be larger or equal to current size. */ - BUG_ON(in_interrupt()); + for (i = zs_size_classes - 1; i >= 0; i--) { + int size; + int pages_per_zspage; + struct size_class *class; - obj_handle_to_location(handle, &page, &obj_idx); - get_zspage_mapping(get_first_page(page), &class_idx, &fg); - class = pool->size_class[class_idx]; - off = obj_idx_to_offset(page, obj_idx, class->size); + 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); - area = &get_cpu_var(zs_map_area); - area->vm_mm = mm; - if (off + class->size <= PAGE_SIZE) { - /* this object is contained entirely within a page */ - area->vm_addr = kmap_atomic(page); - return area->vm_addr + off; + /* + * 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 (prev_class) { + 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->size = size; + class->index = i; + class->pages_per_zspage = pages_per_zspage; + spin_lock_init(&class->lock); + pool->size_class[i] = class; + + prev_class = class; } - /* this object spans two pages */ - pages[0] = page; - pages[1] = get_next_page(page); - BUG_ON(!pages[1]); + pool->flags = flags; - return __zs_map_object(area, pages, off, class->size); + return pool; + +err: + zs_destroy_pool(pool); + return NULL; } -EXPORT_SYMBOL_GPL(zs_map_object); +EXPORT_SYMBOL_GPL(zs_create_pool); -void zs_unmap_object(struct zs_pool *pool, unsigned long handle) +void zs_destroy_pool(struct zs_pool *pool) { - struct page *page; - unsigned long obj_idx, off; + int i; - unsigned int class_idx; - enum fullness_group fg; - struct size_class *class; - struct mapping_area *area; + for (i = 0; i < zs_size_classes; i++) { + int fg; + struct size_class *class = pool->size_class[i]; - BUG_ON(!handle); + if (!class) + continue; - obj_handle_to_location(handle, &page, &obj_idx); - get_zspage_mapping(get_first_page(page), &class_idx, &fg); - class = pool->size_class[class_idx]; - off = obj_idx_to_offset(page, obj_idx, class->size); + if (class->index != i) + continue; - area = this_cpu_ptr(&zs_map_area); - if (off + class->size <= PAGE_SIZE) - kunmap_atomic(area->vm_addr); - else { - struct page *pages[2]; + for (fg = 0; fg < _ZS_NR_FULLNESS_GROUPS; fg++) { + if (class->fullness_list[fg]) { + pr_info("Freeing non-empty class with size %db, fullness group %d\n", + class->size, fg); + } + } + kfree(class); + } - pages[0] = page; - pages[1] = get_next_page(page); - BUG_ON(!pages[1]); + kfree(pool->size_class); + kfree(pool); +} +EXPORT_SYMBOL_GPL(zs_destroy_pool); - __zs_unmap_object(area, pages, off, class->size); +static int __init zs_init(void) +{ + int ret = zs_register_cpu_notifier(); + + if (ret) { + zs_unregister_cpu_notifier(); + return ret; } - put_cpu_var(zs_map_area); + + init_zs_size_classes(); + +#ifdef CONFIG_ZPOOL + zpool_register_driver(&zs_zpool_driver); +#endif + return 0; } -EXPORT_SYMBOL_GPL(zs_unmap_object); -unsigned long zs_get_total_pages(struct zs_pool *pool) +static void __exit zs_exit(void) { - return atomic_long_read(&pool->pages_allocated); +#ifdef CONFIG_ZPOOL + zpool_unregister_driver(&zs_zpool_driver); +#endif + zs_unregister_cpu_notifier(); } -EXPORT_SYMBOL_GPL(zs_get_total_pages); module_init(zs_init); module_exit(zs_exit);