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Commit 66cdef66 authored by Ganesh Mahendran's avatar Ganesh Mahendran Committed by Linus Torvalds
Browse files

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: default avatarGanesh Mahendran <opensource.ganesh@gmail.com>
Cc: Nitin Gupta <ngupta@vflare.org>
Acked-by: default avatarMinchan Kim <minchan@kernel.org>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 136f49b9

mm/zsmalloc.c

+187 −187
Original line number Diff line number Diff line
@@ -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;



	pool = kzalloc(sizeof(*pool), GFP_KERNEL);

	if (!pool)

		return NULL;



	pool->size_class = kcalloc(zs_size_classes, sizeof(struct size_class *),

			GFP_KERNEL);

	if (!pool->size_class) {

		kfree(pool);

		return NULL;

	}

	struct page *page;

	unsigned long obj_idx, off;



	/*

	 * 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;

	unsigned int class_idx;

	enum fullness_group fg;

	struct size_class *class;

	struct mapping_area *area;

	struct page *pages[2];



		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);

	BUG_ON(!handle);



	/*

		 * 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.

	 * 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.

	 */

		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);

	}

EXPORT_SYMBOL_GPL(zs_destroy_pool);

	put_cpu_var(zs_map_area);

}

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;

	pool = kzalloc(sizeof(*pool), GFP_KERNEL);

	if (!pool)

		return NULL;



	pool->size_class = kcalloc(zs_size_classes, sizeof(struct size_class *),

			GFP_KERNEL);

	if (!pool->size_class) {

		kfree(pool);

		return NULL;

	}



	/*

	 * 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 mapping_area *area;

	struct page *pages[2];



	BUG_ON(!handle);

		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);



		/*

	 * 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.

		 * 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.

		 */

	BUG_ON(in_interrupt());

		if (prev_class) {

			if (can_merge(prev_class, size, pages_per_zspage)) {

				pool->size_class[i] = prev_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);

		class = kzalloc(sizeof(struct size_class), GFP_KERNEL);

		if (!class)

			goto err;



	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;

		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);