Commit b8c24c4a authored by Christoph Lameter's avatar Christoph Lameter Committed by Pekka Enberg
Browse files

slob: Define page struct fields used in mm_types.h 



Define the fields used by slob in mm_types.h and use struct page instead
of struct slob_page in slob. This cleans up numerous of typecasts in slob.c and
makes readers aware of slob's use of page struct fields.

[Also cleans up some bitrot in slob.c. The page struct field layout
in slob.c is an old layout and does not match the one in mm_types.h]

Reviewed-by: default avatarGlauber Costa <glommer@parallels.com>
Acked-by: default avatarDavid Rientjes <rientjes@google.com>
Reviewed-by: default avatarJoonsoo Kim <js1304@gmail.com>
Signed-off-by: default avatarChristoph Lameter <cl@linux.com>
Signed-off-by: default avatarPekka Enberg <penberg@kernel.org>
parent 23910c50

include/linux/mm_types.h

+5 −2
Original line number Diff line number Diff line
@@ -53,7 +53,7 @@ struct page { 
	struct {

		union {

			pgoff_t index;		/* Our offset within mapping. */

			void *freelist;		/* slub first free object */

			void *freelist;		/* slub/slob first free object */

		};



		union {
@@ -81,11 +81,12 @@ struct page { 
					 */

					atomic_t _mapcount;



					struct {

					struct { /* SLUB */

						unsigned inuse:16;

						unsigned objects:15;

						unsigned frozen:1;

					};

					int units;	/* SLOB */

				};

				atomic_t _count;		/* Usage count, see below. */

			};
@@ -107,6 +108,8 @@ struct page { 
			short int pobjects;

#endif

		};



		struct list_head list;	/* slobs list of pages */

	};



	/* Remainder is not double word aligned */

mm/slob.c

+37 −58
Original line number Diff line number Diff line
@@ -91,34 +91,13 @@ struct slob_block { 
};

typedef struct slob_block slob_t;



/*

 * We use struct page fields to manage some slob allocation aspects,

 * however to avoid the horrible mess in include/linux/mm_types.h, we'll

 * just define our own struct page type variant here.

 */

struct slob_page {

	union {

		struct {

			unsigned long flags;	/* mandatory */

			atomic_t _count;	/* mandatory */

			slobidx_t units;	/* free units left in page */

			unsigned long pad[2];

			slob_t *free;		/* first free slob_t in page */

			struct list_head list;	/* linked list of free pages */

		};

		struct page page;

	};

};

static inline void struct_slob_page_wrong_size(void)

{ BUILD_BUG_ON(sizeof(struct slob_page) != sizeof(struct page)); }



/*

 * free_slob_page: call before a slob_page is returned to the page allocator.

 */

static inline void free_slob_page(struct slob_page *sp)

static inline void free_slob_page(struct page *sp)

{

	reset_page_mapcount(&sp->page);

	sp->page.mapping = NULL;

	reset_page_mapcount(sp);

	sp->mapping = NULL;

}



/*
@@ -133,44 +112,44 @@ static LIST_HEAD(free_slob_large); 
/*

 * is_slob_page: True for all slob pages (false for bigblock pages)

 */

static inline int is_slob_page(struct slob_page *sp)

static inline int is_slob_page(struct page *sp)

{

	return PageSlab((struct page *)sp);

	return PageSlab(sp);

}



static inline void set_slob_page(struct slob_page *sp)

static inline void set_slob_page(struct page *sp)

{

	__SetPageSlab((struct page *)sp);

	__SetPageSlab(sp);

}



static inline void clear_slob_page(struct slob_page *sp)

static inline void clear_slob_page(struct page *sp)

{

	__ClearPageSlab((struct page *)sp);

	__ClearPageSlab(sp);

}



static inline struct slob_page *slob_page(const void *addr)

static inline struct page *slob_page(const void *addr)

{

	return (struct slob_page *)virt_to_page(addr);

	return virt_to_page(addr);

}



/*

 * slob_page_free: true for pages on free_slob_pages list.

 */

static inline int slob_page_free(struct slob_page *sp)

static inline int slob_page_free(struct page *sp)

{

	return PageSlobFree((struct page *)sp);

	return PageSlobFree(sp);

}



static void set_slob_page_free(struct slob_page *sp, struct list_head *list)

static void set_slob_page_free(struct page *sp, struct list_head *list)

{

	list_add(&sp->list, list);

	__SetPageSlobFree((struct page *)sp);

	__SetPageSlobFree(sp);

}



static inline void clear_slob_page_free(struct slob_page *sp)

static inline void clear_slob_page_free(struct page *sp)

{

	list_del(&sp->list);

	__ClearPageSlobFree((struct page *)sp);

	__ClearPageSlobFree(sp);

}



#define SLOB_UNIT sizeof(slob_t)
@@ -267,12 +246,12 @@ static void slob_free_pages(void *b, int order) 
/*

 * Allocate a slob block within a given slob_page sp.

 */

static void *slob_page_alloc(struct slob_page *sp, size_t size, int align)

static void *slob_page_alloc(struct page *sp, size_t size, int align)

{

	slob_t *prev, *cur, *aligned = NULL;

	int delta = 0, units = SLOB_UNITS(size);



	for (prev = NULL, cur = sp->free; ; prev = cur, cur = slob_next(cur)) {

	for (prev = NULL, cur = sp->freelist; ; prev = cur, cur = slob_next(cur)) {

		slobidx_t avail = slob_units(cur);



		if (align) {
@@ -296,12 +275,12 @@ static void *slob_page_alloc(struct slob_page *sp, size_t size, int align) 
				if (prev)

					set_slob(prev, slob_units(prev), next);

				else

					sp->free = next;

					sp->freelist = next;

			} else { /* fragment */

				if (prev)

					set_slob(prev, slob_units(prev), cur + units);

				else

					sp->free = cur + units;

					sp->freelist = cur + units;

				set_slob(cur + units, avail - units, next);

			}
@@ -320,7 +299,7 @@ static void *slob_page_alloc(struct slob_page *sp, size_t size, int align) 
 */

static void *slob_alloc(size_t size, gfp_t gfp, int align, int node)

{

	struct slob_page *sp;

	struct page *sp;

	struct list_head *prev;

	struct list_head *slob_list;

	slob_t *b = NULL;
@@ -341,7 +320,7 @@ static void *slob_alloc(size_t size, gfp_t gfp, int align, int node) 
		 * If there's a node specification, search for a partial

		 * page with a matching node id in the freelist.

		 */

		if (node != -1 && page_to_nid(&sp->page) != node)

		if (node != -1 && page_to_nid(sp) != node)

			continue;

#endif

		/* Enough room on this page? */
@@ -374,7 +353,7 @@ static void *slob_alloc(size_t size, gfp_t gfp, int align, int node) 


		spin_lock_irqsave(&slob_lock, flags);

		sp->units = SLOB_UNITS(PAGE_SIZE);

		sp->free = b;

		sp->freelist = b;

		INIT_LIST_HEAD(&sp->list);

		set_slob(b, SLOB_UNITS(PAGE_SIZE), b + SLOB_UNITS(PAGE_SIZE));

		set_slob_page_free(sp, slob_list);
@@ -392,7 +371,7 @@ static void *slob_alloc(size_t size, gfp_t gfp, int align, int node) 
 */

static void slob_free(void *block, int size)

{

	struct slob_page *sp;

	struct page *sp;

	slob_t *prev, *next, *b = (slob_t *)block;

	slobidx_t units;

	unsigned long flags;
@@ -421,7 +400,7 @@ static void slob_free(void *block, int size) 
	if (!slob_page_free(sp)) {

		/* This slob page is about to become partially free. Easy! */

		sp->units = units;

		sp->free = b;

		sp->freelist = b;

		set_slob(b, units,

			(void *)((unsigned long)(b +

					SLOB_UNITS(PAGE_SIZE)) & PAGE_MASK));
@@ -441,15 +420,15 @@ static void slob_free(void *block, int size) 
	 */

	sp->units += units;



	if (b < sp->free) {

		if (b + units == sp->free) {

			units += slob_units(sp->free);

			sp->free = slob_next(sp->free);

	if (b < (slob_t *)sp->freelist) {

		if (b + units == sp->freelist) {

			units += slob_units(sp->freelist);

			sp->freelist = slob_next(sp->freelist);

		}

		set_slob(b, units, sp->free);

		sp->free = b;

		set_slob(b, units, sp->freelist);

		sp->freelist = b;

	} else {

		prev = sp->free;

		prev = sp->freelist;

		next = slob_next(prev);

		while (b > next) {

			prev = next;
@@ -522,7 +501,7 @@ EXPORT_SYMBOL(__kmalloc_node); 


void kfree(const void *block)

{

	struct slob_page *sp;

	struct page *sp;



	trace_kfree(_RET_IP_, block);
@@ -536,14 +515,14 @@ void kfree(const void *block) 
		unsigned int *m = (unsigned int *)(block - align);

		slob_free(m, *m + align);

	} else

		put_page(&sp->page);

		put_page(sp);

}

EXPORT_SYMBOL(kfree);



/* can't use ksize for kmem_cache_alloc memory, only kmalloc */

size_t ksize(const void *block)

{

	struct slob_page *sp;

	struct page *sp;



	BUG_ON(!block);

	if (unlikely(block == ZERO_SIZE_PTR))
@@ -555,7 +534,7 @@ size_t ksize(const void *block) 
		unsigned int *m = (unsigned int *)(block - align);

		return SLOB_UNITS(*m) * SLOB_UNIT;

	} else

		return sp->page.private;

		return sp->private;

}

EXPORT_SYMBOL(ksize);

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