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slob: Define page struct fields used in mm_types.h

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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: Glauber Costa <glommer@parallels.com>
Acked-by: David Rientjes <rientjes@google.com>
Reviewed-by: Joonsoo Kim <js1304@gmail.com>
Signed-off-by: Christoph Lameter <cl@linux.com>
Signed-off-by: Pekka Enberg <penberg@kernel.org>
This commit is contained in:
Christoph Lameter 2012-06-13 10:24:52 -05:00 committed by Pekka Enberg
parent 23910c50cc
commit b8c24c4aef
2 changed files with 42 additions and 60 deletions
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7
include/linux/mm_types.h
View file

@ -53,7 +53,7 @@ struct page {
struct { struct {
union { union {
pgoff_t index; /* Our offset within mapping. */ pgoff_t index; /* Our offset within mapping. */
void *freelist; /* slub first free object */ void *freelist; /* slub/slob first free object */
}; };
union { union {
@ -81,11 +81,12 @@ struct page {
*/ */
atomic_t _mapcount; atomic_t _mapcount;
struct { struct { /* SLUB */
unsigned inuse:16; unsigned inuse:16;
unsigned objects:15; unsigned objects:15;
unsigned frozen:1; unsigned frozen:1;
}; };
int units; /* SLOB */
}; };
atomic_t _count; /* Usage count, see below. */ atomic_t _count; /* Usage count, see below. */
}; };
@ -107,6 +108,8 @@ struct page {
short int pobjects; short int pobjects;
#endif #endif
}; };
struct list_head list; /* slobs list of pages */
}; };
/* Remainder is not double word aligned */ /* Remainder is not double word aligned */

95
mm/slob.c
View file

@ -91,34 +91,13 @@ struct slob_block {
}; };
typedef struct slob_block slob_t; 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. * 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); reset_page_mapcount(sp);
sp->page.mapping = NULL; 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) * 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. * 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); 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); list_del(&sp->list);
__ClearPageSlobFree((struct page *)sp); __ClearPageSlobFree(sp);
} }
#define SLOB_UNIT sizeof(slob_t) #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. * 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; slob_t *prev, *cur, *aligned = NULL;
int delta = 0, units = SLOB_UNITS(size); 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); slobidx_t avail = slob_units(cur);
if (align) { if (align) {
@ -296,12 +275,12 @@ static void *slob_page_alloc(struct slob_page *sp, size_t size, int align)
if (prev) if (prev)
set_slob(prev, slob_units(prev), next); set_slob(prev, slob_units(prev), next);
else else
sp->free = next; sp->freelist = next;
} else { /* fragment */ } else { /* fragment */
if (prev) if (prev)
set_slob(prev, slob_units(prev), cur + units); set_slob(prev, slob_units(prev), cur + units);
else else
sp->free = cur + units; sp->freelist = cur + units;
set_slob(cur + units, avail - units, next); 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) 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 *prev;
struct list_head *slob_list; struct list_head *slob_list;
slob_t *b = NULL; 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 * If there's a node specification, search for a partial
* page with a matching node id in the freelist. * 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; continue;
#endif #endif
/* Enough room on this page? */ /* 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); spin_lock_irqsave(&slob_lock, flags);
sp->units = SLOB_UNITS(PAGE_SIZE); sp->units = SLOB_UNITS(PAGE_SIZE);
sp->free = b; sp->freelist = b;
INIT_LIST_HEAD(&sp->list); INIT_LIST_HEAD(&sp->list);
set_slob(b, SLOB_UNITS(PAGE_SIZE), b + SLOB_UNITS(PAGE_SIZE)); set_slob(b, SLOB_UNITS(PAGE_SIZE), b + SLOB_UNITS(PAGE_SIZE));
set_slob_page_free(sp, slob_list); 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) static void slob_free(void *block, int size)
{ {
struct slob_page *sp; struct page *sp;
slob_t *prev, *next, *b = (slob_t *)block; slob_t *prev, *next, *b = (slob_t *)block;
slobidx_t units; slobidx_t units;
unsigned long flags; unsigned long flags;
@ -421,7 +400,7 @@ static void slob_free(void *block, int size)
if (!slob_page_free(sp)) { if (!slob_page_free(sp)) {
/* This slob page is about to become partially free. Easy! */ /* This slob page is about to become partially free. Easy! */
sp->units = units; sp->units = units;
sp->free = b; sp->freelist = b;
set_slob(b, units, set_slob(b, units,
(void *)((unsigned long)(b + (void *)((unsigned long)(b +
SLOB_UNITS(PAGE_SIZE)) & PAGE_MASK)); SLOB_UNITS(PAGE_SIZE)) & PAGE_MASK));
@ -441,15 +420,15 @@ static void slob_free(void *block, int size)
*/ */
sp->units += units; sp->units += units;
if (b < sp->free) { if (b < (slob_t *)sp->freelist) {
if (b + units == sp->free) { if (b + units == sp->freelist) {
units += slob_units(sp->free); units += slob_units(sp->freelist);
sp->free = slob_next(sp->free); sp->freelist = slob_next(sp->freelist);
} }
set_slob(b, units, sp->free); set_slob(b, units, sp->freelist);
sp->free = b; sp->freelist = b;
} else { } else {
prev = sp->free; prev = sp->freelist;
next = slob_next(prev); next = slob_next(prev);
while (b > next) { while (b > next) {
prev = next; prev = next;
@ -522,7 +501,7 @@ EXPORT_SYMBOL(__kmalloc_node);
void kfree(const void *block) void kfree(const void *block)
{ {
struct slob_page *sp; struct page *sp;
trace_kfree(_RET_IP_, block); trace_kfree(_RET_IP_, block);
@ -536,14 +515,14 @@ void kfree(const void *block)
unsigned int *m = (unsigned int *)(block - align); unsigned int *m = (unsigned int *)(block - align);
slob_free(m, *m + align); slob_free(m, *m + align);
} else } else
put_page(&sp->page); put_page(sp);
} }
EXPORT_SYMBOL(kfree); EXPORT_SYMBOL(kfree);
/* can't use ksize for kmem_cache_alloc memory, only kmalloc */ /* can't use ksize for kmem_cache_alloc memory, only kmalloc */
size_t ksize(const void *block) size_t ksize(const void *block)
{ {
struct slob_page *sp; struct page *sp;
BUG_ON(!block); BUG_ON(!block);
if (unlikely(block == ZERO_SIZE_PTR)) if (unlikely(block == ZERO_SIZE_PTR))
@ -555,7 +534,7 @@ size_t ksize(const void *block)
unsigned int *m = (unsigned int *)(block - align); unsigned int *m = (unsigned int *)(block - align);
return SLOB_UNITS(*m) * SLOB_UNIT; return SLOB_UNITS(*m) * SLOB_UNIT;
} else } else
return sp->page.private; return sp->private;
} }
EXPORT_SYMBOL(ksize); EXPORT_SYMBOL(ksize);