From b8c24c4aef94b1f0daafb450363fef13a1163780 Mon Sep 17 00:00:00 2001 From: Christoph Lameter Date: Wed, 13 Jun 2012 10:24:52 -0500 Subject: [PATCH] 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: Glauber Costa Acked-by: David Rientjes Reviewed-by: Joonsoo Kim Signed-off-by: Christoph Lameter Signed-off-by: Pekka Enberg --- include/linux/mm_types.h | 7 ++- mm/slob.c | 95 ++++++++++++++++------------------------ 2 files changed, 42 insertions(+), 60 deletions(-) diff --git a/include/linux/mm_types.h b/include/linux/mm_types.h index dad95bdd06d7..5922c3452592 100644 --- a/include/linux/mm_types.h +++ b/include/linux/mm_types.h @@ -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 */ diff --git a/mm/slob.c b/mm/slob.c index 8105be42cad1..30862a2d56a9 100644 --- a/mm/slob.c +++ b/mm/slob.c @@ -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);