From 423c929cbbecc60e9c407f9048e58f5422f7995d Mon Sep 17 00:00:00 2001 From: Joonsoo Kim Date: Thu, 9 Oct 2014 15:26:22 -0700 Subject: mm/slab_common: commonize slab merge logic Slab merge is good feature to reduce fragmentation. Now, it is only applied to SLUB, but, it would be good to apply it to SLAB. This patch is preparation step to apply slab merge to SLAB by commonizing slab merge logic. Signed-off-by: Joonsoo Kim Cc: Randy Dunlap Cc: Christoph Lameter Cc: Pekka Enberg Cc: David Rientjes Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- mm/slab.h | 15 ++++++++++ mm/slab_common.c | 91 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++ mm/slub.c | 91 ++------------------------------------------------------ 3 files changed, 108 insertions(+), 89 deletions(-) (limited to 'mm') diff --git a/mm/slab.h b/mm/slab.h index 6599f2084e80..c44d28b60609 100644 --- a/mm/slab.h +++ b/mm/slab.h @@ -88,15 +88,30 @@ extern void create_boot_cache(struct kmem_cache *, const char *name, size_t size, unsigned long flags); struct mem_cgroup; + +int slab_unmergeable(struct kmem_cache *s); +struct kmem_cache *find_mergeable(size_t size, size_t align, + unsigned long flags, const char *name, void (*ctor)(void *)); #ifdef CONFIG_SLUB struct kmem_cache * __kmem_cache_alias(const char *name, size_t size, size_t align, unsigned long flags, void (*ctor)(void *)); + +unsigned long kmem_cache_flags(unsigned long object_size, + unsigned long flags, const char *name, + void (*ctor)(void *)); #else static inline struct kmem_cache * __kmem_cache_alias(const char *name, size_t size, size_t align, unsigned long flags, void (*ctor)(void *)) { return NULL; } + +static inline unsigned long kmem_cache_flags(unsigned long object_size, + unsigned long flags, const char *name, + void (*ctor)(void *)) +{ + return flags; +} #endif diff --git a/mm/slab_common.c b/mm/slab_common.c index d7d8ffd0c306..f206cb10a544 100644 --- a/mm/slab_common.c +++ b/mm/slab_common.c @@ -30,6 +30,34 @@ LIST_HEAD(slab_caches); DEFINE_MUTEX(slab_mutex); struct kmem_cache *kmem_cache; +/* + * Set of flags that will prevent slab merging + */ +#define SLAB_NEVER_MERGE (SLAB_RED_ZONE | SLAB_POISON | SLAB_STORE_USER | \ + SLAB_TRACE | SLAB_DESTROY_BY_RCU | SLAB_NOLEAKTRACE | \ + SLAB_FAILSLAB) + +#define SLAB_MERGE_SAME (SLAB_DEBUG_FREE | SLAB_RECLAIM_ACCOUNT | \ + SLAB_CACHE_DMA | SLAB_NOTRACK) + +/* + * Merge control. If this is set then no merging of slab caches will occur. + * (Could be removed. This was introduced to pacify the merge skeptics.) + */ +static int slab_nomerge; + +static int __init setup_slab_nomerge(char *str) +{ + slab_nomerge = 1; + return 1; +} + +#ifdef CONFIG_SLUB +__setup_param("slub_nomerge", slub_nomerge, setup_slab_nomerge, 0); +#endif + +__setup("slab_nomerge", setup_slab_nomerge); + /* * Determine the size of a slab object */ @@ -115,6 +143,69 @@ out: } #endif +/* + * Find a mergeable slab cache + */ +int slab_unmergeable(struct kmem_cache *s) +{ + if (slab_nomerge || (s->flags & SLAB_NEVER_MERGE)) + return 1; + + if (!is_root_cache(s)) + return 1; + + if (s->ctor) + return 1; + + /* + * We may have set a slab to be unmergeable during bootstrap. + */ + if (s->refcount < 0) + return 1; + + return 0; +} + +struct kmem_cache *find_mergeable(size_t size, size_t align, + unsigned long flags, const char *name, void (*ctor)(void *)) +{ + struct kmem_cache *s; + + if (slab_nomerge || (flags & SLAB_NEVER_MERGE)) + return NULL; + + if (ctor) + return NULL; + + size = ALIGN(size, sizeof(void *)); + align = calculate_alignment(flags, align, size); + size = ALIGN(size, align); + flags = kmem_cache_flags(size, flags, name, NULL); + + list_for_each_entry(s, &slab_caches, list) { + if (slab_unmergeable(s)) + continue; + + if (size > s->size) + continue; + + if ((flags & SLAB_MERGE_SAME) != (s->flags & SLAB_MERGE_SAME)) + continue; + /* + * Check if alignment is compatible. + * Courtesy of Adrian Drzewiecki + */ + if ((s->size & ~(align - 1)) != s->size) + continue; + + if (s->size - size >= sizeof(void *)) + continue; + + return s; + } + return NULL; +} + /* * Figure out what the alignment of the objects will be given a set of * flags, a user specified alignment and the size of the objects. diff --git a/mm/slub.c b/mm/slub.c index 1050d7db5734..ae7b9f1ad394 100644 --- a/mm/slub.c +++ b/mm/slub.c @@ -169,16 +169,6 @@ static inline bool kmem_cache_has_cpu_partial(struct kmem_cache *s) */ #define DEBUG_METADATA_FLAGS (SLAB_RED_ZONE | SLAB_POISON | SLAB_STORE_USER) -/* - * Set of flags that will prevent slab merging - */ -#define SLUB_NEVER_MERGE (SLAB_RED_ZONE | SLAB_POISON | SLAB_STORE_USER | \ - SLAB_TRACE | SLAB_DESTROY_BY_RCU | SLAB_NOLEAKTRACE | \ - SLAB_FAILSLAB) - -#define SLUB_MERGE_SAME (SLAB_DEBUG_FREE | SLAB_RECLAIM_ACCOUNT | \ - SLAB_CACHE_DMA | SLAB_NOTRACK) - #define OO_SHIFT 16 #define OO_MASK ((1 << OO_SHIFT) - 1) #define MAX_OBJS_PER_PAGE 32767 /* since page.objects is u15 */ @@ -1176,7 +1166,7 @@ out: __setup("slub_debug", setup_slub_debug); -static unsigned long kmem_cache_flags(unsigned long object_size, +unsigned long kmem_cache_flags(unsigned long object_size, unsigned long flags, const char *name, void (*ctor)(void *)) { @@ -1208,7 +1198,7 @@ static inline void add_full(struct kmem_cache *s, struct kmem_cache_node *n, struct page *page) {} static inline void remove_full(struct kmem_cache *s, struct kmem_cache_node *n, struct page *page) {} -static inline unsigned long kmem_cache_flags(unsigned long object_size, +unsigned long kmem_cache_flags(unsigned long object_size, unsigned long flags, const char *name, void (*ctor)(void *)) { @@ -2718,12 +2708,6 @@ static int slub_min_order; static int slub_max_order = PAGE_ALLOC_COSTLY_ORDER; static int slub_min_objects; -/* - * Merge control. If this is set then no merging of slab caches will occur. - * (Could be removed. This was introduced to pacify the merge skeptics.) - */ -static int slub_nomerge; - /* * Calculate the order of allocation given an slab object size. * @@ -3252,14 +3236,6 @@ static int __init setup_slub_min_objects(char *str) __setup("slub_min_objects=", setup_slub_min_objects); -static int __init setup_slub_nomerge(char *str) -{ - slub_nomerge = 1; - return 1; -} - -__setup("slub_nomerge", setup_slub_nomerge); - void *__kmalloc(size_t size, gfp_t flags) { struct kmem_cache *s; @@ -3637,69 +3613,6 @@ void __init kmem_cache_init_late(void) { } -/* - * Find a mergeable slab cache - */ -static int slab_unmergeable(struct kmem_cache *s) -{ - if (slub_nomerge || (s->flags & SLUB_NEVER_MERGE)) - return 1; - - if (!is_root_cache(s)) - return 1; - - if (s->ctor) - return 1; - - /* - * We may have set a slab to be unmergeable during bootstrap. - */ - if (s->refcount < 0) - return 1; - - return 0; -} - -static struct kmem_cache *find_mergeable(size_t size, size_t align, - unsigned long flags, const char *name, void (*ctor)(void *)) -{ - struct kmem_cache *s; - - if (slub_nomerge || (flags & SLUB_NEVER_MERGE)) - return NULL; - - if (ctor) - return NULL; - - size = ALIGN(size, sizeof(void *)); - align = calculate_alignment(flags, align, size); - size = ALIGN(size, align); - flags = kmem_cache_flags(size, flags, name, NULL); - - list_for_each_entry(s, &slab_caches, list) { - if (slab_unmergeable(s)) - continue; - - if (size > s->size) - continue; - - if ((flags & SLUB_MERGE_SAME) != (s->flags & SLUB_MERGE_SAME)) - continue; - /* - * Check if alignment is compatible. - * Courtesy of Adrian Drzewiecki - */ - if ((s->size & ~(align - 1)) != s->size) - continue; - - if (s->size - size >= sizeof(void *)) - continue; - - return s; - } - return NULL; -} - struct kmem_cache * __kmem_cache_alias(const char *name, size_t size, size_t align, unsigned long flags, void (*ctor)(void *)) -- cgit v1.2.3