From: Christoph Lameter Date: Wed, 9 May 2007 09:32:44 +0000 (-0700) Subject: SLUB: add CONFIG_SLUB_DEBUG X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=41ecc55b8a8ca618e6d490982c7ce45d230d4399;p=GitHub%2FLineageOS%2Fandroid_kernel_motorola_exynos9610.git SLUB: add CONFIG_SLUB_DEBUG CONFIG_SLUB_DEBUG can be used to switch off the debugging and sysfs components of SLUB. Thus SLUB will be able to replace SLOB. SLUB can arrange objects in a denser way than SLOB and the code size should be minimal without debugging and sysfs support. Note that CONFIG_SLUB_DEBUG is materially different from CONFIG_SLAB_DEBUG. CONFIG_SLAB_DEBUG is used to enable slab debugging in SLAB. SLUB enables debugging via a boot parameter. SLUB debug code should always be present. CONFIG_SLUB_DEBUG can be modified in the embedded config section. Signed-off-by: Christoph Lameter Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- diff --git a/init/Kconfig b/init/Kconfig index d0edf42f4dba..da6a91c4a051 100644 --- a/init/Kconfig +++ b/init/Kconfig @@ -504,6 +504,15 @@ config VM_EVENT_COUNTERS on EMBEDDED systems. /proc/vmstat will only show page counts if VM event counters are disabled. +config SLUB_DEBUG + default y + bool "Enable SLUB debugging support" if EMBEDDED + help + SLUB has extensive debug support features. Disabling these can + result in significant savings in code size. This also disables + SLUB sysfs support. /sys/slab will not exist and there will be + no support for cache validation etc. + choice prompt "Choose SLAB allocator" default SLAB diff --git a/mm/slub.c b/mm/slub.c index b9e05366afda..3e614c1901b7 100644 --- a/mm/slub.c +++ b/mm/slub.c @@ -89,17 +89,25 @@ static inline int SlabDebug(struct page *page) { +#ifdef CONFIG_SLUB_DEBUG return PageError(page); +#else + return 0; +#endif } static inline void SetSlabDebug(struct page *page) { +#ifdef CONFIG_SLUB_DEBUG SetPageError(page); +#endif } static inline void ClearSlabDebug(struct page *page) { +#ifdef CONFIG_SLUB_DEBUG ClearPageError(page); +#endif } /* @@ -207,7 +215,7 @@ struct track { enum track_item { TRACK_ALLOC, TRACK_FREE }; -#ifdef CONFIG_SYSFS +#if defined(CONFIG_SYSFS) && defined(CONFIG_SLUB_DEBUG) static int sysfs_slab_add(struct kmem_cache *); static int sysfs_slab_alias(struct kmem_cache *, const char *); static void sysfs_slab_remove(struct kmem_cache *); @@ -284,6 +292,14 @@ static inline int slab_index(void *p, struct kmem_cache *s, void *addr) return (p - addr) / s->size; } +#ifdef CONFIG_SLUB_DEBUG +/* + * Debug settings: + */ +static int slub_debug; + +static char *slub_debug_slabs; + /* * Object debugging */ @@ -821,6 +837,97 @@ static void trace(struct kmem_cache *s, struct page *page, void *object, int all } } +static int __init setup_slub_debug(char *str) +{ + if (!str || *str != '=') + slub_debug = DEBUG_DEFAULT_FLAGS; + else { + str++; + if (*str == 0 || *str == ',') + slub_debug = DEBUG_DEFAULT_FLAGS; + else + for( ;*str && *str != ','; str++) + switch (*str) { + case 'f' : case 'F' : + slub_debug |= SLAB_DEBUG_FREE; + break; + case 'z' : case 'Z' : + slub_debug |= SLAB_RED_ZONE; + break; + case 'p' : case 'P' : + slub_debug |= SLAB_POISON; + break; + case 'u' : case 'U' : + slub_debug |= SLAB_STORE_USER; + break; + case 't' : case 'T' : + slub_debug |= SLAB_TRACE; + break; + default: + printk(KERN_ERR "slub_debug option '%c' " + "unknown. skipped\n",*str); + } + } + + if (*str == ',') + slub_debug_slabs = str + 1; + return 1; +} + +__setup("slub_debug", setup_slub_debug); + +static void kmem_cache_open_debug_check(struct kmem_cache *s) +{ + /* + * The page->offset field is only 16 bit wide. This is an offset + * in units of words from the beginning of an object. If the slab + * size is bigger then we cannot move the free pointer behind the + * object anymore. + * + * On 32 bit platforms the limit is 256k. On 64bit platforms + * the limit is 512k. + * + * Debugging or ctor/dtors may create a need to move the free + * pointer. Fail if this happens. + */ + if (s->size >= 65535 * sizeof(void *)) { + BUG_ON(s->flags & (SLAB_RED_ZONE | SLAB_POISON | + SLAB_STORE_USER | SLAB_DESTROY_BY_RCU)); + BUG_ON(s->ctor || s->dtor); + } + else + /* + * Enable debugging if selected on the kernel commandline. + */ + if (slub_debug && (!slub_debug_slabs || + strncmp(slub_debug_slabs, s->name, + strlen(slub_debug_slabs)) == 0)) + s->flags |= slub_debug; +} +#else + +static inline int alloc_object_checks(struct kmem_cache *s, + struct page *page, void *object) { return 0; } + +static inline int free_object_checks(struct kmem_cache *s, + struct page *page, void *object) { return 0; } + +static inline void add_full(struct kmem_cache_node *n, struct page *page) {} +static inline void remove_full(struct kmem_cache *s, struct page *page) {} +static inline void trace(struct kmem_cache *s, struct page *page, + void *object, int alloc) {} +static inline void init_object(struct kmem_cache *s, + void *object, int active) {} +static inline void init_tracking(struct kmem_cache *s, void *object) {} +static inline int slab_pad_check(struct kmem_cache *s, struct page *page) + { return 1; } +static inline int check_object(struct kmem_cache *s, struct page *page, + void *object, int active) { return 1; } +static inline void set_track(struct kmem_cache *s, void *object, + enum track_item alloc, void *addr) {} +static inline void kmem_cache_open_debug_check(struct kmem_cache *s) {} +#define slub_debug 0 +#endif /* * Slab allocation and freeing */ @@ -1445,13 +1552,6 @@ static int slub_min_objects = DEFAULT_MIN_OBJECTS; */ static int slub_nomerge; -/* - * Debug settings: - */ -static int slub_debug; - -static char *slub_debug_slabs; - /* * Calculate the order of allocation given an slab object size. * @@ -1660,6 +1760,7 @@ static int calculate_sizes(struct kmem_cache *s) */ size = ALIGN(size, sizeof(void *)); +#ifdef CONFIG_SLUB_DEBUG /* * If we are Redzoning then check if there is some space between the * end of the object and the free pointer. If not then add an @@ -1667,6 +1768,7 @@ static int calculate_sizes(struct kmem_cache *s) */ if ((flags & SLAB_RED_ZONE) && size == s->objsize) size += sizeof(void *); +#endif /* * With that we have determined the number of bytes in actual use @@ -1674,6 +1776,7 @@ static int calculate_sizes(struct kmem_cache *s) */ s->inuse = size; +#ifdef CONFIG_SLUB_DEBUG if (((flags & (SLAB_DESTROY_BY_RCU | SLAB_POISON)) || s->ctor || s->dtor)) { /* @@ -1704,6 +1807,7 @@ static int calculate_sizes(struct kmem_cache *s) * of the object. */ size += sizeof(void *); +#endif /* * Determine the alignment based on various parameters that the @@ -1753,32 +1857,7 @@ static int kmem_cache_open(struct kmem_cache *s, gfp_t gfpflags, s->objsize = size; s->flags = flags; s->align = align; - - /* - * The page->offset field is only 16 bit wide. This is an offset - * in units of words from the beginning of an object. If the slab - * size is bigger then we cannot move the free pointer behind the - * object anymore. - * - * On 32 bit platforms the limit is 256k. On 64bit platforms - * the limit is 512k. - * - * Debugging or ctor/dtors may create a need to move the free - * pointer. Fail if this happens. - */ - if (s->size >= 65535 * sizeof(void *)) { - BUG_ON(flags & (SLAB_RED_ZONE | SLAB_POISON | - SLAB_STORE_USER | SLAB_DESTROY_BY_RCU)); - BUG_ON(ctor || dtor); - } - else - /* - * Enable debugging if selected on the kernel commandline. - */ - if (slub_debug && (!slub_debug_slabs || - strncmp(slub_debug_slabs, name, - strlen(slub_debug_slabs)) == 0)) - s->flags |= slub_debug; + kmem_cache_open_debug_check(s); if (!calculate_sizes(s)) goto error; @@ -1949,45 +2028,6 @@ static int __init setup_slub_nomerge(char *str) __setup("slub_nomerge", setup_slub_nomerge); -static int __init setup_slub_debug(char *str) -{ - if (!str || *str != '=') - slub_debug = DEBUG_DEFAULT_FLAGS; - else { - str++; - if (*str == 0 || *str == ',') - slub_debug = DEBUG_DEFAULT_FLAGS; - else - for( ;*str && *str != ','; str++) - switch (*str) { - case 'f' : case 'F' : - slub_debug |= SLAB_DEBUG_FREE; - break; - case 'z' : case 'Z' : - slub_debug |= SLAB_RED_ZONE; - break; - case 'p' : case 'P' : - slub_debug |= SLAB_POISON; - break; - case 'u' : case 'U' : - slub_debug |= SLAB_STORE_USER; - break; - case 't' : case 'T' : - slub_debug |= SLAB_TRACE; - break; - default: - printk(KERN_ERR "slub_debug option '%c' " - "unknown. skipped\n",*str); - } - } - - if (*str == ',') - slub_debug_slabs = str + 1; - return 1; -} - -__setup("slub_debug", setup_slub_debug); - static struct kmem_cache *create_kmalloc_cache(struct kmem_cache *s, const char *name, int size, gfp_t gfp_flags) { @@ -2554,8 +2594,7 @@ void *__kmalloc_node_track_caller(size_t size, gfp_t gfpflags, return slab_alloc(s, gfpflags, node, caller); } -#ifdef CONFIG_SYSFS - +#if defined(CONFIG_SYSFS) && defined(CONFIG_SLUB_DEBUG) static int validate_slab(struct kmem_cache *s, struct page *page) { void *p;