From 3ec0974210fe1b7c0618ad6e39a882a4237d7de2 Mon Sep 17 00:00:00 2001 From: Christoph Lameter Date: Wed, 16 May 2007 22:11:00 -0700 Subject: [PATCH] SLUB: Simplify debug code Consolidate functionality into the #ifdef section. Extract tracing into one subroutine. Move object debug processing into the #ifdef section so that the code in __slab_alloc and __slab_free becomes minimal. Reduce number of functions we need to provide stubs for in the !SLUB_DEBUG case. Signed-off-by: Christoph Lameter Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- mm/slub.c | 112 +++++++++++++++++++++++++++--------------------------- 1 file changed, 57 insertions(+), 55 deletions(-) diff --git a/mm/slub.c b/mm/slub.c index e7ad123bb6a7..98801d404d69 100644 --- a/mm/slub.c +++ b/mm/slub.c @@ -742,6 +742,22 @@ static int on_freelist(struct kmem_cache *s, struct page *page, void *search) return search == NULL; } +static void trace(struct kmem_cache *s, struct page *page, void *object, int alloc) +{ + if (s->flags & SLAB_TRACE) { + printk(KERN_INFO "TRACE %s %s 0x%p inuse=%d fp=0x%p\n", + s->name, + alloc ? "alloc" : "free", + object, page->inuse, + page->freelist); + + if (!alloc) + print_section("Object", (void *)object, s->objsize); + + dump_stack(); + } +} + /* * Tracking of fully allocated slabs for debugging purposes. */ @@ -766,8 +782,18 @@ static void remove_full(struct kmem_cache *s, struct page *page) spin_unlock(&n->list_lock); } -static int alloc_object_checks(struct kmem_cache *s, struct page *page, - void *object) +static void setup_object_debug(struct kmem_cache *s, struct page *page, + void *object) +{ + if (!(s->flags & (SLAB_STORE_USER|SLAB_RED_ZONE|__OBJECT_POISON))) + return; + + init_object(s, object, 0); + init_tracking(s, object); +} + +static int alloc_debug_processing(struct kmem_cache *s, struct page *page, + void *object, void *addr) { if (!check_slab(s, page)) goto bad; @@ -782,13 +808,16 @@ static int alloc_object_checks(struct kmem_cache *s, struct page *page, goto bad; } - if (!object) - return 1; - - if (!check_object(s, page, object, 0)) + if (object && !check_object(s, page, object, 0)) goto bad; + /* Success perform special debug activities for allocs */ + if (s->flags & SLAB_STORE_USER) + set_track(s, object, TRACK_ALLOC, addr); + trace(s, page, object, 1); + init_object(s, object, 1); return 1; + bad: if (PageSlab(page)) { /* @@ -806,8 +835,8 @@ bad: return 0; } -static int free_object_checks(struct kmem_cache *s, struct page *page, - void *object) +static int free_debug_processing(struct kmem_cache *s, struct page *page, + void *object, void *addr) { if (!check_slab(s, page)) goto fail; @@ -841,29 +870,22 @@ static int free_object_checks(struct kmem_cache *s, struct page *page, "to slab %s", object, page->slab->name); goto fail; } + + /* Special debug activities for freeing objects */ + if (!SlabFrozen(page) && !page->freelist) + remove_full(s, page); + if (s->flags & SLAB_STORE_USER) + set_track(s, object, TRACK_FREE, addr); + trace(s, page, object, 0); + init_object(s, object, 0); return 1; + fail: printk(KERN_ERR "@@@ SLUB: %s slab 0x%p object at 0x%p not freed.\n", s->name, page, object); return 0; } -static void trace(struct kmem_cache *s, struct page *page, void *object, int alloc) -{ - if (s->flags & SLAB_TRACE) { - printk(KERN_INFO "TRACE %s %s 0x%p inuse=%d fp=0x%p\n", - s->name, - alloc ? "alloc" : "free", - object, page->inuse, - page->freelist); - - if (!alloc) - print_section("Object", (void *)object, s->objsize); - - dump_stack(); - } -} - static int __init setup_slub_debug(char *str) { if (!str || *str != '=') @@ -932,26 +954,20 @@ static void kmem_cache_open_debug_check(struct kmem_cache *s) s->flags |= slub_debug; } #else +static inline void setup_object_debug(struct kmem_cache *s, + struct page *page, void *object) {} -static inline int alloc_object_checks(struct kmem_cache *s, - struct page *page, void *object) { return 0; } +static inline int alloc_debug_processing(struct kmem_cache *s, + struct page *page, void *object, void *addr) { return 0; } -static inline int free_object_checks(struct kmem_cache *s, - struct page *page, void *object) { return 0; } +static inline int free_debug_processing(struct kmem_cache *s, + struct page *page, void *object, void *addr) { 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 add_full(struct kmem_cache_node *n, struct page *page) {} static inline void kmem_cache_open_debug_check(struct kmem_cache *s) {} #define slub_debug 0 #endif @@ -988,11 +1004,7 @@ static struct page *allocate_slab(struct kmem_cache *s, gfp_t flags, int node) static void setup_object(struct kmem_cache *s, struct page *page, void *object) { - if (SlabDebug(page)) { - init_object(s, object, 0); - init_tracking(s, object); - } - + setup_object_debug(s, page, object); if (unlikely(s->ctor)) s->ctor(object, s, 0); } @@ -1449,12 +1461,8 @@ new_slab: return NULL; debug: object = page->freelist; - if (!alloc_object_checks(s, page, object)) + if (!alloc_debug_processing(s, page, object, addr)) goto another_slab; - if (s->flags & SLAB_STORE_USER) - set_track(s, object, TRACK_ALLOC, addr); - trace(s, page, object, 1); - init_object(s, object, 1); page->inuse++; page->freelist = object[page->offset]; @@ -1561,14 +1569,8 @@ slab_empty: return; debug: - if (!free_object_checks(s, page, x)) + if (!free_debug_processing(s, page, x, addr)) goto out_unlock; - if (!SlabFrozen(page) && !page->freelist) - remove_full(s, page); - if (s->flags & SLAB_STORE_USER) - set_track(s, x, TRACK_FREE, addr); - trace(s, page, object, 0); - init_object(s, object, 0); goto checks_ok; } @@ -1805,7 +1807,7 @@ static struct kmem_cache_node * __init early_kmem_cache_node_alloc(gfp_t gfpflag page->freelist = get_freepointer(kmalloc_caches, n); page->inuse++; kmalloc_caches->node[node] = n; - init_object(kmalloc_caches, n, 1); + setup_object_debug(kmalloc_caches, page, n); init_kmem_cache_node(n); atomic_long_inc(&n->nr_slabs); add_partial(n, page); -- 2.20.1