From 02e72cc61713185013d958baba508288ba2a0157 Mon Sep 17 00:00:00 2001 From: Andrey Ryabinin Date: Wed, 6 Aug 2014 16:04:18 -0700 Subject: [PATCH] mm: slub: SLUB_DEBUG=n: use the same alloc/free hooks as for SLUB_DEBUG=y There are two versions of alloc/free hooks now - one for CONFIG_SLUB_DEBUG=y and another one for CONFIG_SLUB_DEBUG=n. I see no reason why calls to other debugging subsystems (LOCKDEP, DEBUG_ATOMIC_SLEEP, KMEMCHECK and FAILSLAB) are hidden under SLUB_DEBUG. All this features should work regardless of SLUB_DEBUG config, as all of them already have own Kconfig options. This also fixes failslab for CONFIG_SLUB_DEBUG=n configuration. It simply has not worked before because should_failslab() call was in a hook hidden under "#ifdef CONFIG_SLUB_DEBUG #else". Note: There is one concealed change in allocation path for SLUB_DEBUG=n and all other debugging features disabled. The might_sleep_if() call can generate some code even if DEBUG_ATOMIC_SLEEP=n. For PREEMPT_VOLUNTARY=y might_sleep() inserts _cond_resched() call, but I think it should be ok. Signed-off-by: Andrey Ryabinin Cc: Christoph Lameter Cc: Pekka Enberg Cc: David Rientjes Cc: Joonsoo Kim Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- mm/slub.c | 99 +++++++++++++++++++++---------------------------------- 1 file changed, 37 insertions(+), 62 deletions(-) diff --git a/mm/slub.c b/mm/slub.c index 2d61503efb92..92d8139c556d 100644 --- a/mm/slub.c +++ b/mm/slub.c @@ -939,60 +939,6 @@ static void trace(struct kmem_cache *s, struct page *page, void *object, } } -/* - * Hooks for other subsystems that check memory allocations. In a typical - * production configuration these hooks all should produce no code at all. - */ -static inline void kmalloc_large_node_hook(void *ptr, size_t size, gfp_t flags) -{ - kmemleak_alloc(ptr, size, 1, flags); -} - -static inline void kfree_hook(const void *x) -{ - kmemleak_free(x); -} - -static inline int slab_pre_alloc_hook(struct kmem_cache *s, gfp_t flags) -{ - flags &= gfp_allowed_mask; - lockdep_trace_alloc(flags); - might_sleep_if(flags & __GFP_WAIT); - - return should_failslab(s->object_size, flags, s->flags); -} - -static inline void slab_post_alloc_hook(struct kmem_cache *s, - gfp_t flags, void *object) -{ - flags &= gfp_allowed_mask; - kmemcheck_slab_alloc(s, flags, object, slab_ksize(s)); - kmemleak_alloc_recursive(object, s->object_size, 1, s->flags, flags); -} - -static inline void slab_free_hook(struct kmem_cache *s, void *x) -{ - kmemleak_free_recursive(x, s->flags); - - /* - * Trouble is that we may no longer disable interrupts in the fast path - * So in order to make the debug calls that expect irqs to be - * disabled we need to disable interrupts temporarily. - */ -#if defined(CONFIG_KMEMCHECK) || defined(CONFIG_LOCKDEP) - { - unsigned long flags; - - local_irq_save(flags); - kmemcheck_slab_free(s, x, s->object_size); - debug_check_no_locks_freed(x, s->object_size); - local_irq_restore(flags); - } -#endif - if (!(s->flags & SLAB_DEBUG_OBJECTS)) - debug_check_no_obj_freed(x, s->object_size); -} - /* * Tracking of fully allocated slabs for debugging purposes. */ @@ -1277,6 +1223,12 @@ static inline void inc_slabs_node(struct kmem_cache *s, int node, static inline void dec_slabs_node(struct kmem_cache *s, int node, int objects) {} +#endif /* CONFIG_SLUB_DEBUG */ + +/* + * Hooks for other subsystems that check memory allocations. In a typical + * production configuration these hooks all should produce no code at all. + */ static inline void kmalloc_large_node_hook(void *ptr, size_t size, gfp_t flags) { kmemleak_alloc(ptr, size, 1, flags); @@ -1288,21 +1240,44 @@ static inline void kfree_hook(const void *x) } static inline int slab_pre_alloc_hook(struct kmem_cache *s, gfp_t flags) - { return 0; } - -static inline void slab_post_alloc_hook(struct kmem_cache *s, gfp_t flags, - void *object) { - kmemleak_alloc_recursive(object, s->object_size, 1, s->flags, - flags & gfp_allowed_mask); + flags &= gfp_allowed_mask; + lockdep_trace_alloc(flags); + might_sleep_if(flags & __GFP_WAIT); + + return should_failslab(s->object_size, flags, s->flags); +} + +static inline void slab_post_alloc_hook(struct kmem_cache *s, + gfp_t flags, void *object) +{ + flags &= gfp_allowed_mask; + kmemcheck_slab_alloc(s, flags, object, slab_ksize(s)); + kmemleak_alloc_recursive(object, s->object_size, 1, s->flags, flags); } static inline void slab_free_hook(struct kmem_cache *s, void *x) { kmemleak_free_recursive(x, s->flags); -} -#endif /* CONFIG_SLUB_DEBUG */ + /* + * Trouble is that we may no longer disable interrupts in the fast path + * So in order to make the debug calls that expect irqs to be + * disabled we need to disable interrupts temporarily. + */ +#if defined(CONFIG_KMEMCHECK) || defined(CONFIG_LOCKDEP) + { + unsigned long flags; + + local_irq_save(flags); + kmemcheck_slab_free(s, x, s->object_size); + debug_check_no_locks_freed(x, s->object_size); + local_irq_restore(flags); + } +#endif + if (!(s->flags & SLAB_DEBUG_OBJECTS)) + debug_check_no_obj_freed(x, s->object_size); +} /* * Slab allocation and freeing