Commit 4ef3f5a3 authored by Vlastimil Babka's avatar Vlastimil Babka
Browse files

mm/slub: convert object_map_lock to non-raw spinlock 



The only remaining user of object_map_lock is list_slab_objects().
Obtaining the lock there used to happen under slab_lock() which implied
disabling irqs on PREEMPT_RT, thus it's a raw_spinlock. With the
slab_lock() removed, we can convert it to a normal spinlock.

Also remove the get_map()/put_map() wrappers as list_slab_objects()
became their only remaining user.

Signed-off-by: default avatarVlastimil Babka <vbabka@suse.cz>
Acked-by: default avatarDavid Rientjes <rientjes@google.com>
Reviewed-by: default avatarHyeonggon Yoo <42.hyeyoo@gmail.com>
Reviewed-by: default avatarSebastian Andrzej Siewior <bigeasy@linutronix.de>
parent 41bec7c3

mm/slub.c

+6 −30
Original line number Diff line number Diff line
@@ -565,7 +565,7 @@ static inline bool cmpxchg_double_slab(struct kmem_cache *s, struct slab *slab, 


#ifdef CONFIG_SLUB_DEBUG

static unsigned long object_map[BITS_TO_LONGS(MAX_OBJS_PER_PAGE)];

static DEFINE_RAW_SPINLOCK(object_map_lock);

static DEFINE_SPINLOCK(object_map_lock);



static void __fill_map(unsigned long *obj_map, struct kmem_cache *s,

		       struct slab *slab)
@@ -599,30 +599,6 @@ static bool slab_add_kunit_errors(void) 
static inline bool slab_add_kunit_errors(void) { return false; }

#endif



/*

 * Determine a map of objects in use in a slab.

 *

 * Node listlock must be held to guarantee that the slab does

 * not vanish from under us.

 */

static unsigned long *get_map(struct kmem_cache *s, struct slab *slab)

	__acquires(&object_map_lock)

{

	VM_BUG_ON(!irqs_disabled());



	raw_spin_lock(&object_map_lock);



	__fill_map(object_map, s, slab);



	return object_map;

}



static void put_map(unsigned long *map) __releases(&object_map_lock)

{

	VM_BUG_ON(map != object_map);

	raw_spin_unlock(&object_map_lock);

}



static inline unsigned int size_from_object(struct kmem_cache *s)

{

	if (s->flags & SLAB_RED_ZONE)
@@ -4368,21 +4344,21 @@ static void list_slab_objects(struct kmem_cache *s, struct slab *slab, 
{

#ifdef CONFIG_SLUB_DEBUG

	void *addr = slab_address(slab);

	unsigned long flags;

	unsigned long *map;

	void *p;



	slab_err(s, slab, text, s->name);



	map = get_map(s, slab);

	spin_lock(&object_map_lock);

	__fill_map(object_map, s, slab);



	for_each_object(p, s, addr, slab->objects) {



		if (!test_bit(__obj_to_index(s, addr, p), map)) {

		if (!test_bit(__obj_to_index(s, addr, p), object_map)) {

			pr_err("Object 0x%p @offset=%tu\n", p, p - addr);

			print_tracking(s, p);

		}

	}

	put_map(map);

	spin_unlock(&object_map_lock);

#endif

}