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Commit 575260e3 authored by Linus Torvalds's avatar Linus Torvalds
Browse files

Merge branch 'core-debugobjects-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 

Pull debugobjects updates from Ingo Molnar:
 "A number of scalability improvements by Waimang Long"

* 'core-debugobjects-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  debugobjects: Improve variable naming
  debugobjects: Reduce contention on the global pool_lock
  debugobjects: Scale thresholds with # of CPUs
  debugobjects: Track number of kmem_cache_alloc/kmem_cache_free done
parents 1cd4027c 0cad93c3

lib/debugobjects.c

+46 −12
Original line number Diff line number Diff line
@@ -52,9 +52,18 @@ static int debug_objects_fixups __read_mostly; 
static int			debug_objects_warnings __read_mostly;

static int			debug_objects_enabled __read_mostly

				= CONFIG_DEBUG_OBJECTS_ENABLE_DEFAULT;



static int			debug_objects_pool_size __read_mostly

				= ODEBUG_POOL_SIZE;

static int			debug_objects_pool_min_level __read_mostly

				= ODEBUG_POOL_MIN_LEVEL;

static struct debug_obj_descr	*descr_test  __read_mostly;



/*

 * Track numbers of kmem_cache_alloc()/free() calls done.

 */

static int			debug_objects_allocated;

static int			debug_objects_freed;



static void free_obj_work(struct work_struct *work);

static DECLARE_WORK(debug_obj_work, free_obj_work);
@@ -88,13 +97,13 @@ static void fill_pool(void) 
	struct debug_obj *new;

	unsigned long flags;



	if (likely(obj_pool_free >= ODEBUG_POOL_MIN_LEVEL))

	if (likely(obj_pool_free >= debug_objects_pool_min_level))

		return;



	if (unlikely(!obj_cache))

		return;



	while (obj_pool_free < ODEBUG_POOL_MIN_LEVEL) {

	while (obj_pool_free < debug_objects_pool_min_level) {



		new = kmem_cache_zalloc(obj_cache, gfp);

		if (!new)
@@ -102,6 +111,7 @@ static void fill_pool(void) 


		raw_spin_lock_irqsave(&pool_lock, flags);

		hlist_add_head(&new->node, &obj_pool);

		debug_objects_allocated++;

		obj_pool_free++;

		raw_spin_unlock_irqrestore(&pool_lock, flags);

	}
@@ -162,24 +172,39 @@ alloc_object(void *addr, struct debug_bucket *b, struct debug_obj_descr *descr) 


/*

 * workqueue function to free objects.

 *

 * To reduce contention on the global pool_lock, the actual freeing of

 * debug objects will be delayed if the pool_lock is busy. We also free

 * the objects in a batch of 4 for each lock/unlock cycle.

 */

#define ODEBUG_FREE_BATCH	4



static void free_obj_work(struct work_struct *work)

{

	struct debug_obj *obj;

	struct debug_obj *objs[ODEBUG_FREE_BATCH];

	unsigned long flags;

	int i;



	raw_spin_lock_irqsave(&pool_lock, flags);

	while (obj_pool_free > ODEBUG_POOL_SIZE) {

		obj = hlist_entry(obj_pool.first, typeof(*obj), node);

		hlist_del(&obj->node);

		obj_pool_free--;

	if (!raw_spin_trylock_irqsave(&pool_lock, flags))

		return;

	while (obj_pool_free >= debug_objects_pool_size + ODEBUG_FREE_BATCH) {

		for (i = 0; i < ODEBUG_FREE_BATCH; i++) {

			objs[i] = hlist_entry(obj_pool.first,

					      typeof(*objs[0]), node);

			hlist_del(&objs[i]->node);

		}



		obj_pool_free -= ODEBUG_FREE_BATCH;

		debug_objects_freed += ODEBUG_FREE_BATCH;

		/*

		 * We release pool_lock across kmem_cache_free() to

		 * avoid contention on pool_lock.

		 */

		raw_spin_unlock_irqrestore(&pool_lock, flags);

		kmem_cache_free(obj_cache, obj);

		raw_spin_lock_irqsave(&pool_lock, flags);

		for (i = 0; i < ODEBUG_FREE_BATCH; i++)

			kmem_cache_free(obj_cache, objs[i]);

		if (!raw_spin_trylock_irqsave(&pool_lock, flags))

			return;

	}

	raw_spin_unlock_irqrestore(&pool_lock, flags);

}
@@ -198,7 +223,7 @@ static void free_object(struct debug_obj *obj) 
	 * schedule work when the pool is filled and the cache is

	 * initialized:

	 */

	if (obj_pool_free > ODEBUG_POOL_SIZE && obj_cache)

	if (obj_pool_free > debug_objects_pool_size && obj_cache)

		sched = 1;

	hlist_add_head(&obj->node, &obj_pool);

	obj_pool_free++;
@@ -758,6 +783,8 @@ static int debug_stats_show(struct seq_file *m, void *v) 
	seq_printf(m, "pool_min_free :%d\n", obj_pool_min_free);

	seq_printf(m, "pool_used     :%d\n", obj_pool_used);

	seq_printf(m, "pool_max_used :%d\n", obj_pool_max_used);

	seq_printf(m, "objs_allocated:%d\n", debug_objects_allocated);

	seq_printf(m, "objs_freed    :%d\n", debug_objects_freed);

	return 0;

}
@@ -1116,4 +1143,11 @@ void __init debug_objects_mem_init(void) 
		pr_warn("out of memory.\n");

	} else

		debug_objects_selftest();



	/*

	 * Increase the thresholds for allocating and freeing objects

	 * according to the number of possible CPUs available in the system.

	 */

	debug_objects_pool_size += num_possible_cpus() * 32;

	debug_objects_pool_min_level += num_possible_cpus() * 4;

}