diff options
| -rw-r--r-- | lib/debugobjects.c | 61 |
1 files changed, 49 insertions, 12 deletions
diff --git a/lib/debugobjects.c b/lib/debugobjects.c index 7ea19fa63561..ede96c659552 100644 --- a/lib/debugobjects.c +++ b/lib/debugobjects.c @@ -32,6 +32,14 @@ #define ODEBUG_CHUNK_SIZE (1 << ODEBUG_CHUNK_SHIFT) #define ODEBUG_CHUNK_MASK (~(ODEBUG_CHUNK_SIZE - 1)) +/* + * We limit the freeing of debug objects via workqueue at a maximum + * frequency of 10Hz and about 1024 objects for each freeing operation. + * So it is freeing at most 10k debug objects per second. + */ +#define ODEBUG_FREE_WORK_MAX 1024 +#define ODEBUG_FREE_WORK_DELAY DIV_ROUND_UP(HZ, 10) + struct debug_bucket { struct hlist_head list; raw_spinlock_t lock; @@ -68,6 +76,7 @@ static int obj_pool_min_free = ODEBUG_POOL_SIZE; static int obj_pool_free = ODEBUG_POOL_SIZE; static int obj_pool_used; static int obj_pool_max_used; +static bool obj_freeing; /* The number of objs on the global free list */ static int obj_nr_tofree; @@ -91,7 +100,7 @@ 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); +static DECLARE_DELAYED_WORK(debug_obj_work, free_obj_work); static int __init enable_object_debug(char *str) { @@ -282,13 +291,19 @@ static void free_obj_work(struct work_struct *work) unsigned long flags; HLIST_HEAD(tofree); + WRITE_ONCE(obj_freeing, false); if (!raw_spin_trylock_irqsave(&pool_lock, flags)) return; + if (obj_pool_free >= debug_objects_pool_size) + goto free_objs; + /* * The objs on the pool list might be allocated before the work is * run, so recheck if pool list it full or not, if not fill pool - * list from the global free list. + * list from the global free list. As it is likely that a workload + * may be gearing up to use more and more objects, don't free any + * of them until the next round. */ while (obj_nr_tofree && obj_pool_free < debug_objects_pool_size) { obj = hlist_entry(obj_to_free.first, typeof(*obj), node); @@ -297,7 +312,10 @@ static void free_obj_work(struct work_struct *work) obj_pool_free++; obj_nr_tofree--; } + raw_spin_unlock_irqrestore(&pool_lock, flags); + return; +free_objs: /* * Pool list is already full and there are still objs on the free * list. Move remaining free objs to a temporary list to free the @@ -316,7 +334,7 @@ static void free_obj_work(struct work_struct *work) } } -static bool __free_object(struct debug_obj *obj) +static void __free_object(struct debug_obj *obj) { struct debug_obj *objs[ODEBUG_BATCH_SIZE]; struct debug_percpu_free *percpu_pool; @@ -336,7 +354,7 @@ static bool __free_object(struct debug_obj *obj) hlist_add_head(&obj->node, &percpu_pool->free_objs); percpu_pool->obj_free++; local_irq_restore(flags); - return false; + return; } /* @@ -352,7 +370,8 @@ static bool __free_object(struct debug_obj *obj) free_to_obj_pool: raw_spin_lock(&pool_lock); - work = (obj_pool_free > debug_objects_pool_size) && obj_cache; + work = (obj_pool_free > debug_objects_pool_size) && obj_cache && + (obj_nr_tofree < ODEBUG_FREE_WORK_MAX); obj_pool_used--; if (work) { @@ -366,6 +385,21 @@ free_to_obj_pool: &obj_to_free); } } + + if ((obj_pool_free > debug_objects_pool_size) && + (obj_nr_tofree < ODEBUG_FREE_WORK_MAX)) { + int i; + + /* + * Free one more batch of objects from obj_pool. + */ + for (i = 0; i < ODEBUG_BATCH_SIZE; i++) { + obj = __alloc_object(&obj_pool); + hlist_add_head(&obj->node, &obj_to_free); + obj_pool_free--; + obj_nr_tofree++; + } + } } else { obj_pool_free++; hlist_add_head(&obj->node, &obj_pool); @@ -380,7 +414,6 @@ free_to_obj_pool: } raw_spin_unlock(&pool_lock); local_irq_restore(flags); - return work; } /* @@ -389,8 +422,11 @@ free_to_obj_pool: */ static void free_object(struct debug_obj *obj) { - if (__free_object(obj)) - schedule_work(&debug_obj_work); + __free_object(obj); + if (!obj_freeing && obj_nr_tofree) { + WRITE_ONCE(obj_freeing, true); + schedule_delayed_work(&debug_obj_work, ODEBUG_FREE_WORK_DELAY); + } } /* @@ -880,7 +916,6 @@ static void __debug_check_no_obj_freed(const void *address, unsigned long size) struct hlist_node *tmp; struct debug_obj *obj; int cnt, objs_checked = 0; - bool work = false; saddr = (unsigned long) address; eaddr = saddr + size; @@ -911,7 +946,7 @@ repeat: goto repeat; default: hlist_del(&obj->node); - work |= __free_object(obj); + __free_object(obj); break; } } @@ -927,8 +962,10 @@ repeat: debug_objects_maxchecked = objs_checked; /* Schedule work to actually kmem_cache_free() objects */ - if (work) - schedule_work(&debug_obj_work); + if (!obj_freeing && obj_nr_tofree) { + WRITE_ONCE(obj_freeing, true); + schedule_delayed_work(&debug_obj_work, ODEBUG_FREE_WORK_DELAY); + } } void debug_check_no_obj_freed(const void *address, unsigned long size) |