#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;
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;
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)
{
static void fill_pool(void)
{
gfp_t gfp = GFP_ATOMIC | __GFP_NORETRY | __GFP_NOWARN;
- struct debug_obj *new, *obj;
+ struct debug_obj *obj;
unsigned long flags;
if (likely(obj_pool_free >= debug_objects_pool_min_level))
* Recheck with the lock held as the worker thread might have
* won the race and freed the global free list already.
*/
- if (obj_nr_tofree) {
+ while (obj_nr_tofree && (obj_pool_free < obj_pool_min_free)) {
obj = hlist_entry(obj_to_free.first, typeof(*obj), node);
hlist_del(&obj->node);
obj_nr_tofree--;
return;
while (obj_pool_free < debug_objects_pool_min_level) {
+ struct debug_obj *new[ODEBUG_BATCH_SIZE];
+ int cnt;
- new = kmem_cache_zalloc(obj_cache, gfp);
- if (!new)
+ for (cnt = 0; cnt < ODEBUG_BATCH_SIZE; cnt++) {
+ new[cnt] = kmem_cache_zalloc(obj_cache, gfp);
+ if (!new[cnt])
+ break;
+ }
+ if (!cnt)
return;
raw_spin_lock_irqsave(&pool_lock, flags);
- hlist_add_head(&new->node, &obj_pool);
- debug_objects_allocated++;
- obj_pool_free++;
+ while (cnt) {
+ hlist_add_head(&new[--cnt]->node, &obj_pool);
+ debug_objects_allocated++;
+ obj_pool_free++;
+ }
raw_spin_unlock_irqrestore(&pool_lock, flags);
}
}
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);
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
}
}
-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;
hlist_add_head(&obj->node, &percpu_pool->free_objs);
percpu_pool->obj_free++;
local_irq_restore(flags);
- return false;
+ return;
}
/*
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) {
&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);
}
raw_spin_unlock(&pool_lock);
local_irq_restore(flags);
- return work;
}
/*
*/
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);
+ }
}
/*
__debug_object_init(void *addr, struct debug_obj_descr *descr, int onstack)
{
enum debug_obj_state state;
+ bool check_stack = false;
struct debug_bucket *db;
struct debug_obj *obj;
unsigned long flags;
debug_objects_oom();
return;
}
- debug_object_is_on_stack(addr, onstack);
+ check_stack = true;
}
switch (obj->state) {
break;
case ODEBUG_STATE_ACTIVE:
- debug_print_object(obj, "init");
state = obj->state;
raw_spin_unlock_irqrestore(&db->lock, flags);
+ debug_print_object(obj, "init");
debug_object_fixup(descr->fixup_init, addr, state);
return;
case ODEBUG_STATE_DESTROYED:
+ raw_spin_unlock_irqrestore(&db->lock, flags);
debug_print_object(obj, "init");
- break;
+ return;
default:
break;
}
raw_spin_unlock_irqrestore(&db->lock, flags);
+ if (check_stack)
+ debug_object_is_on_stack(addr, onstack);
}
/**
obj = lookup_object(addr, db);
if (obj) {
+ bool print_object = false;
+
switch (obj->state) {
case ODEBUG_STATE_INIT:
case ODEBUG_STATE_INACTIVE:
break;
case ODEBUG_STATE_ACTIVE:
- debug_print_object(obj, "activate");
state = obj->state;
raw_spin_unlock_irqrestore(&db->lock, flags);
+ debug_print_object(obj, "activate");
ret = debug_object_fixup(descr->fixup_activate, addr, state);
return ret ? 0 : -EINVAL;
case ODEBUG_STATE_DESTROYED:
- debug_print_object(obj, "activate");
+ print_object = true;
ret = -EINVAL;
break;
default:
break;
}
raw_spin_unlock_irqrestore(&db->lock, flags);
+ if (print_object)
+ debug_print_object(obj, "activate");
return ret;
}
raw_spin_unlock_irqrestore(&db->lock, flags);
+
/*
* We are here when a static object is activated. We
* let the type specific code confirm whether this is
struct debug_bucket *db;
struct debug_obj *obj;
unsigned long flags;
+ bool print_object = false;
if (!debug_objects_enabled)
return;
if (!obj->astate)
obj->state = ODEBUG_STATE_INACTIVE;
else
- debug_print_object(obj, "deactivate");
+ print_object = true;
break;
case ODEBUG_STATE_DESTROYED:
- debug_print_object(obj, "deactivate");
+ print_object = true;
break;
default:
break;
}
- } else {
+ }
+
+ raw_spin_unlock_irqrestore(&db->lock, flags);
+ if (!obj) {
struct debug_obj o = { .object = addr,
.state = ODEBUG_STATE_NOTAVAILABLE,
.descr = descr };
debug_print_object(&o, "deactivate");
+ } else if (print_object) {
+ debug_print_object(obj, "deactivate");
}
-
- raw_spin_unlock_irqrestore(&db->lock, flags);
}
EXPORT_SYMBOL_GPL(debug_object_deactivate);
struct debug_bucket *db;
struct debug_obj *obj;
unsigned long flags;
+ bool print_object = false;
if (!debug_objects_enabled)
return;
obj->state = ODEBUG_STATE_DESTROYED;
break;
case ODEBUG_STATE_ACTIVE:
- debug_print_object(obj, "destroy");
state = obj->state;
raw_spin_unlock_irqrestore(&db->lock, flags);
+ debug_print_object(obj, "destroy");
debug_object_fixup(descr->fixup_destroy, addr, state);
return;
case ODEBUG_STATE_DESTROYED:
- debug_print_object(obj, "destroy");
+ print_object = true;
break;
default:
break;
}
out_unlock:
raw_spin_unlock_irqrestore(&db->lock, flags);
+ if (print_object)
+ debug_print_object(obj, "destroy");
}
EXPORT_SYMBOL_GPL(debug_object_destroy);
switch (obj->state) {
case ODEBUG_STATE_ACTIVE:
- debug_print_object(obj, "free");
state = obj->state;
raw_spin_unlock_irqrestore(&db->lock, flags);
+ debug_print_object(obj, "free");
debug_object_fixup(descr->fixup_free, addr, state);
return;
default:
struct debug_bucket *db;
struct debug_obj *obj;
unsigned long flags;
+ bool print_object = false;
if (!debug_objects_enabled)
return;
if (obj->astate == expect)
obj->astate = next;
else
- debug_print_object(obj, "active_state");
+ print_object = true;
break;
default:
- debug_print_object(obj, "active_state");
+ print_object = true;
break;
}
- } else {
+ }
+
+ raw_spin_unlock_irqrestore(&db->lock, flags);
+ if (!obj) {
struct debug_obj o = { .object = addr,
.state = ODEBUG_STATE_NOTAVAILABLE,
.descr = descr };
debug_print_object(&o, "active_state");
+ } else if (print_object) {
+ debug_print_object(obj, "active_state");
}
-
- raw_spin_unlock_irqrestore(&db->lock, flags);
}
EXPORT_SYMBOL_GPL(debug_object_active_state);
struct hlist_node *tmp;
struct debug_obj *obj;
int cnt, objs_checked = 0;
- bool work = false;
saddr = (unsigned long) address;
eaddr = saddr + size;
switch (obj->state) {
case ODEBUG_STATE_ACTIVE:
- debug_print_object(obj, "free");
descr = obj->descr;
state = obj->state;
raw_spin_unlock_irqrestore(&db->lock, flags);
+ debug_print_object(obj, "free");
debug_object_fixup(descr->fixup_free,
(void *) oaddr, state);
goto repeat;
default:
hlist_del(&obj->node);
- work |= __free_object(obj);
+ __free_object(obj);
break;
}
}
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)