struct io_sq_data {
refcount_t refs;
+ atomic_t park_pending;
struct mutex lock;
/* ctx's that are using this sqd */
{
WARN_ON_ONCE(sqd->thread == current);
+ /*
+ * Do the dance but not conditional clear_bit() because it'd race with
+ * other threads incrementing park_pending and setting the bit.
+ */
clear_bit(IO_SQ_THREAD_SHOULD_PARK, &sqd->state);
+ if (atomic_dec_return(&sqd->park_pending))
+ set_bit(IO_SQ_THREAD_SHOULD_PARK, &sqd->state);
mutex_unlock(&sqd->lock);
}
{
WARN_ON_ONCE(sqd->thread == current);
+ atomic_inc(&sqd->park_pending);
set_bit(IO_SQ_THREAD_SHOULD_PARK, &sqd->state);
mutex_lock(&sqd->lock);
- /* set again for consistency, in case concurrent parks are happening */
- set_bit(IO_SQ_THREAD_SHOULD_PARK, &sqd->state);
if (sqd->thread)
wake_up_process(sqd->thread);
}
static void io_put_sq_data(struct io_sq_data *sqd)
{
if (refcount_dec_and_test(&sqd->refs)) {
+ WARN_ON_ONCE(atomic_read(&sqd->park_pending));
+
io_sq_thread_stop(sqd);
kfree(sqd);
}
if (!sqd)
return ERR_PTR(-ENOMEM);
+ atomic_set(&sqd->park_pending, 0);
refcount_set(&sqd->refs, 1);
INIT_LIST_HEAD(&sqd->ctx_list);
mutex_init(&sqd->lock);