sbitmap_prepare_to_wait
sbitmap_prepare_to_wait(bt, ws, &wait, TASK_UNINTERRUPTIBLE);
sbitmap_prepare_to_wait(sbq, ws, &wait, TASK_INTERRUPTIBLE);
sbitmap_prepare_to_wait(sbq, ws, &wait, TASK_UNINTERRUPTIBLE);
sbitmap_prepare_to_wait(sbq, ws, &wait, state);
void sbitmap_prepare_to_wait(struct sbitmap_queue *sbq,
EXPORT_SYMBOL_GPL(sbitmap_prepare_to_wait);