On 4/12/21 7:55 PM, Changheun Lee wrote:

+unsigned int bio_max_size(struct bio *bio)
+{
+	struct request_queue *q = bio->bi_bdev->bd_disk->queue;
+
+	if (blk_queue_limit_bio_size(q))
+		return blk_queue_get_max_sectors(q, bio_op(bio))
+			<< SECTOR_SHIFT;
+
+	return UINT_MAX;
+}

This patch adds an if-statement to the hot path and that may have a
slight negative performance impact. I recommend to follow the approach
of max_hw_sectors. That means removing QUEUE_FLAG_LIMIT_BIO_SIZE and to
initialize the maximum bio size to UINT_MAX in blk_set_default_limits().

Thanks,

Bart.