Function test_merge

test/regbuf-clone.c:531–580

* Register sparse buffer table, then try updating that with a few huge * page entries. */

 * page entries.
 */
static int test_merge(void)
{
	int ret, res = T_EXIT_SKIP;
	struct iovec vecs[8];
	struct io_uring ring;
	__u64 tags[2];
	void *p1;

	p1 = mmap(NULL, 2*1024*1024, PROT_READ|PROT_WRITE,
			MAP_PRIVATE|MAP_HUGETLB | MAP_HUGE_2MB | MAP_ANONYMOUS,
			-1, 0);
	if (p1 == MAP_FAILED)
		return T_EXIT_SKIP;

	ret = io_uring_queue_init(1, &ring, 0);
	if (ret) {
		fprintf(stderr, "ring_init: %d\n", ret);
		return T_EXIT_FAIL;
	}

	memset(vecs, 0, sizeof(vecs));

	ret = io_uring_register_buffers(&ring, vecs, 8);
	if (ret < 0) {
		if (ret == -EINVAL)
			goto skip;
		fprintf(stderr, "failed to register initial buffers: %d\n", ret);
		return T_EXIT_FAIL;
	}

	vecs[0].iov_base = p1;
	vecs[0].iov_len = 4096;
	vecs[1].iov_base = p1 + 4096;
	vecs[1].iov_len = 4096;

	tags[0] = 1;
	tags[1] = 2;
	ret = io_uring_register_buffers_update_tag(&ring, 4, vecs, tags, 2);
	if (ret < 0) {
		if (ret == -EINVAL)
			goto skip;
		fprintf(stderr, "failed to register merge buffers: %d\n", ret);
		return T_EXIT_FAIL;
	}
	res = T_EXIT_PASS;
skip:
	munmap(p1, 2*1024*1024);
	io_uring_queue_exit(&ring);
	return res;
}

static int test_same(void)
{