From 2038f185309c49e95e93d4ddd30145ece2039be3 Mon Sep 17 00:00:00 2001 From: Jens Axboe Date: Wed, 18 Oct 2023 08:53:05 -0600 Subject: [PATCH] man/io_uring_setup_buf_ring.3: add note about highmem and 32-bit Signed-off-by: Jens Axboe --- man/io_uring_setup_buf_ring.3 | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-) diff --git a/man/io_uring_setup_buf_ring.3 b/man/io_uring_setup_buf_ring.3 index 2a9dd8666..18265687e 100644 --- a/man/io_uring_setup_buf_ring.3 +++ b/man/io_uring_setup_buf_ring.3 @@ -63,11 +63,17 @@ Available since 5.19. .SH RETURN VALUE On success .BR io_uring_setup_buf_ring (3) -returns a pointer to the buffe ring. On failure it returns +returns a pointer to the buffer ring. On failure it returns .BR NULL and sets .I *ret to -errno. +.SH NOTES +Note that even if the kernel supports this feature, registering a provided +buffer ring may still fail with +.B -EINVAL +if the host is a 32-bit architecture and the memory being passed in resides in +high memory. .SH SEE ALSO .BR io_uring_register_buf_ring (3), .BR io_uring_buf_ring_init (3),