From: David Gibson <david@gibson.dropbear.id.au>
To: Laurent Vivier <lvivier@redhat.com>
Cc: passt-dev@passt.top
Subject: Re: [PATCH 02/12] vhost-user: Use ARRAY_SIZE(elem) instead of VIRTQUEUE_MAX_SIZE
Date: Mon, 2 Mar 2026 10:48:34 +1100 [thread overview]
Message-ID: <aaTQUvNOMzaceq7k@zatzit> (raw)
In-Reply-To: <20260227140330.2216753-3-lvivier@redhat.com>
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On Fri, Feb 27, 2026 at 03:03:20PM +0100, Laurent Vivier wrote:
> When passing the element count to vu_init_elem(), vu_collect(), or using
> it as a loop bound, use ARRAY_SIZE(elem) instead of the VIRTQUEUE_MAX_SIZE.
>
> No functional change.
>
> Signed-off-by: Laurent Vivier <lvivier@redhat.com>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
> ---
> tcp_vu.c | 6 +++---
> udp_vu.c | 4 ++--
> vu_common.c | 6 +++---
> 3 files changed, 8 insertions(+), 8 deletions(-)
>
> diff --git a/tcp_vu.c b/tcp_vu.c
> index bb05fbf45826..98e5974fee0e 100644
> --- a/tcp_vu.c
> +++ b/tcp_vu.c
> @@ -201,17 +201,17 @@ static ssize_t tcp_vu_sock_recv(const struct ctx *c, struct vu_virtq *vq,
>
> hdrlen = tcp_vu_hdrlen(v6);
>
> - vu_init_elem(elem, &iov_vu[DISCARD_IOV_NUM], VIRTQUEUE_MAX_SIZE);
> + vu_init_elem(elem, &iov_vu[DISCARD_IOV_NUM], ARRAY_SIZE(elem));
>
> elem_cnt = 0;
> *head_cnt = 0;
> - while (fillsize > 0 && elem_cnt < VIRTQUEUE_MAX_SIZE) {
> + while (fillsize > 0 && elem_cnt < ARRAY_SIZE(elem)) {
> struct iovec *iov;
> size_t frame_size, dlen;
> int cnt;
>
> cnt = vu_collect(vdev, vq, &elem[elem_cnt],
> - VIRTQUEUE_MAX_SIZE - elem_cnt,
> + ARRAY_SIZE(elem) - elem_cnt,
> MAX(MIN(mss, fillsize) + hdrlen, ETH_ZLEN + VNET_HLEN),
> &frame_size);
> if (cnt == 0)
> diff --git a/udp_vu.c b/udp_vu.c
> index 51f3718f5925..6f6477f7d046 100644
> --- a/udp_vu.c
> +++ b/udp_vu.c
> @@ -89,9 +89,9 @@ static int udp_vu_sock_recv(const struct ctx *c, struct vu_virtq *vq, int s,
> /* compute L2 header length */
> hdrlen = udp_vu_hdrlen(v6);
>
> - vu_init_elem(elem, iov_vu, VIRTQUEUE_MAX_SIZE);
> + vu_init_elem(elem, iov_vu, ARRAY_SIZE(elem));
>
> - iov_cnt = vu_collect(vdev, vq, elem, VIRTQUEUE_MAX_SIZE,
> + iov_cnt = vu_collect(vdev, vq, elem, ARRAY_SIZE(elem),
> IP_MAX_MTU + ETH_HLEN + VNET_HLEN, NULL);
> if (iov_cnt == 0)
> return -1;
> diff --git a/vu_common.c b/vu_common.c
> index aa14598ea028..7a8cd18f4e81 100644
> --- a/vu_common.c
> +++ b/vu_common.c
> @@ -174,7 +174,7 @@ static void vu_handle_tx(struct vu_dev *vdev, int index,
>
> count = 0;
> out_sg_count = 0;
> - while (count < VIRTQUEUE_MAX_SIZE &&
> + while (count < ARRAY_SIZE(elem) &&
> out_sg_count + VU_MAX_TX_BUFFER_NB <= VIRTQUEUE_MAX_SIZE) {
> int ret;
> struct iov_tail data;
> @@ -259,10 +259,10 @@ int vu_send_single(const struct ctx *c, const void *buf, size_t size)
> return -1;
> }
>
> - vu_init_elem(elem, in_sg, VIRTQUEUE_MAX_SIZE);
> + vu_init_elem(elem, in_sg, ARRAY_SIZE(elem));
>
> size += VNET_HLEN;
> - elem_cnt = vu_collect(vdev, vq, elem, VIRTQUEUE_MAX_SIZE, size, &total);
> + elem_cnt = vu_collect(vdev, vq, elem, ARRAY_SIZE(elem), size, &total);
> if (total < size) {
> debug("vu_send_single: no space to send the data "
> "elem_cnt %d size %zd", elem_cnt, total);
> --
> 2.53.0
>
--
David Gibson (he or they) | I'll have my music baroque, and my code
david AT gibson.dropbear.id.au | minimalist, thank you, not the other way
| around.
http://www.ozlabs.org/~dgibson
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next prev parent reply other threads:[~2026-03-02 0:13 UTC|newest]
Thread overview: 25+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-02-27 14:03 [PATCH 00/12] vhost-user,udp: Handle multiple iovec entries per virtqueue element Laurent Vivier
2026-02-27 14:03 ` [PATCH 01/12] iov: Add iov_tail_truncate() and iov_tail_zero_end() Laurent Vivier
2026-03-01 23:47 ` David Gibson
2026-02-27 14:03 ` [PATCH 02/12] vhost-user: Use ARRAY_SIZE(elem) instead of VIRTQUEUE_MAX_SIZE Laurent Vivier
2026-03-01 23:48 ` David Gibson [this message]
2026-02-27 14:03 ` [PATCH 03/12] udp_vu: Use iov_tail to manage virtqueue buffers Laurent Vivier
2026-03-02 0:03 ` David Gibson
2026-02-27 14:03 ` [PATCH 04/12] udp_vu: Move virtqueue management from udp_vu_sock_recv() to its caller Laurent Vivier
2026-03-02 0:05 ` David Gibson
2026-02-27 14:03 ` [PATCH 05/12] iov: Add IOV_PUT_HEADER() to write header data back to iov_tail Laurent Vivier
2026-03-02 0:08 ` David Gibson
2026-02-27 14:03 ` [PATCH 06/12] udp: Pass iov_tail to udp_update_hdr4()/udp_update_hdr6() Laurent Vivier
2026-03-02 0:13 ` David Gibson
2026-02-27 14:03 ` [PATCH 07/12] udp_vu: Use iov_tail in udp_vu_prepare() Laurent Vivier
2026-03-02 0:24 ` David Gibson
2026-02-27 14:03 ` [PATCH 08/12] vu_common: Pass iov_tail to vu_set_vnethdr() Laurent Vivier
2026-03-02 0:51 ` David Gibson
2026-02-27 14:03 ` [PATCH 09/12] vu_common: Accept explicit iovec counts in vu_set_element() Laurent Vivier
2026-03-02 0:54 ` David Gibson
2026-02-27 14:03 ` [PATCH 10/12] vu_common: Accept explicit iovec count per element in vu_init_elem() Laurent Vivier
2026-03-02 0:55 ` David Gibson
2026-02-27 14:03 ` [PATCH 11/12] vu_common: Prepare to use multibuffer with guest RX Laurent Vivier
2026-03-02 0:59 ` David Gibson
2026-02-27 14:03 ` [PATCH 12/12] vhost-user,udp: Use 2 iovec entries per element Laurent Vivier
2026-03-02 1:03 ` David Gibson
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