* [PATCH] net/virtio: revert Tx free threshold fix
@ 2025-07-08 14:23 David Marchand
2025-07-09 1:34 ` Hengqi Chen
0 siblings, 1 reply; 3+ messages in thread
From: David Marchand @ 2025-07-08 14:23 UTC (permalink / raw)
To: dev; +Cc: thomas, stable, Maxime Coquelin, Chenbo Xia, Hengqi Chen, Baoyuan Li
This fix introduced a performance regression.
The problem is under investigation, but we are too close to the release
(and the virtio/vhost maintainer is not available) to get a fix before
the v25.07 release.
Revert this change for now, we can revisit during v25.11.
Bugzilla ID: 1747
Fixes: 3e3c7f3fa5ac ("net/virtio: fix check of threshold for Tx freeing")
Cc: stable@dpdk.org
Signed-off-by: David Marchand <david.marchand@redhat.com>
---
drivers/net/virtio/virtio_rxtx.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/net/virtio/virtio_rxtx.c b/drivers/net/virtio/virtio_rxtx.c
index ab97f03d7d..edecd2011f 100644
--- a/drivers/net/virtio/virtio_rxtx.c
+++ b/drivers/net/virtio/virtio_rxtx.c
@@ -1873,7 +1873,7 @@ virtio_xmit_pkts(void *tx_queue, struct rte_mbuf **tx_pkts, uint16_t nb_pkts)
nb_used = virtqueue_nused(vq);
- if (likely(vq->vq_free_cnt < vq->vq_free_thresh))
+ if (likely(nb_used > vq->vq_nentries - vq->vq_free_thresh))
virtio_xmit_cleanup(vq, nb_used);
for (nb_tx = 0; nb_tx < nb_pkts; nb_tx++) {
--
2.50.0
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [PATCH] net/virtio: revert Tx free threshold fix
2025-07-08 14:23 [PATCH] net/virtio: revert Tx free threshold fix David Marchand
@ 2025-07-09 1:34 ` Hengqi Chen
2025-07-09 9:31 ` David Marchand
0 siblings, 1 reply; 3+ messages in thread
From: Hengqi Chen @ 2025-07-09 1:34 UTC (permalink / raw)
To: David Marchand
Cc: dev, thomas, stable, Maxime Coquelin, Chenbo Xia, Baoyuan Li
On Tue, Jul 8, 2025 at 10:23 PM David Marchand
<david.marchand@redhat.com> wrote:
>
> This fix introduced a performance regression.
>
> The problem is under investigation, but we are too close to the release
> (and the virtio/vhost maintainer is not available) to get a fix before
> the v25.07 release.
>
> Revert this change for now, we can revisit during v25.11.
>
Acked-by: Hengqi Chen <hengqi.chen@gmail.com>
> Bugzilla ID: 1747
> Fixes: 3e3c7f3fa5ac ("net/virtio: fix check of threshold for Tx freeing")
> Cc: stable@dpdk.org
>
> Signed-off-by: David Marchand <david.marchand@redhat.com>
> ---
> drivers/net/virtio/virtio_rxtx.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/net/virtio/virtio_rxtx.c b/drivers/net/virtio/virtio_rxtx.c
> index ab97f03d7d..edecd2011f 100644
> --- a/drivers/net/virtio/virtio_rxtx.c
> +++ b/drivers/net/virtio/virtio_rxtx.c
> @@ -1873,7 +1873,7 @@ virtio_xmit_pkts(void *tx_queue, struct rte_mbuf **tx_pkts, uint16_t nb_pkts)
>
> nb_used = virtqueue_nused(vq);
>
> - if (likely(vq->vq_free_cnt < vq->vq_free_thresh))
> + if (likely(nb_used > vq->vq_nentries - vq->vq_free_thresh))
> virtio_xmit_cleanup(vq, nb_used);
>
> for (nb_tx = 0; nb_tx < nb_pkts; nb_tx++) {
> --
> 2.50.0
>
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [PATCH] net/virtio: revert Tx free threshold fix
2025-07-09 1:34 ` Hengqi Chen
@ 2025-07-09 9:31 ` David Marchand
0 siblings, 0 replies; 3+ messages in thread
From: David Marchand @ 2025-07-09 9:31 UTC (permalink / raw)
To: David Marchand
Cc: dev, thomas, stable, Maxime Coquelin, Chenbo Xia, Baoyuan Li,
Hengqi Chen
On Wed, Jul 9, 2025 at 3:34 AM Hengqi Chen <hengqi.chen@gmail.com> wrote:
>
> On Tue, Jul 8, 2025 at 10:23 PM David Marchand
> <david.marchand@redhat.com> wrote:
> >
> > This fix introduced a performance regression.
> >
> > The problem is under investigation, but we are too close to the release
> > (and the virtio/vhost maintainer is not available) to get a fix before
> > the v25.07 release.
> >
> > Revert this change for now, we can revisit during v25.11.
> >
> > Bugzilla ID: 1747
> > Fixes: 3e3c7f3fa5ac ("net/virtio: fix check of threshold for Tx freeing")
> > Cc: stable@dpdk.org
> >
> > Signed-off-by: David Marchand <david.marchand@redhat.com>
> Acked-by: Hengqi Chen <hengqi.chen@gmail.com>
Applied, thanks.
--
David Marchand
^ permalink raw reply [flat|nested] 3+ messages in thread
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