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* [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

end of thread, other threads:[~2025-07-09  9:31 UTC | newest]

Thread overview: 3+ messages (download: mbox.gz / follow: Atom feed)
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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

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