From: Simon Schippers <simon.schippers@tu-dortmund.de>
To: willemdebruijn.kernel@gmail.com, jasowangio@gmail.com,
jasowang@redhat.com, andrew+netdev@lunn.ch, davem@davemloft.net,
edumazet@google.com, kuba@kernel.org, pabeni@redhat.com,
horms@kernel.org, mst@redhat.com, eperezma@redhat.com,
leiyang@redhat.com, stephen@networkplumber.org, jon@nutanix.com,
brett@librecast.net, corbet@lwn.net, skhan@linuxfoundation.org,
tim.gebauer@tu-dortmund.de, netdev@vger.kernel.org,
linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org,
kvm@vger.kernel.org, virtualization@lists.linux.dev
Subject: Re: [PATCH net-next v14 0/5] tun/tap & vhost-net: apply qdisc backpressure on full ptr_ring to reduce TX drops
Date: Wed, 5 Aug 2026 07:20:26 +0200 [thread overview]
Message-ID: <0e3efa4a-e9bb-4e98-8b1f-1a8637c429db@tu-dortmund.de> (raw)
In-Reply-To: <20260803183641.96882-1-simon.schippers@tu-dortmund.de>
On 8/3/26 20:36, Simon Schippers wrote:
> This patch series deals with tun/tap & vhost-net which drop incoming
> SKBs whenever their internal ptr_ring buffer is full. Instead, with this
> patch series, the associated netdev queue is stopped, but only when the
> new IFF_BACKPRESSURE flag is set and a qdisc is attached. Without the
> flag, or if no qdisc is present, the existing behavior is preserved. The
> XDP transmit path is not affected. This patch series touches tun/tap and
> vhost-net, as they share common logic and must be updated together.
> Modifying only one of them would break the other.
>
Sashiko is happy now.
Gemini reports in patch 2:
"[Severity: Medium]
Will vhost-net bypass this wrapper and cause permanent TX queue stalls when
IFF_BACKPRESSURE is enabled?"
... but this is added in patch 3. It just cant cross-reference it.
So it is fine.
next prev parent reply other threads:[~2026-08-05 5:23 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-08-03 18:36 [PATCH net-next v14 0/5] tun/tap & vhost-net: apply qdisc backpressure on full ptr_ring to reduce TX drops Simon Schippers
2026-08-03 18:36 ` [PATCH net-next v14 1/5] tun/tap: add IFF_BACKPRESSURE flag Simon Schippers
2026-08-03 18:36 ` [PATCH net-next v14 2/5] tun/tap: add ptr_ring consume helper with netdev queue wakeup Simon Schippers
2026-08-03 18:36 ` [PATCH net-next v14 3/5] vhost-net: wake queue of tun/tap after ptr_ring consume Simon Schippers
2026-08-03 18:36 ` [PATCH net-next v14 4/5] ptr_ring: move free-space check into separate helper Simon Schippers
2026-08-03 18:36 ` [PATCH net-next v14 5/5] tun/tap & vhost-net: stop tail-drop when IFF_BACKPRESSURE is set Simon Schippers
2026-08-05 5:20 ` Simon Schippers [this message]
2026-08-08 1:10 ` [PATCH net-next v14 0/5] tun/tap & vhost-net: apply qdisc backpressure on full ptr_ring to reduce TX drops patchwork-bot+netdevbpf
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