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[80.230.35.22]) by smtp.gmail.com with ESMTPSA id ffacd0b85a97d-432bd5ee5e3sm35982021f8f.35.2026.01.11.20.33.12 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Sun, 11 Jan 2026 20:33:14 -0800 (PST) Date: Sun, 11 Jan 2026 23:33:10 -0500 From: "Michael S. Tsirkin" To: Simon Schippers Cc: Jason Wang , willemdebruijn.kernel@gmail.com, andrew+netdev@lunn.ch, davem@davemloft.net, edumazet@google.com, kuba@kernel.org, pabeni@redhat.com, eperezma@redhat.com, leiyang@redhat.com, stephen@networkplumber.org, jon@nutanix.com, tim.gebauer@tu-dortmund.de, netdev@vger.kernel.org, linux-kernel@vger.kernel.org, kvm@vger.kernel.org, virtualization@lists.linux.dev Subject: Re: [PATCH net-next v7 9/9] tun/tap & vhost-net: avoid ptr_ring tail-drop when qdisc is present Message-ID: <20260111233129-mutt-send-email-mst@kernel.org> References: <20260107210448.37851-1-simon.schippers@tu-dortmund.de> <20260107210448.37851-10-simon.schippers@tu-dortmund.de> <900c364b-f5ca-4458-a711-bf3e0433b537@tu-dortmund.de> Precedence: bulk X-Mailing-List: virtualization@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 In-Reply-To: <900c364b-f5ca-4458-a711-bf3e0433b537@tu-dortmund.de> X-Mimecast-Spam-Score: 0 X-Mimecast-MFC-PROC-ID: naN3ZruAG5VTd05JcmOwBwW3dw7kC-CoCzUMlX6Px1A_1768192396 X-Mimecast-Originator: redhat.com Content-Type: text/plain; charset=us-ascii Content-Disposition: inline On Fri, Jan 09, 2026 at 11:14:54AM +0100, Simon Schippers wrote: > Am I not allowed to stop the queue and then return NETDEV_TX_BUSY? We jump through a lot of hoops in virtio_net to avoid using NETDEV_TX_BUSY because that bypasses all the net/ cleverness. Given your patches aim to improve precisely ring full, I would say stopping proactively before NETDEV_TX_BUSY should be a priority. -- MST