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[34.145.139.141]) by smtp.gmail.com with UTF8SMTPSA id 6a1803df08f44-6f4c0a73c83sm63586026d6.92.2025.04.28.11.20.22 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 28 Apr 2025 11:20:22 -0700 (PDT) Date: Mon, 28 Apr 2025 14:20:21 -0400 From: Willem de Bruijn To: Martin Karsten , Willem de Bruijn , Samiullah Khawaja , Jakub Kicinski , "David S . Miller" , Eric Dumazet , Paolo Abeni , almasrymina@google.com, willemb@google.com, jdamato@fastly.com Cc: netdev@vger.kernel.org Message-ID: <680fc6e5cc652_247f7d294a2@willemb.c.googlers.com.notmuch> In-Reply-To: References: <20250424200222.2602990-1-skhawaja@google.com> <52e7cf72-6655-49ed-984c-44bd1ecb0d95@uwaterloo.ca> <680fb23bb1953_23f881294d9@willemb.c.googlers.com.notmuch> Subject: Re: [PATCH net-next v5 0/4] Add support to do threaded napi busy poll Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit Martin Karsten wrote: > On 2025-04-28 12:52, Willem de Bruijn wrote: > > Martin Karsten wrote: > >> On 2025-04-24 16:02, Samiullah Khawaja wrote: > > [snip] > > > There is also a functional argument for this feature. It brings > > parity with userspace network stacks like DPDK and Google's SNAP [1]. > > These also run packet (and L4+) network processing on dedicated cores, > > and by default do so in polling mode. An XDP plane currently lacks > > this well understood configuration. This brings it closer to parity. > I believe these existing user-level stacks burn one core per queue. This > scheme burns two. That's specific to the AF_XDP use-case where AF_XDP also runs in polling mode. There are other use cases that more closely match DPDK, such as an XDP dataplane. Conversely, DPDK with reinject into the host kernel will also have to handle the signal or polling of the second stage.