On Wed, 4 Feb 2026 08:12:02 -0800 [email protected] wrote: > From: Scott <[email protected]> > > When user space application does sendto() to notify the kernel > there is data to process, the kernel synchronously processes > pending frames and the CPU cost is attributed to the application. > The kernel processing may also include kernel RX (netlink, ovs) > and packet manipulation. This can negatively impact performance > by limiting CPU to each dpdk network thread. > > io_uring offers a mode (SQPOLL) to offload this processing > to a dedicated kernel thread. This makes the kernel processing > asynchronous, which can improve throughput by 30%+. The trade-off > is SQPOLL threads consume additional CPU but this follows the > same principle as virtio backends, and enables use cases that > can't adopt virtio (e.g. containerized workloads). > > This patch adds optional io_uring support for TX kick operations > to replace synchronous sendto() syscalls. When enabled, uses > SQPOLL mode with kernel-side submission polling for reduced > syscall overhead. > > Features: > - Optional liburing dependency (version >= 2.4 required) > - SQPOLL mode with configurable idle timeout > - CPU affinity for SQPOLL threads (IORING_SETUP_SQ_AFF) > - Shared workqueue support (IORING_SETUP_ATTACH_WQ) > - Registered file descriptors for IOSQE_FIXED_FILE optimization > - Single issuer and cooperative taskrun optimizations when available > > New devargs: > - tx_io_uring_enabled: Enable io_uring TX (default: 0) > - tx_io_uring_sq_size: Submission queue size (default: 1024) > - tx_io_uring_sq_thread_idle: SQPOLL idle timeout in ms (default: 500) > - tx_io_uring_q_cpu: CPU affinity for SQPOLL threads (repeatable) > - tx_io_uring_wq_num: Number of shared workqueues (default: 0) > > The TX path updates the ring tail pointer directly instead of calling > io_uring_submit() to avoid the io_uring_enter syscall, relying on > SQPOLL to pick up submissions. If the SQPOLL thread sleeps, we wake > it with IORING_ENTER_SQ_WAKEUP. > > Falls back gracefully to sendto() when: > - liburing is not available at compile time > - SQPOLL is not supported by the kernel > - io_uring initialization fails for any reason > > Signed-off-by: Scott <[email protected]> > --- > Depends-on: series-37248 ("af_packet correctness, performance, cksum") > > doc/guides/nics/af_packet.rst | 16 +- > doc/guides/rel_notes/release_26_03.rst | 1 + > drivers/net/af_packet/meson.build | 14 + > drivers/net/af_packet/rte_eth_af_packet.c | 420 +++++++++++++++++++++- > 4 files changed, 435 insertions(+), 16 deletions(-) > > diff --git a/doc/guides/nics/af_packet.rst b/doc/guides/nics/af_pac
I would rather it be a different driver than af_packet. See my RFC patch for using io_uring
