On 2021/1/16 上午10:59, Xuan Zhuo wrote:
XDP socket is an excellent by pass kernel network transmission framework. The zero copy feature of xsk (XDP socket) needs to be supported by the driver. The performance of zero copy is very good. mlx5 and intel ixgbe already support this feature, This patch set allows virtio-net to support xsk's zerocopy xmit feature. And xsk's zerocopy rx has made major changes to virtio-net, and I hope to submit it after this patch set are received. Compared with other drivers, virtio-net does not directly obtain the dma address, so I first obtain the xsk page, and then pass the page to virtio. When recycling the sent packets, we have to distinguish between skb and xdp. Now we have to distinguish between skb, xdp, xsk. So the second patch solves this problem first. The last four patches are used to support xsk zerocopy in virtio-net: 1. support xsk enable/disable 2. realize the function of xsk packet sending 3. implement xsk wakeup callback 4. set xsk completed when packet sent done ---------------- Performance Testing ------------ The udp package tool implemented by the interface of xsk vs sockperf(kernel udp) for performance testing: xsk zero copy in virtio-net: CPU PPS MSGSIZE 28.7% 3833857 64 38.5% 3689491 512 38.9% 2787096 1456
Some questions on the results: 1) What's the setup on the vhost? 2) What's the setup of the mitigation in both host and guest? 3) Any analyze on the possible bottleneck via perf or other tools? Thanks
xsk without zero copy in virtio-net: CPU PPS MSGSIZE 100% 1916747 64 100% 1775988 512 100% 1440054 1456 sockperf: CPU PPS MSGSIZE 100% 713274 64 100% 701024 512 100% 695832 1456 Xuan Zhuo (7): xsk: support get page for drv virtio-net, xsk: distinguish XDP_TX and XSK XMIT ctx xsk, virtio-net: prepare for support xsk zerocopy xmit virtio-net, xsk: support xsk enable/disable virtio-net, xsk: realize the function of xsk packet sending virtio-net, xsk: implement xsk wakeup callback virtio-net, xsk: set xsk completed when packet sent done drivers/net/virtio_net.c | 559 +++++++++++++++++++++++++++++++++++++++----- include/linux/netdevice.h | 1 + include/net/xdp_sock_drv.h | 10 + include/net/xsk_buff_pool.h | 1 + net/xdp/xsk_buff_pool.c | 10 +- 5 files changed, 523 insertions(+), 58 deletions(-) -- 1.8.3.1
