Thanks William, https://www.kernel.org/doc/Documentation/networking/packet_mmap.txt is very good document for TPACKET_V*, I completely agree TPCKET_V3 is the best way to improve tap and veth performance. Can you share us how to use your patch? Lib/netdev-linux.c is still there, which recv function will be called when I add veth/tap in OVS DPDK?
-----邮件原件----- 发件人: William Tu [mailto:u9012...@gmail.com] 发送时间: 2019年12月21日 1:43 收件人: Yi Yang (杨燚)-云服务集团 <yangy...@inspur.com> 抄送: d...@openvswitch.org; i.maxim...@ovn.org; b...@ovn.org; echau...@redhat.com 主题: Re: 答复: [PATCH RFC] WIP: netdev-tpacket: Add AF_PACKET v3 support. On Fri, Dec 20, 2019 at 06:09:08AM +0000, Yi Yang (杨燚)-云服务集团 wrote: > Hi, William > > What kernel version can support AF_PACKET v3? I can try it with your patch. Hi Yiyang, Kernel +4.0 should have v3 support. I'm also reading this doc: https://www.kernel.org/doc/Documentation/networking/packet_mmap.txt ------------------------------------------------------------------------------- + AF_PACKET TPACKET_V3 example ------------------------------------------------------------------------------- AF_PACKET's TPACKET_V3 ring buffer can be configured to use non-static frame sizes by doing it's own memory management. It is based on blocks where polling works on a per block basis instead of per ring as in TPACKET_V2 and predecessor. It is said that TPACKET_V3 brings the following benefits: *) ~15 - 20% reduction in CPU-usage *) ~20% increase in packet capture rate *) ~2x increase in packet density *) Port aggregation analysis *) Non static frame size to capture entire packet payload So it seems to be a good candidate to be used with packet fanout. DPDK library is using TPACKET_V2, and V3 is better due to: TPACKET_V2 --> TPACKET_V3: - Flexible buffer implementation for RX_RING: 1. Blocks can be configured with non-static frame-size 2. Read/poll is at a block-level (as opposed to packet-level) 3. Added poll timeout to avoid indefinite user-space wait on idle links 4. Added user-configurable knobs: 4.1 block::timeout 4.2 tpkt_hdr::sk_rxhash - RX Hash data available in user space - TX_RING semantics are conceptually similar to TPACKET_V2; Thanks William > > -----邮件原件----- > 发件人: William Tu [mailto:u9012...@gmail.com] > 发送时间: 2019年12月20日 8:41 > 收件人: d...@openvswitch.org > 抄送: i.maxim...@ovn.org; Yi Yang (杨燚)-云服务集团 <yangy...@inspur.com>; > b...@ovn.org; echau...@redhat.com > 主题: [PATCH RFC] WIP: netdev-tpacket: Add AF_PACKET v3 support. > > Currently the performance of sending packets from userspace ovs to > kernel veth device is pretty bad as reported from YiYang[1]. > The patch adds AF_PACKET v3, tpacket v3, as another way to tx/rx > packet to linux device, hopefully showing better performance. > > AF_PACKET v3 should get closed to 1Mpps, as shown[2]. However, my > current patch using iperf tcp shows only 1.4Gbps, maybe I'm doing something > wrong. > Also DPDK has similar implementation using AF_PACKET v2[3]. This is > still work-in-progress but any feedbacks are welcome. > > [1] https://patchwork.ozlabs.org/patch/1204939/ > [2] slide 18, https://www.netdevconf.info/2.2/slides/karlsson-afpacket-talk. > pdf > [3] dpdk/drivers/net/af_packet/rte_eth_af_packet.c > --- > lib/automake.mk | 2 + > lib/netdev-linux-private.h | 23 +++ > lib/netdev-linux.c | 24 ++- > lib/netdev-provider.h | 1 + > lib/netdev-tpacket.c | 487 > +++++++++++++++++++++++++++++++++++++++++++++ > lib/netdev-tpacket.h | 43 ++++ > lib/netdev.c | 1 + > 7 files changed, 580 insertions(+), 1 deletion(-) create mode 100644 > lib/netdev-tpacket.c create mode 100644 lib/netdev-tpacket.h > _______________________________________________ dev mailing list d...@openvswitch.org https://mail.openvswitch.org/mailman/listinfo/ovs-dev
