On Thu, Feb 13, 2020 at 5:00 PM Yi Yang (杨燚)-云服务集团 <[email protected]> wrote: > > No, block size and frame size are defined by user, you can specify any size, > but block size must be pagesize aligned, please read v3 patch and try it in > your environment. >
Right, but How do we set block size and frame size to accommodate the TSO 64K-size packet? William > -----邮件原件----- > 发件人: William Tu [mailto:[email protected]] > 发送时间: 2020年2月14日 8:38 > 收件人: Ilya Maximets <[email protected]> > 抄送: [email protected]; ovs-dev <[email protected]>; yang_y_yi > <[email protected]>; Ben Pfaff <[email protected]>; Yi Yang (杨燚)-云服务集团 > <[email protected]> > 主题: Re: [ovs-dev] [PATCH v2] Use TPACKET_V3 to accelerate veth for userspace > datapath > > On Fri, Feb 7, 2020 at 6:43 AM Ilya Maximets <[email protected]> wrote: > > > > On 2/7/20 12:50 PM, [email protected] wrote: > > > From: Yi Yang <[email protected]> > > > > > > We can avoid high system call overhead by using TPACKET_V3 and using > > > DPDK-like poll to receive and send packets (Note: send still needs > > > to call sendto to trigger final packet transmission). > > > > > >>From Linux kernel 3.10 on, TPACKET_V3 has been supported, > > > so all the Linux kernels current OVS supports can run > > > TPACKET_V3 without any problem. > > > > > > I can see about 30% performance improvement for veth compared to > > > last recvmmsg optimization if I use TPACKET_V3, it is about 1.98 > > > Gbps, but it was 1.47 Gbps before. > > > > > > Note: it can't support TSO which is in progress. > > > > So, this patch effectively breaks TSO functionality in compile time, > > i.e. it compiles out the TSO capable function invocation. > > I don't think that we should mege that. For this patch to be > > acceptable, tpacket implementation should support TSO or it should be > > possible to dynamically switch to usual sendmmsg if we want to enable TSO > > support. > > > I think it's impossible to support tpacket + TSO, because tpacket > pre-allocate a ring buffer with 2K buffer size, and each descriptor can only > point to one entry. > (If I understand correctly) > > So I think we should dynamically switch back to sendmmsg when TSO is enabled. > > Regards, > William _______________________________________________ dev mailing list [email protected] https://mail.openvswitch.org/mailman/listinfo/ovs-dev
