[dpdk-dev] [RFC 0/7] PMD driver for AF_XDP

[Zhang, Qi Z]

+Magnus, since a typo in my first batch in email address.

> -----Original Message-----
> From: dev [mailto:dev-bounces at dpdk.org] On Behalf Of Zhang, Qi Z
> Sent: Thursday, March 1, 2018 12:19 PM
> To: Jason Wang <jasowang at redhat.com>; dev at dpdk.org
> Cc: magnus.karlsson at intei.com; Topel, Bjorn <bjorn.topel at intel.com>
> Subject: Re: [dpdk-dev] [RFC 0/7] PMD driver for AF_XDP
> 
> 
> 
> > -----Original Message-----
> > From: Jason Wang [mailto:jasowang at redhat.com]
> > Sent: Thursday, March 1, 2018 10:52 AM
> > To: Zhang, Qi Z <qi.z.zhang at intel.com>; dev at dpdk.org
> > Cc: magnus.karlsson at intei.com; Topel, Bjorn <bjorn.topel at intel.com>
> > Subject: Re: [dpdk-dev] [RFC 0/7] PMD driver for AF_XDP
> >
> >
> >
> > On 2018年02月27日 17:32, Qi Zhang wrote:
> > > The RFC patches add a new PMD driver for AF_XDP which is a proposed
> > > faster version of AF_PACKET interface in Linux, see below link for
> > > detail AF_XDP introduction:
> > > https://fosdem.org/2018/schedule/event/af_xdp/
> > > https://lwn.net/Articles/745934/
> > >
> > > This patchset is base on v18.02.
> > > It also require a linux kernel that have below AF_XDP RFC patches be
> > > applied.
> > > https://patchwork.ozlabs.org/patch/867961/
> > > https://patchwork.ozlabs.org/patch/867960/
> > > https://patchwork.ozlabs.org/patch/867938/
> > > https://patchwork.ozlabs.org/patch/867939/
> > > https://patchwork.ozlabs.org/patch/867940/
> > > https://patchwork.ozlabs.org/patch/867941/
> > > https://patchwork.ozlabs.org/patch/867942/
> > > https://patchwork.ozlabs.org/patch/867943/
> > > https://patchwork.ozlabs.org/patch/867944/
> > > https://patchwork.ozlabs.org/patch/867945/
> > > https://patchwork.ozlabs.org/patch/867946/
> > > https://patchwork.ozlabs.org/patch/867947/
> > > https://patchwork.ozlabs.org/patch/867948/
> > > https://patchwork.ozlabs.org/patch/867949/
> > > https://patchwork.ozlabs.org/patch/867950/
> > > https://patchwork.ozlabs.org/patch/867951/
> > > https://patchwork.ozlabs.org/patch/867952/
> > > https://patchwork.ozlabs.org/patch/867953/
> > > https://patchwork.ozlabs.org/patch/867954/
> > > https://patchwork.ozlabs.org/patch/867955/
> > > https://patchwork.ozlabs.org/patch/867956/
> > > https://patchwork.ozlabs.org/patch/867957/
> > > https://patchwork.ozlabs.org/patch/867958/
> > > https://patchwork.ozlabs.org/patch/867959/
> > >
> > > There is no clean upstream target yet since kernel patch is still in
> > > RFC stage, The purpose of the patchset is just for anyone that want
> > > to eveluate af_xdp with DPDK application and get feedback for
> > > further improvement.
> > >
> > > To try with the new PMD
> > > 1. compile and install the kernel with above patches applied.
> > > 2. configure $LINUX_HEADER_DIR (dir of "make headers_install")
> > >     and $TOOLS_DIR (dir at <kernel_src>/tools) at
> > driver/net/af_xdp/Makefile
> > >     before compile DPDK.
> > > 3. make sure libelf and libbpf is installed.
> > >
> > > BTW, performance test shows our PMD can reach 94%~98% of the orignal
> > > benchmark when share memory is enabled.
> >
> > Hi:
> >
> > Looks like zero copy is not used in this series. Any plan to support that?
> 
> Zero copy is enabled in patch 5, if a mempool passed check_mempool, it will
> be registered to af_xdp socket.
> so there will be no memcpy between mbuf and af_xdp.
> 
> > If not, what's the advantage compared to vhost-net + tap + XDP_REDIRECT?
> >
> > Have you measured l2fwd performance in this case? I believe the number
> > you refer here is rxdrop (XDP_DRV) which is 11.6Mpps.
> 
> Actually we measure the performance on rxonly / txonly / l2fwd on i40e with
> XDP_SKB and XDP_DRV_ZC
> 
> Regards
> Qi
> 
> >
> > Thanks