On Fri, 18 Jun 2021 19:40:17 +0200 Jesper Dangaard Brouer <brouer@xxxxxxxxxx> wrote: > On Fri, 18 Jun 2021 13:31:06 -0300 > "Ethy H. Brito" <ethy.brito@xxxxxxxxxxxx> wrote: > > > Hi All. > > > > I've been doing some home work reading the docs and some doubts have raised. > > For reference, my environment is > > Ubuntu 20.04 > > kernel 5.4.0-66 > > tc utility, iproute2-ss200127. > > > > 1) https://xdp-project.net/areas/cpumap.html#cpumap--Create-script-MQ-HTB-silo-setup says that: > > "XPS (Transmit Packet Steering) will take precedence over any changes to > > skb->queue_mapping. You need to disable *XDP* via mask=00 in files > > /sys/class/net/DEV/queues/tx-*/xps_cpus" > > > > Shouldn't it say I need to disable *XPS* (not XDP) using mask=00?? > > You are absolutely right it is a typo. Can I ask you to fix that and > send a GitHub PR? > > The file you need to change is: > https://github.com/xdp-project/xdp-project/blob/master/areas/cpumap.org > I'll have to figure it out how to do that. Never edited a GitHub before. > > > 2) Taking tc_mq_htb_setup_example.sh as reference, how to enable XDP? > > XDP gets enabled when you load an XDP program. Ok. > > > Since I have to disable XPS, I assume I have to enable something in > > replacement, right? > > No, XPS is just a kernel feature you need to disable, because it > conflicts with the TC-BPF program usage of skb->queue_mapping. Pretty advanced topic. But I'll get there. > > > > How to set that CPU-0 will deal with mq queue 7FFF:1, CPU-1 will deal > > with 7FFF:2, and so on? > > That is the role of the XDP program that redirect into a cpumap, and > the key in the cpumap is the CPU number. You mean I have to master this tutorial: https://github.com/xdp-project/xdp-tutorial/blob/master/setup_dependencies.org right? > > > > 3) Is XDP available in kernel 5.4.0 ? > > I think so. > > The real question is what NIC card drivers are you using? driver=i40e driverversion=2.8.20-k duplex=full firmware=8.15 Is it ok for xdp use? > > > > 4) Is XPS a suitable "substitute" for XDP ? > > XPS and XDP are completely unrelated kernel features. I thought their both primary goal was to redirect packets to be handled by a specific CPU. The difference would be that XDP does this upstream compared with XPS. At least, I understand this way reading https://developers.redhat.com/blog/2021/05/13/receive-side-scaling-rss-with-ebpf-and-cpumap# at "Faster software receive steering with XDP" paragraph Is my understanding incorrect? Regards Ethy > > -- > Best regards, > Jesper Dangaard Brouer > MSc.CS, Principal Kernel Engineer at Red Hat > LinkedIn: http://www.linkedin.com/in/brouer > -- Ethy H. Brito /"\ InterNexo Ltda. \ / CAMPANHA DA FITA ASCII - CONTRA MAIL HTML +55 (12) 3797-6860 X ASCII RIBBON CAMPAIGN - AGAINST HTML MAIL S.J.Campos - Brasil / \ PGP key: http://www.inexo.com.br/~ethy/0xC3F222A0.asc
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