Hi Vinicius, On Sat, 12 Oct 2019 at 00:28, Vinicius Costa Gomes <vinicius.go...@intel.com> wrote: > > Hi, > > Murali Karicheri <m-kariche...@ti.com> writes: > > > Hi Vinicius, > > > > On 10/11/2019 04:12 PM, Vinicius Costa Gomes wrote: > >> Hi Murali, > >> > >> Murali Karicheri <m-kariche...@ti.com> writes: > >> > >>> Hi, > >>> > >>> I am testing the taprio (802.1Q Time Aware Shaper) as part of my > >>> pre-work to implement taprio hw offload and test. > >>> > >>> I was able to configure tap prio on my board and looking to do > >>> some traffic test and wondering how to play with the tc command > >>> to direct traffic to a specfic queue. For example I have setup > >>> taprio to create 5 traffic classes as shows below;- > >>> > >>> Now I plan to create iperf streams to pass through different > >>> gates. Now how do I use tc filters to mark the packets to > >>> go through these gates/queues? I heard about skbedit action > >>> in tc filter to change the priority field of SKB to allow > >>> the above mapping to happen. Any example that some one can > >>> point me to? > >> > >> What I have been using for testing these kinds of use cases (like iperf) > >> is to use an iptables rule to set the priority for some kinds of traffic. > >> > >> Something like this: > >> > >> sudo iptables -t mangle -A POSTROUTING -p udp --dport 7788 -j CLASSIFY > >> --set-class 0:3 > > Let me try this. Yes. This is what I was looking for. I was trying > > something like this and I was getting an error > > > > tc filter add dev eth0 parent 100: protocol ip prio 10 u32 match ip > > dport 10000 0xffff flowid 100:3 > > RTNETLINK answers: Operation not supported > > We have an error talking to the kernel, -1 > > Hmm, taprio (or mqprio for that matter) doesn't support tc filter > blocks, so this won't work for those qdiscs. > > I never thought about adding support for it, it looks very interesting. > Thanks for pointing this out. I will add this to my todo list, but > anyone should feel free to beat me to it :-) > > > Cheers, > -- > Vinicius
What do you mean taprio doesn't support tc filter blocks? What do you think there is to do in taprio to support that? I don't think Murali is asking for filter offloading, but merely for a way to direct frames to a certain traffic class on xmit from Linux. Something like this works perfectly fine: sudo tc qdisc add dev swp2 root handle 1: taprio num_tc 2 map 0 1 queues 1@0 1@1 base-time 1000 sched-entry S 03 300000 flags 2 # Add the qdisc holding the classifiers sudo tc qdisc add dev swp2 clsact # Steer L2 PTP to TC 1 (see with "tc filter show dev swp2 egress") sudo tc filter add dev swp2 egress prio 1 u32 match u16 0x88f7 0xffff at -2 action skbedit priority 1 However, the clsact qdisc and tc u32 egress filter can be replaced with proper use of the SO_PRIORITY API, which is preferable for new applications IMO. I'm trying to send a demo application to tools/testing/selftests/ which sends cyclic traffic through a raw L2 socket at a configurable base-time and cycle-time, along with the accompanying scripts to set up the receiver and bandwidth reservation on an in-between switch. But I have some trouble getting the sender application to work reliably at 100 us cycle-time, so it may take a while until I figure out with kernelshark what's going on. Regards, -Vladimir
