Ipq40xx and DSA, current status?

Installing and Using OpenWrt
1

I've got remote ipq40xx device, running OpenWRT 22.03, routing/NAT'ing gigabit fiber at line speed (software offload + steering + irqbalance) with sub 50% load evenly distributed across all four CPU cores.

All happy, no complaints, no regrets... other than 22.03 getting EOL and out of support in a few months.

Now 23.05 has migrated from swconfig to DSA and I see several forum threads with complaints about severe performance regressions.

So my question is blunt, what is a current state of ipq40xx in 23.05 or master, routing performance wise?

Any point driving to remote location to upgrade ipq40xx router, can I expect it to handle gigabit fiber, as it does now?

2

DSA for ipq40xx should be fine in 23.05.x and above.

1 GBit/s wirespeed however is unlikely, regardless of DSA or not. In my own (synthetic) benchmarking with swconfig (as DSA support didn't exist back when I tested that), showed it to max out around 300 MBit/s (software flow-offloading will obviously extend that, but that wasn't the focus of my testing).

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3

@notgood to sum up:

Before DSA you could reach about 600 Mbps. (after doing some tweaks like irqbalance, changing cpu to performance mode....).

After DSA you could reach about 200 Mbps.

4

I disagree, in fact tested just now:

  1. IPQ4018 router (ZyXEL NBG6617) running rather fresh OpenWRT 22.03 build, irqbalance and packet steering on.
  2. Iperf3 client running on other host in LAN, iperf3 server on VPS elsewhere.

Software offloading ON, router CPU load at like 25% all cores, bottlenecked by line speed.

[SUM]   0.00-20.01  sec  2.19 GBytes   940 Mbits/sec   88             sender
[SUM]   0.00-20.00  sec  2.18 GBytes   934 Mbits/sec                  receiver

Software offloading OFF, router CPU 100% on first core, bottlenecked by CPU.

[SUM]   0.00-20.01  sec  1.51 GBytes   647 Mbits/sec  1787             sender
[SUM]   0.00-20.00  sec  1.50 GBytes   644 Mbits/sec                  receiver
5

Yup, confirming 600+ Mbit/s without offload on 22.03

That would be a deal breaker to me, why merge such disruptive changes...

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6

I have a MR8300 router (ipq40xx) running 22.03 with no plan to software upgrade until performance issue will be resolved.

7

Only you can check if there indeed are performance drops. My experience is that the stated throughputs are beyond ipq40xx's limits, swconfig or not, but I have not tested with software flow-offloading (as it doesn't meet my requirements) and I do err on the pessimistic side (margins).

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