From: Alexander Bluhm <bluhm@openbsd.org>
Subject: Re: UDP parallel input
To: Andrew Lemin <andrew.lemin@gmail.com>
Cc: tech@openbsd.org
Date: Fri, 26 Jul 2024 13:17:41 +0200

On Fri, Jul 26, 2024 at 05:25:13PM +1000, Andrew Lemin wrote:
> Just to clarify, you mention "you need multiple CPUs and network interfaces
> that support multiqueue".
> Mellanox cards have multiple queues;
> https://github.com/openbsd/src/blob/master/sys/dev/pci/if_mcx.c

Driver looks like mcx(4) supports it.  But I am conservative in my
statements.  Other drivers write the number of queues in dmesg.

bnxt0 at pci4 dev 0 function 0 "Broadcom BCM57412" rev 0x01: fw ver 214.4.91, msix, 8 queues, address 14:23:f2:a0:71:e0
igc0 at pci11 dev 0 function 0 "Intel I225-LM" rev 0x03, msix, 4 queues, address 24:5e:be:54:8a:41
ix0 at pci6 dev 0 function 0 "Intel 82599" rev 0x01, msix, 8 queues, address 90:e2:ba:d6:23:68
ixl0 at pci5 dev 0 function 0 "Intel X710 SFP+" rev 0x02: port 0, FW 6.0.48442 API 1.7, msix, 8 queues, address 40:a6:b7:6e:ad:a0
vmx0 at pci11 dev 0 function 0 "VMware VMXNET3" rev 0x01: msix, 4 queues, address 00:0c:29:2e:8e:8b

But mcx does not.

mcx0 at pci1 dev 0 function 0 "Mellanox ConnectX-4 Lx" rev 0x00: FW 14.23.1020, msix, address b8:59:9f:0e:57:54

Unfortunately all my mcx card are in ARM machines, I don't have
them plugged in my Intel setup.  So I don't know if multiqueue does
work on mcx on arm64, or if they are just missing the print.

Did you test UDP parallel input on mcx(4)?  Does it work?  Do you
see performance improvements?

Maybe we could add a queues print for consistency.  Maybe I can
rearrange my hardware setup to do performance tests also for mcx.

bluhm