Proxmox slow network with multicore

Started by nicwanz, July 24, 2023, 03:42:10 PM

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Hi all, I'm struggling with slow network flow on a proxmox vm...

with single core VM I have this throughput

[ ID] Interval           Transfer     Bitrate         Retr
[  5]   0.00-30.00  sec  2.81 GBytes   806 Mbits/sec  1550             sender
[  5]   0.00-30.01  sec  2.81 GBytes   805 Mbits/sec                  receiver


but when I set same VM with four cores (1 socket 4 core or 4 socket 1 core) it slow down

[ ID] Interval           Transfer     Bitrate         Retr
[  5]   0.00-60.00  sec  3.04 GBytes   435 Mbits/sec  477             sender
[  5]   0.00-60.01  sec  3.03 GBytes   434 Mbits/sec                  receiver



I read a lot of thd and I set following tunable with GUI but no luck

net.isr.bindthreads="1"
net.isr.maxthreads="-1"
hw.pci.honor_msi_blacklist="0"
hw.ibrs_disable = 1
net.inet.rss.enabled = 1
vm.pmap.pti = 0

Here env info

HW - Dell Optiplex with realteck nic
Kernel Version - Linux 5.15.74-1-pve #1 SMP PVE 5.15.74-1
CPU - 6 x Intel(R) Core(TM) i5-9500T CPU @ 2.20GHz (1 Socket)
PVE Manager Version - pve-manager/7.3-3/c3928077

Any other VM in proxmox (linux/windows) works with no problem, only this Freebsds has this problem.
Any ideas how to debug/solve this strange behaviour?