Re: Poor performance with stable/13 and Mellanox ConnectX-6 (mlx5)

From: Alexander V. Chernikov <melifaro_at_ipfw.ru>
Date: Thu, 16 Jun 2022 21:00:25 UTC

> On 16 Jun 2022, at 21:48, Mike Jakubik <mike.jakubik@swiftsmsgateway.com> wrote:
> 
> After multiple tests and tweaks i believe the issue is not with the HW or Numa related (Infinity fabric should do around 32GB) but rather with FreeBSD TCP/IP stack. It's like it cant figure itself out properly for the speed that the HW can do, i keep getting widely varying results when testing. Below is an example of two tests, with about a 15 second break in between the two.
Does pinning iperf to a specific CPU core (or range) address the variety part? e.g. cpuset -l 1 perf …
The output you shared above shows CPU#83 as the core iperf is running on. Just wondering whether the scheduler migrates iperf too often, thrashing the caches.

> 
> [root@db-02 ~]# iperf3 -i 1 -t 30 -c db-01 
> Connecting to host db-01, port 5201
> [  5] local 192.168.10.31 port 49155 connected to 192.168.10.30 port 5201
> [ ID] Interval           Transfer     Bitrate         Retr  Cwnd
> [  5]   0.00-1.00   sec   991 MBytes  8.32 Gbits/sec  268    579 KBytes
> [  5]   1.00-2.00   sec   945 MBytes  7.93 Gbits/sec  369    777 KBytes
> [  5]   2.00-3.00   sec   793 MBytes  6.65 Gbits/sec   60   1.03 MBytes
> [  5]   3.00-4.00   sec   666 MBytes  5.59 Gbits/sec  203    976 KBytes
> [  5]   4.00-5.01   sec   575 MBytes  4.78 Gbits/sec  202   1.13 MBytes
> [  5]   5.01-6.00   sec   169 MBytes  1.43 Gbits/sec  134    699 KBytes
> [  5]   6.00-7.00   sec  1.21 GBytes  10.4 Gbits/sec  383   1.08 MBytes
> [  5]   7.00-8.00   sec  1.21 GBytes  10.4 Gbits/sec    0   1.16 MBytes
> [  5]   8.00-9.00   sec  1.32 GBytes  11.3 Gbits/sec  124    780 KBytes
> [  5]   9.00-10.00  sec   690 MBytes  5.79 Gbits/sec  316    605 KBytes
> [  5]  10.00-11.00  sec   685 MBytes  5.75 Gbits/sec   97    854 KBytes
> [  5]  11.00-12.00  sec  1.08 GBytes  9.30 Gbits/sec  383    538 KBytes
> [  5]  12.00-13.00  sec   682 MBytes  5.72 Gbits/sec   88    870 KBytes
> [  5]  13.00-14.00  sec   678 MBytes  5.69 Gbits/sec  123    964 KBytes
> [  5]  14.00-15.00  sec   670 MBytes  5.62 Gbits/sec  290    763 KBytes
> [  5]  15.00-16.00  sec  1.01 GBytes  8.71 Gbits/sec  228   1.08 MBytes
> [  5]  16.00-17.00  sec   886 MBytes  7.44 Gbits/sec  118    615 KBytes
> [  5]  17.00-18.00  sec   734 MBytes  6.16 Gbits/sec  291    902 KBytes
> [  5]  18.00-19.00  sec  1.04 GBytes  8.96 Gbits/sec  212    323 KBytes
> [  5]  19.00-20.00  sec   710 MBytes  5.96 Gbits/sec  193    547 KBytes
> [  5]  20.00-21.00  sec   693 MBytes  5.82 Gbits/sec  370    942 KBytes
> [  5]  21.00-22.00  sec   704 MBytes  5.91 Gbits/sec   80   1022 KBytes
> [  5]  22.00-23.00  sec  1.26 GBytes  10.8 Gbits/sec  262    965 KBytes
> [  5]  23.00-24.00  sec   828 MBytes  6.94 Gbits/sec  202    763 KBytes
> [  5]  24.00-25.00  sec   774 MBytes  6.49 Gbits/sec  227    581 KBytes
> [  5]  25.00-26.00  sec   734 MBytes  6.15 Gbits/sec  256    664 KBytes
> [  5]  26.00-27.00  sec   753 MBytes  6.32 Gbits/sec  331    540 KBytes
> [  5]  27.00-28.00  sec   764 MBytes  6.41 Gbits/sec  298    823 KBytes
> [  5]  28.00-29.00  sec   757 MBytes  6.35 Gbits/sec  123    850 KBytes
> [  5]  29.00-30.00  sec   754 MBytes  6.32 Gbits/sec   74    970 KBytes
> - - - - - - - - - - - - - - - - - - - - - - - - -
> [ ID] Interval           Transfer     Bitrate         Retr
> [  5]   0.00-30.00  sec  24.4 GBytes  6.98 Gbits/sec  6305             sender
> [  5]   0.00-30.00  sec  24.4 GBytes  6.98 Gbits/sec                  receiver
> 
> iperf Done.
> 
> [root@db-02 ~]# iperf3 -i 1 -t 30 -c db-01
> Connecting to host db-01, port 5201
> [  5] local 192.168.10.31 port 25061 connected to 192.168.10.30 port 5201
> [ ID] Interval           Transfer     Bitrate         Retr  Cwnd
> [  5]   0.00-1.00   sec  1.81 GBytes  15.5 Gbits/sec    0   1.11 MBytes
> [  5]   1.00-2.00   sec  1.83 GBytes  15.7 Gbits/sec    0   1.11 MBytes
> [  5]   2.00-3.00   sec  1.98 GBytes  17.0 Gbits/sec    0   1.11 MBytes
> [  5]   3.00-4.00   sec  2.11 GBytes  18.1 Gbits/sec    0   1.11 MBytes
> [  5]   4.00-5.00   sec  2.12 GBytes  18.2 Gbits/sec    0   1.11 MBytes
> [  5]   5.00-6.00   sec  2.16 GBytes  18.5 Gbits/sec    0   1.11 MBytes
> [  5]   6.00-7.00   sec  1.90 GBytes  16.3 Gbits/sec    0   1.12 MBytes
> [  5]   7.00-8.02   sec  1.28 GBytes  10.8 Gbits/sec    0   1.12 MBytes
> [  5]   8.02-9.00   sec  1.83 GBytes  16.0 Gbits/sec    0   1.17 MBytes
> [  5]   9.00-10.00  sec  1.91 GBytes  16.4 Gbits/sec    0   1.20 MBytes
> [  5]  10.00-11.00  sec  1.79 GBytes  15.3 Gbits/sec    0   1.60 MBytes
> [  5]  11.00-12.00  sec  1.77 GBytes  15.2 Gbits/sec    0   1.60 MBytes
> [  5]  12.00-13.00  sec  1.69 GBytes  14.5 Gbits/sec    0   1.61 MBytes
> [  5]  13.00-14.00  sec  1.57 GBytes  13.5 Gbits/sec    0   1.61 MBytes
> [  5]  14.00-15.00  sec  1.60 GBytes  13.8 Gbits/sec    0   1.61 MBytes
> [  5]  15.00-16.00  sec  1.89 GBytes  16.2 Gbits/sec    0   1.61 MBytes
> [  5]  16.00-17.00  sec  1.76 GBytes  15.1 Gbits/sec    0   1.61 MBytes
> [  5]  17.00-18.00  sec  1.93 GBytes  16.6 Gbits/sec    0   1.61 MBytes
> [  5]  18.00-19.00  sec  1.77 GBytes  15.2 Gbits/sec    0   1.61 MBytes
> [  5]  19.00-20.00  sec  1.68 GBytes  14.5 Gbits/sec    0   1.61 MBytes
> [  5]  20.00-21.00  sec  1.66 GBytes  14.3 Gbits/sec    0   1.61 MBytes
> [  5]  21.00-22.00  sec  1.75 GBytes  15.1 Gbits/sec    0   1.61 MBytes
> [  5]  22.00-23.00  sec  1.76 GBytes  15.1 Gbits/sec    0   1.61 MBytes
> [  5]  23.00-24.00  sec  2.05 GBytes  17.7 Gbits/sec    0   1.61 MBytes
> [  5]  24.00-25.00  sec  1.79 GBytes  15.4 Gbits/sec    0   1.61 MBytes
> [  5]  25.00-26.00  sec  1.71 GBytes  14.7 Gbits/sec    0   1.61 MBytes
> [  5]  26.00-27.00  sec  2.08 GBytes  17.9 Gbits/sec    0   1.61 MBytes
> [  5]  27.00-28.00  sec  2.09 GBytes  18.0 Gbits/sec    0   1.61 MBytes
> [  5]  28.00-29.00  sec  2.05 GBytes  17.6 Gbits/sec    0   1.61 MBytes
> [  5]  29.00-30.00  sec  1.81 GBytes  15.6 Gbits/sec    0   1.61 MBytes
> - - - - - - - - - - - - - - - - - - - - - - - - -
> [ ID] Interval           Transfer     Bitrate         Retr
> [  5]   0.00-30.00  sec  55.2 GBytes  15.8 Gbits/sec    0             sender
> [  5]   0.00-30.00  sec  55.2 GBytes  15.8 Gbits/sec                  receiver
> 
> iperf Done.
>