Re: Request for Testing: TCP RACK

From: <tuexen_at_freebsd.org>
Date: Sun, 17 Mar 2024 09:18:16 UTC
> On 16. Mar 2024, at 21:29, Nuno Teixeira <eduardo@freebsd.org> wrote:
> 
>> Just to double check: you only load the tcp_rack. You don't run
>> sysctl net.inet.tcp.functions_default=rack
> 
> I'm not using sysctl, just loading module.
And you also don't have
net.inet.tcp.functions_default=rack
in /etc/sysctl.conf
This means that no TCP connection will actually use the RACK stack.
> 
>> What does "poudriere testport net/gitup" do? Only build stuff or does is
>> also download something?
>> 
>> What does bonnie++ do?
> 
> poudriere is for testing ports and it uses jails to build stuff.
> It have restrict access to net to fetch distfiles (not the case as
> distfile is present on disk)
> 
> bonnie++ is a disk benchmark
Thanks for clarifying.
> 
>> Could you reboot the system, run the test, do kldload tcphpts, run
>> the test again, do kldload tcp_rack, and run it again.
> 
> The previous test [2] was obtained by loading tcp_rack
> 
> Now I will post results for test [3] by loading (only) tcphpts module.
Great. This makes sure that the degradation is related to TCPHPTS and
not the RACK stack.
> 
> [3] kldload tcphpts:
> 
> ==> poudriere testport net/gitup:
> 55.26s real             5.23s user              1m19.91s sys
So this test goes up from 11 seconds to 55 seconds...
> 
> ==> bonnie++
> Version  1.98       ------Sequential Output------ --Sequential Input- --Random-
>                   -Per Chr- --Block-- -Rewrite- -Per Chr- --Block-- --Seeks--
> Name:Size etc        /sec %CP  /sec %CP  /sec %CP  /sec %CP  /sec %CP  /sec %CP
> leg.home        32G   12k  99 73.0m  99 51.1m  99   27k  99  128m  99  8038 2194
> Latency              1763ms     194ms   23979us     431ms    1267us    2776us
> Version  1.98       ------Sequential Create------ --------Random Create--------
> leg.home            -Create-- --Read--- -Delete-- -Create-- --Read--- -Delete--
>             files  /sec %CP  /sec %CP  /sec %CP  /sec %CP  /sec %CP  /sec %CP
>                16 7017.934752  98 21243.823180 100 7780.918458  99
> 9281.477778  98 21368.647657 100 7457.828733  99
> Latency              3015us     220us    2398us    1106us     386us    2473us
> 
> Summary:
> 
> - I can't remember better tests to do as I can feel the entire OS is
> being slow, without errors, just slow.
This is interesting. It seems a consequence on loading TCPHPTS, not actually
using it.

I have CCed Drew and Randall, who know much more about HPTS and might have
follow up questions. I'll bring the issue up in the FreeBSD transport call
next Thursday.

What hardware are you using?

Best regards
Michael
> - Approx. results as test [2]
> 
> 
> 
> 
> Nuno Teixeira
> FreeBSD Committer (ports)