Re: Request for Testing: TCP RACK

On Thu, 16 Nov 2023 13:06:03 +0100, "Herbert J. Skuhra" wrote:
> 
> Hi,
> 
> On Thu, 16 Nov 2023 10:13:05 +0100, tuexen@freebsd.org wrote:
> > 
> > Dear all,
> > 
> > recently the main branch was changed to build the TCP RACK stack
> > which is a loadable kernel module, by default:
> > https://cgit.FreeBSD.org/src/commit/?id=3a338c534154164504005beb00a3c6feb03756cc
> > 
> > As discussed on the bi-weekly transport call, it would be great if people
> > could test the RACK stack for their workload. Please report any problems to the
> > net@ mailing list or open an issue in the bug tracker and drop me a note via email.
> > This includes regressions in CPU usage, regressions in performance or any other
> > unexpected change you observe.
> > 
> > You can load the kernel module using
> > kldload tcp_rack
> > 
> > You can make the RACK stack the default stack using
> > sysctl net.inet.tcp.functions_default=rack
> > 
> > Based on the feedback we get, the default stack might be switched to the
> > RACK stack.
> > 
> > Please let me know if you have any questions.
> 
> I am running main-n266450-a592812327de with a GENERIC-NODEBUG kernel.
> 
> # kldload tcp_rack
> kldload: an error occurred while loading module tcp_rack. Please check
> dmesg(8) for more details.
> 
> In dmesg:
> KLD tcp_rack.ko: depends on tcphpts - not available or version mismatch
> linker_load_file: /boot/kernel/tcp_rack.ko - unsupported file type
> 
> So you have to build a kernel with "options TCPHPTS" first?

OK, I am now running GENERIC-NODEBUG + "options TCPHPTS".

After setting "sysctl net.inet.tcp.functions_default=rack" git no
longer works:

# sysctl net.inet.tcp.functions_default=rack
$ git pull
client_loop: send disconnect: Broken pipe
fatal: the remote end hung up upon initial contact
# sysctl net.inet.tcp.functions_default=freebsd
$ git pull
Already up to date.

--
Herbert