Re: [PATCH] selftests/net: give more time to udpgro bg processes to complete startup

[Paolo Abeni <pabeni@redhat.com>]

On Thu, 2022-11-03 at 20:46 -0700, Jakub Kicinski wrote:
> On Tue,  1 Nov 2022 14:48:08 -0400 Adrien Thierry wrote:
> > In some conditions, background processes in udpgro don't have enough
> > time to set up the sockets. When foreground processes start, this
> > results in the test failing with "./udpgso_bench_tx: sendmsg: Connection
> > refused". For instance, this happens from time to time on a Qualcomm
> > SA8540P SoC running CentOS Stream 9.
> > 
> > To fix this, increase the time given to background processes to
> > complete the startup before foreground processes start.
> > 
> > Signed-off-by: Adrien Thierry <athierry@redhat.com>
> > ---
> > This is a continuation of the hack that's present in those tests. Other
> > ideas are welcome to fix this in a more permanent way.
> 
> Perhaps we can add an option to the Rx side to daemonize itself after
> setting up the socket, that way the bash script will be locked until 
> Rx is ready?

Then it will be less straigh-forward for the running shell waiting for
all the running processes. 

Another option would be replacing the sleep with a loop waiting for 
the rx UDP socket to appear in the procfs or diag interface, alike what
mptcp self-tests (random example;) are doing:

https://elixir.bootlin.com/linux/v6.1-rc3/source/tools/testing/selftests/net/mptcp/mptcp_join.sh#L424

Cheers,

Paolo