[PATCH v3 0/2] allow creating thread with real-time priority

[Morten Brørup]

> From: Thomas Monjalon [mailto:thomas at monjalon.net]
> Sent: Thursday, 26 October 2023 15.37
> 
> 25/10/2023 18:31, Thomas Monjalon:
> > Real-time thread priority was been forbidden on Unix
> > because of problems they can cause.
> > Warnings and helpers are added to avoid deadlocks,
> > so real-time can be allowed on all systems.
> 
> Unit test is failing:
> DPDK:fast-tests / threads_autotest      TIMEOUT 600.01 s
> 
> It is seen in only 1 target (maybe the failure occurence is random):
>   Debian 11 (Buster) (ARM) | PASS
>   Fedora 37 (ARM)          | PASS
>   CentOS Stream 9 (ARM)    | FAIL
>   Fedora 38 (ARM)          | PASS
>   Fedora 38 (ARM Clang)    | PASS
>   Ubuntu 20.04 (ARM)       | PASS
> 
> I need to send a v4 with new implementation and better comments.
> The Unix sleep will be upgraded from 1 ns to 1 us in case it makes a
> difference.

It will not make a difference. The kernel will go through the sleeping steps, then wake up again and see the real-time thread is ready to run, and then immediately schedule it.

For testing purposes, consider sleeping 10 milliseconds or something significant like that.