Re: Debian-13 bad performance on IPC

Le 06/07/2026 à 18:56, Ralf Fassel a écrit :

> I installed the rt-kernel, but that made no difference at all.

As Franco Martelli asked: are you sure you booted the real-time kernel 
and not the regular one?

Installation of linux-image-rt-amd64 (real-time kernel) package does not 
remove linux-image-amd64 package (regular kernel).
So after that installation, you have two kernels side-by-side, the 
regular one being the default for boot.

Then if you did not remove or purge (apt remove or apt purge followed by 
the desired package name), or did not specifically chose the real-time 
kernel in the grub menu, chances are that you booted the regular one, 
hence the same results.

> As I understand it, I would need to recompile my programs to actually
> request the realtime features - which I did not do.
[...]
I am really far from knowing much on the subject, but are you not 
confusing real-time operating and multithreading?

I would think that real-time on Linux is done by booting a real-time 
Linux image,

  while multithreading (on Linux, I don't know if Windows has some sorts 
of magic tricks) is done either explicitly by writing programs with 
detailed multithreading instructions, or implicitly writing generic 
global instructions for implicit multithreading.
And only then you have to recompile your code (if it's your code, 
because nowadays I suppose a data acquisition program, either commercial 
or communautary one, is systematically multithread).

Please don't take my word on all this without verifying by asking to 
more competent people.