OpenMP CMakeLists.txt patch

[Markus Meier]

Hello

would it be possible to include a fix to explicitly disable OpenMP if
requested by the user? The default would still remain the same...
Attached you'll find a proposed patch.

reference:
https://bugs.gentoo.org/show_bug.cgi?id=926788


Thanks in advance!
BR,
Markus

[T. Modes]

Markus Meier schrieb am Sonntag, 24. März 2024 um 10:02:49 UTC+1:

would it be possible to include a fix to explicitly disable OpenMP if
requested by the user?

Sorry, but I don't understand what's your problem here.

This code is in place since 10 years without problems.

Second disabling the OpenMP multithreading does slow down many parts of Hugin.

And the linked bug report does not help further.

[Markus Meier]

On Sun, 24 Mar 2024 05:14:28 -0700 (PDT)
"'T. Modes' via hugin and other free panoramic software"

Sorry for the very late response...

The patch tries to "solve" the automatic linking / usage of the openmp
library in case it's installed. It's kind of the idea by Gentoo to
provide flexibility - meaning to be able to explicitly disable openmp
support for hugin (probably this is a bad idea, but ...).
That's the idea behind the patch, to have openmp detection kind of as
it is now, but the possibility to disable it.

Do you think there's a better way to achieve this?


Thanks and best regards,
Markus

[Gunter Königsmann]

Disabling openMP seems like something that is useful when during debugging one wants to know if some malfunction is a threading race condition. But for compiling the application for the end-user disabling openMP sounds strange to me...