be less vocal about affinity where it is not relevant
On (at least) BG/Q and (I think) PowerPC generally, mdrun does issue various warnings about affinity setting that are useless because threads cannot migrate. We should be more sensitive about that. Am I right about PowerPC? x86 and ARM can migrate.
Avoid warning about affinity on Blue Gene, reduce warnings
- Blue Gene does not migrate threads, so don't warn about
affinity setting not being available.
- To avoid flooding users with warnings, just use warnings
when it is very likely the user did something incorrect
when setting pinning options, but notes when it might be
a property of the platform, or when it is not severe.
#2 Updated by Erik Lindahl over 4 years ago
Another alternative is to just warn on platforms where we know it can happen.
I think it is starting to become a problem that a non-expert trying to compile Gromacs can be faced with lots of warnings both when configuring, preparing, and using Gromacs. While the intention of improving performance is admirable, a novice user will rather come away with the impression that Gromacs is difficult to use and that you need to read up on lots of things - and then they are still likely to ignore most warnings since they don't know how to fix them.
In particular, we should limit warnings to things where the scientific integrity of the output is at risk. Mere performance considerations should be a note (just as we do when telling the user we could use a better SIMD instruction set on this hist).