It just goes to show how hard scheduling actually is.
But also, you call it a 'massive' problem and its actually somewhat small in comparison to what can happen with vastly different core types in the same machine. Many of those cores also have quite large cache differences too.
I don't think (but could be wrong) that C++ has a platform independent way of doing this either. I'm not even sure if such an API is exposed from the Windows or linux kernel (though I'd imagine it is).
That to me is the bigger issue here. I can specify which core a thread should run on, but I can't specify what type of core it should run on.
> On platforms with heterogeneous processors, the QoS of a thread may restrict scheduling to a subset of processors, or indicate a preference for a particular class of processor.
https://learn.microsoft.com/en-us/windows/win32/procthread/q...
For starters: https://man7.org/linux/man-pages/man3/pthread_setschedparam....
None of the standard attributes (AFAIK) are directly "put me on a tiny core", but they frequently work hand in hand with those decisions. Lower your priority and the scheduler dumps you on some low clocked small core kinds of effects when its not busy. Or if you have machine knowledge just set your core affinity with pthread_setaffinity_np() which as the extension states is non-portable but can directly translate to "run me on a tiny core" if the right mask is provided.
At least in C/C++ most if not all modern platforms provide these kinds of controls and metadata and while the API might change a bit writing a couple versions of schedule_me_on_a_tiny_core() for each target platform is fairly trivial.