Bitmaps for logical CPU cores and certain lock-free algorithms don't scale well to arbitrary high CPU counts e.g. reclaiming resources once in a while is O(n^2)

Bitmaps for logical CPU cores and certain lock-free algorithms don't scale well to arbitrary high CPU counts e.g. reclaiming resources once in a while is O(n^2) or worse or the size of the lock structure is linear to the maximum number of cores etc. The relevant parts of the ABI have been future proofed to allow raising the kernel CPU core count limit without breaking the syscall interface for systems with less cores than the existing limit.