Better encapsulation of test state.
Use the NELEMS macro to compute the size of arrays.
mps_sac_create does not return MPS_RES_PARAM if the pool does not support caches. This won't be discovered until you try to allocate through the cache.
Don't return ResPARAM from mps_arena_vm_growth if desired < minimum: this is a static programming error (not a dynamic condition) so AVER instead.