Version 21.12.0 (December 31, 2021)

• Realm
  • Performance improvements for multi-dimensional copies, especially
    inter-process transfers
  • Support for loading CUDA driver (if present) at runtime instead of
    link time, allowing same binary to be used on systems with and without
    CUDA-capable GPUs (enabled with -DLegion_CUDA_DYNAMIC_LOAD=ON in
    cmake build)
  • A separate Memory is now created per process for external (system)
    memory instances. This memory has no capacity for creating instances
    and can confuse applications or Legion mappers that assume exactly
    one Memory of kind SYSTEM_MEM exists. Old behavior can be obtained
    with -ll:ext_sysmem 0, but this can fail for configurations that
    register system memory with the network and/or GPUs
  • The MemoryQuery now supports a has_capacity predicate to restrict
    results to just memories with sufficient total (not current!) capacity
    to allocate an instance of a specified size
• Build
  • Cmake allows control of max nodes (-DLegion_MAX_NUM_NODES=...) and
    max processors/node (-DLegion_MAX_NUM_PROCS=...) supported by
    Legion build
  • Added dependency tracking to make-based builds