• Robert Maynard's avatar
    VTK-m now provides better scheduling parameters controls · 047b6465
    Robert Maynard authored
    VTK-m now offers a more GPU aware set of defaults for kernel scheduling.
    When VTK-m first launches a kernel we do system introspection and determine
    what GPU's are on the machine and than match this information to a preset
    table of values. The implementation is designed in a way that allows for
    VTK-m to offer both specific presets for a given GPU ( V100 ) or for
    an entire generation of cards ( Pascal ).
    Currently VTK-m offers preset tables for the following GPU's:
    - Tesla V100
    - Tesla P100
    If the hardware doesn't match a specific GPU card we than try to find the
    nearest know hardware generation and use those defaults. Currently we offer
    defaults for
    - Older than Pascal Hardware
    - Pascal Hardware
    - Volta+ Hardware
    Some users have workloads that don't align with the defaults provided by
    VTK-m. When that is the cause, it is possible to override the defaults
    by binding a custom function to `vtkm::cont::cuda::InitScheduleParameters`.
    As shown below:
      ScheduleParameters CustomScheduleValues(char const* name,
                                              int major,
                                              int minor,
                                              int multiProcessorCount,
                                              int maxThreadsPerMultiProcessor,
                                              int maxThreadsPerBlock)
        ScheduleParameters params  {
            64 * multiProcessorCount,  //1d blocks
            64,                        //1d threads per block
            64 * multiProcessorCount,  //2d blocks
            { 8, 8, 1 },               //2d threads per block
            64 * multiProcessorCount,  //3d blocks
            { 4, 4, 4 } };             //3d threads per block
        return params;
improve-cuda-scheduling.md 1.83 KB