diff --git a/src/flamegpu/simulation/CUDAEnsemble.cu b/src/flamegpu/simulation/CUDAEnsemble.cu index 42c7a31a1..ae6074a80 100644 --- a/src/flamegpu/simulation/CUDAEnsemble.cu +++ b/src/flamegpu/simulation/CUDAEnsemble.cu @@ -63,9 +63,7 @@ unsigned int CUDAEnsemble::simulate(const RunPlanVector& plans) { } #ifdef FLAMEGPU_ENABLE_MPI - std::unique_ptr mpi = config.mpi - ? std::make_unique(config, static_cast(plans.size())) - : nullptr; + std::unique_ptr mpi = std::make_unique(config, static_cast(plans.size())); #endif // Validate/init output directories @@ -165,10 +163,8 @@ unsigned int CUDAEnsemble::simulate(const RunPlanVector& plans) { } } #ifdef FLAMEGPU_ENABLE_MPI - // if MPI is enabled at compile time, and mpi is enabled in the config, use the MPIEnsemble method to assign devices balanced across ranks - if (mpi != nullptr) { - devices = mpi->devicesForThisRank(devices); - } + // if MPI is enabled at compile time, use the MPIEnsemble method to assign devices balanced across ranks + devices = mpi->devicesForThisRank(devices); #endif // ifdef FLAMEGPU_ENABLE_MPI // Check that each device is capable, and init cuda context @@ -186,32 +182,26 @@ unsigned int CUDAEnsemble::simulate(const RunPlanVector& plans) { gpuErrchk(cudaSetDevice(0)); // If there are no devices left (and mpi is not being used), we need to error as the work cannot be executed. -#ifdef FLAMEGPU_ENABLE_MPI - if (devices.size() == 0 && mpi == nullptr) { - THROW exception::InvalidCUDAdevice("FLAMEGPU2 has not been built with an appropraite compute capability for any devices, unable to continue\n"); - } -#else // FLAMEGPU_ENABLE_MPI +#ifndef FLAMEGPU_ENABLE_MPI if (devices.size() == 0) { THROW exception::InvalidCUDAdevice("FLAMEGPU2 has not been built with an appropraite compute capability for any devices, unable to continue\n"); } -#endif // FLAMEGPU_ENABLE_MPI +#endif // ifndef FLAMEGPU_ENABLE_MPI #ifdef FLAMEGPU_ENABLE_MPI // Once the number of devices per rank is known, we can create the actual communicator to be used during MPI, so we can warn/error as needed. - if (mpi != nullptr) { - // This rank is participating if it has atleast one device assigned to it. - // Rank 0 will be participating at this point, otherwise InvalidCUDAdevice would have been thrown - // This also implies the participating communicator cannot have a size of 0, as atleast one thread must be participating at this point, but throw in that case just in case. - bool communicatorCreated = mpi->createParticipatingCommunicator(devices.size() > 0); - // If the communicator failed to be created or is empty for any participating threads, throw. This should never occur. - if (!communicatorCreated || mpi->getParticipatingCommSize() == 0) { - THROW exception::EnsembleError("Unable to create MPI communicator. Ensure atleast one GPU is visible.\n"); - } - // If the world size is not the participating size, issue a warning.that too many threads have been used. - if (mpi->world_rank == 0 && mpi->world_size != mpi->getParticipatingCommSize() && config.verbosity >= Verbosity::Default) { - fprintf(stderr, "Warning: MPI Ensemble launched with %d MPI ranks, but only %d ranks have GPUs assigned. %d ranks are unneccesary.\n", mpi->world_size, mpi->getParticipatingCommSize(), mpi->world_size - mpi->getParticipatingCommSize()); - fflush(stderr); - } + // This rank is participating if it has atleast one device assigned to it. + // Rank 0 will be participating at this point, otherwise InvalidCUDAdevice would have been thrown + // This also implies the participating communicator cannot have a size of 0, as atleast one thread must be participating at this point, but throw in that case just in case. + bool communicatorCreated = mpi->createParticipatingCommunicator(devices.size() > 0); + // If the communicator failed to be created or is empty for any participating threads, throw. This should never occur. + if (!communicatorCreated || mpi->getParticipatingCommSize() == 0) { + THROW exception::EnsembleError("Unable to create MPI communicator. Ensure atleast one GPU is visible.\n"); + } + // If the world size is not the participating size, issue a warning.that too many threads have been used. + if (mpi->world_rank == 0 && mpi->world_size != mpi->getParticipatingCommSize() && config.verbosity >= Verbosity::Default) { + fprintf(stderr, "Warning: MPI Ensemble launched with %d MPI ranks, but only %d ranks have GPUs assigned. %d ranks are unneccesary.\n", mpi->world_size, mpi->getParticipatingCommSize(), mpi->world_size - mpi->getParticipatingCommSize()); + fflush(stderr); } #endif