forked from OSchip/llvm-project
c5348aecd7
Summary: Retaining per device primary context is preferred to creating a context owned by the plugin. From CUDA documentation 1. Note that the use of multiple CUcontext s per device within a single process will substantially degrade performance and is strongly discouraged. Instead, it is highly recommended that the implicit one-to-one device-to-context mapping for the process provided by the CUDA Runtime API be used." from https://docs.nvidia.com/cuda/cuda-runtime-api/group__CUDART__DRIVER.html 2. Right under cuCtxCreate. In most cases it is recommended to use cuDevicePrimaryCtxRetain. https://docs.nvidia.com/cuda/cuda-driver-api/group__CUDA__CTX.html#group__CUDA__CTX_1g65dc0012348bc84810e2103a40d8e2cf 3. The primary context is unique per device and shared with the CUDA runtime API. These functions allow integration with other libraries using CUDA. https://docs.nvidia.com/cuda/cuda-driver-api/group__CUDA__PRIMARY__CTX.html#group__CUDA__PRIMARY__CTX Two issues are addressed by this patch: 1. Not using the primary context caused interoperability issue with libraries like cublas, cusolver. CUBLAS_STATUS_EXECUTION_FAILED and cudaErrorInvalidResourceHandle 2. On OLCF summit, "Error returned from cuCtxCreate" and "CUDA error is: invalid device ordinal" Regarding the flags of the primary context. If it is inactive, we set CU_CTX_SCHED_BLOCKING_SYNC. If it is already active, we respect the current flags. Reviewers: grokos, ABataev, jdoerfert, protze.joachim, AndreyChurbanov, Hahnfeld Reviewed By: jdoerfert Subscribers: openmp-commits, yaxunl, guansong, sstefan1, tianshilei1992 Tags: #openmp Differential Revision: https://reviews.llvm.org/D82718 |
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| aarch64 | ||
| common | ||
| cuda | ||
| generic-elf-64bit/src | ||
| ppc64 | ||
| ppc64le | ||
| ve | ||
| x86_64 | ||
| CMakeLists.txt | ||
| exports | ||