Disallow creation of ProcessGroupNCCL without GPUs. #45642
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Prior to #45181, initializing a NCCL process group would work even if no GPUs were present. Although, now since init_process_group calls `barrier()` this would fail. In general the problem was that we could initialize ProcessGroupNCCL without GPUs and then if we called a method like `barrier()` the process would crash since we do % numGPUs resulting in division by zero. Differential Revision: [D24038839](https://our.internmc.facebook.com/intern/diff/D24038839/) [ghstack-poisoned]
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Prior to #45181, initializing a NCCL process group would work even if no GPUs were present. Although, now since init_process_group calls `barrier()` this would fail. In general the problem was that we could initialize ProcessGroupNCCL without GPUs and then if we called a method like `barrier()` the process would crash since we do % numGPUs resulting in division by zero. Differential Revision: [D24038839](https://our.internmc.facebook.com/intern/diff/D24038839/) ghstack-source-id: 113302257 Pull Request resolved: #45642
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@@ Coverage Diff @@
## gh/pritamdamania87/167/base #45642 +/- ##
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- Coverage 68.66% 68.66% -0.01%
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Files 406 406
Lines 52223 52223
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- Hits 35858 35857 -1
- Misses 16365 16366 +1
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Prior to #45181, initializing a NCCL process group would work even if no GPUs were present. Although, now since init_process_group calls `barrier()` this would fail. In general the problem was that we could initialize ProcessGroupNCCL without GPUs and then if we called a method like `barrier()` the process would crash since we do % numGPUs resulting in division by zero. Differential Revision: [D24038839](https://our.internmc.facebook.com/intern/diff/D24038839/) [ghstack-poisoned]
pritamdamania87
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Pull Request resolved: #45642 Prior to #45181, initializing a NCCL process group would work even if no GPUs were present. Although, now since init_process_group calls `barrier()` this would fail. In general the problem was that we could initialize ProcessGroupNCCL without GPUs and then if we called a method like `barrier()` the process would crash since we do % numGPUs resulting in division by zero. ghstack-source-id: 113490343 Differential Revision: [D24038839](https://our.internmc.facebook.com/intern/diff/D24038839/)
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This pull request has been merged in b5a2f04. |
pritamdamania87
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) Summary: Note: This PR has been merged into master at b5a2f04 after the 1.7 branch cut (see original PR: #45642). This PR is to merge it into the 1.7 branch. ---- Original Commit Description Follows --- Pull Request resolved: #45642 Prior to #45181, initializing a NCCL process group would work even if no GPUs were present. Although, now since init_process_group calls `barrier()` this would fail. In general the problem was that we could initialize ProcessGroupNCCL without GPUs and then if we called a method like `barrier()` the process would crash since we do % numGPUs resulting in division by zero. ghstack-source-id: 113490343 Test Plan: waitforbuildbot Reviewed By: osalpekar Differential Revision: D24038839 fbshipit-source-id: a1f1db52cabcfb83e06c1a11ae9744afbf03f8dc
This was referenced Oct 9, 2020
malfet
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) (#46073) Summary: Note: This PR has been merged into master at b5a2f04 after the 1.7 branch cut (see original PR: #45642). This PR is to merge it into the 1.7 branch. ---- Original Commit Description Follows --- Pull Request resolved: #45642 Prior to #45181, initializing a NCCL process group would work even if no GPUs were present. Although, now since init_process_group calls `barrier()` this would fail. In general the problem was that we could initialize ProcessGroupNCCL without GPUs and then if we called a method like `barrier()` the process would crash since we do % numGPUs resulting in division by zero. ghstack-source-id: 113490343 Test Plan: waitforbuildbot Reviewed By: osalpekar Differential Revision: D24038839 fbshipit-source-id: a1f1db52cabcfb83e06c1a11ae9744afbf03f8dc Co-authored-by: Pritam Damania <[email protected]>
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Stack from ghstack:
Prior to #45181, initializing a
NCCL process group would work even if no GPUs were present. Although, now since
init_process_group calls
barrier()this would fail.In general the problem was that we could initialize ProcessGroupNCCL without
GPUs and then if we called a method like
barrier()the process would crashsince we do % numGPUs resulting in division by zero.
Differential Revision: D24038839