Support async mode for shm allreduce #484
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@d4l3k Could you help review this? |
d4l3k
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Feb 6, 2026
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| std::shared_ptr<AllreduceSharedMemoryData> shmData; | ||
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| std::mutex shmDataMutex; |
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What happens if there's multiple gloo process groups? Does that cause issues at all?
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also can we put this under shmData?
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- For multiple process groups scenario, I used gloo context's address to generate unique ID for shm name. In that case different group will use different shm buffer to do allreduce op. I've verified with a test with multiple process groups with pytorch and it passed.
- I think we could not put this under shmData. In the first run shmData is not initialized(nullptr), if there are multiple threads reaching this point, we need to ensure the initialization work is done only by one thread here.
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This is to fix CI failure of pytorch in bump PR pytorch/pytorch#172297.
In async mode shmData should be occupied exclusively. We added lock for shmData to make it thread safe and used unique tag to do synchronization among different ranks.