[ROCm] Limit number of values per thread for reductions on three dimensions #2460
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Jenkins build for 53fbf7866d00ae012510c041cb5c3e13d3a1c214 commit finished as FAILURE |
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reproducer details at pytorch#159652 (comment) |
pruthvistony
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Aug 6, 2025
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! cherry-pick --onto release/2.8 |
okakarpa
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Aug 6, 2025
…nsions (#2460) In the current implementation of reductions in three dimensions for AMD GPUs the number of values per thread is unbounded and can end up being in the hundreds of thousands for certain tensors. This of course is bad for performance. This patch fixes this issue by increasing the parallelism and thus lowering the number of value per thread to reasonable limits i.e. less than 2048 values per thread. The performance gains can be between 10x-17x for certain examples where the number of values per thread was originally very high. cherry-pick of pytorch#159652
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Created branch autogenerated/release/2.8_cherry-pick_pr-2460 and #2469 |
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In the current implementation of reductions in three dimensions for AMD GPUs the number of values per thread is unbounded and can end up being in the hundreds of thousands for certain tensors. This of course is bad for performance. This patch fixes this issue by increasing the parallelism and thus lowering the number of value per thread to reasonable limits i.e. less than 2048 values per thread. The performance gains can be between 10x-17x for certain examples where the number of values per thread was originally very high.
cherry-pick of pytorch#159652
Cherry-picked to release/2.8 branch via #2469