[PyTorch Pinned Allocator] Add support of reserved pinned memory segment to avoid slow paths#164501
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[PyTorch Pinned Allocator] Add support of reserved pinned memory segment to avoid slow paths#164501banitag1 wants to merge 1 commit intopytorch:mainfrom
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…ent to avoid slow paths Summary: This diff adds the feature of allocating a large pinned memory segment upfront based on the provided config. This large segment is then used to serve all the small pinned memory requests to avoid expensive device level APIs (slow paths). Example: PYTORCH_CUDA_ALLOC_CONF=pinned_reserve_segment_size_mb:2048 This reserves a 2GB pinned memory segment for the process and then all incoming small requests are just served from this segment and no cudaHostAlloc/cudaHostRegister apis are being called. Differential Revision: D83779074
🔗 Helpful Links🧪 See artifacts and rendered test results at hud.pytorch.org/pr/164501
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yangw-dev
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Oct 2, 2025
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@pytorchbot label "release notes: cuda" |
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@pytorchbot merge (Initiating merge automatically since Phabricator Diff has merged) |
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Merge startedYour change will be merged once all checks pass (ETA 0-4 Hours). Learn more about merging in the wiki. Questions? Feedback? Please reach out to the PyTorch DevX Team |
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Merge failedReason: 1 jobs have failed, first few of them are: trunk / macos-py3-arm64 / build Details for Dev Infra teamRaised by workflow job |
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@pytorchbot merge |
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Merge startedYour change will be merged once all checks pass (ETA 0-4 Hours). Learn more about merging in the wiki. Questions? Feedback? Please reach out to the PyTorch DevX Team |
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Oct 21, 2025
…ent to avoid slow paths (pytorch#164501) Summary: This diff adds the feature of allocating a large pinned memory segment upfront based on the provided config. This large segment is then used to serve all the small pinned memory requests to avoid expensive device level APIs (slow paths). Example: PYTORCH_CUDA_ALLOC_CONF=pinned_reserve_segment_size_mb:2048 This reserves a 2GB pinned memory segment for the process and then all incoming small requests are just served from this segment and no cudaHostAlloc/cudaHostRegister apis are being called. Differential Revision: D83779074 Pull Request resolved: pytorch#164501 Approved by: https://github.com/yangw-dev
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Summary:
This diff adds the feature of allocating a large pinned memory segment upfront based on the provided config. This large segment is then used to serve all the small pinned memory requests to avoid expensive device level APIs (slow paths).
Example:
PYTORCH_CUDA_ALLOC_CONF=pinned_reserve_segment_size_mb:2048
This reserves a 2GB pinned memory segment for the process and then all incoming small requests are just served from this segment and no cudaHostAlloc/cudaHostRegister apis are being called.
Differential Revision: D83779074