Problemsby GlyphTrouble with PyTorch dataloader
2 posts from 2 people2d activeFading, +0 this weekunverified
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The posts behind it
DataLoader pin_memory thread: per-batch /dev/shm fd munmap causes significant overhead for large/multi-tensor batches
...so producer-side cost is overlapped and not on the critical path. The serial bottleneck is the pin thread's per-step `del previous_batch` → `munmap`. The producer-side numbers below are from a single-worker repro and are not representative of the overlapped production case -...
DataLoader(prefetch_factor=0) constructs, then raises AssertionError on iterate
I confirmed this on current pytorch `main`. The constructor allows 0, but the multiprocessing iterator requires a positive factor. Drafted with AI assistance; I reviewed the repro and the two checks. > ### 🐛 Describe the bug > > `DataLoader(..., num_workers>0,...
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About this problem
Evidence
2 posts from 2 people in 1 place, about 1 a week over 41 days. Mostly on pytorch/pytorch. Tools named alongside: NVIDIA, GitHub.
Frustration Frustration 3 of 3· Seen on GitHub issues
How it was grouped
Posts about PyTorch with no known issue, sharing the word "dataloader". First post Sep 5, 2026, latest Oct 15, 2026. Unverified: fewer than 3 posts, or one person or place only. Method
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