pytorch/torch/utils/data
xangma fe8d66d9a6 Faster Faster BatchSampler (#137423)
Builds upon #76951.

Benchmarking code is the same as in #76950.

AMD Ryzen Threadripper PRO 3995WX:
```
  batch_size  drop_last      origin     new  speedup
------------  -----------  --------  ------  ---------
           4  True           0.94    0.5706  64.74%
           4  False          0.9745  0.9468  2.93%
           8  True           0.7423  0.3715  99.82%
           8  False          0.7974  0.5666  40.73%
          64  True           0.5394  0.2085  158.76%
          64  False          0.6083  0.2697  125.51%
         640  True           0.5448  0.1985  174.41%
         640  False          0.7085  0.2308  206.91%
        6400  True           0.5554  0.2028  173.88%
        6400  False          0.7711  0.2109  265.60%
       64000  True           0.556   0.2091  165.82%
       64000  False          0.7803  0.2078  275.58%
```

When `drop_last == True`, it uses `zip` to speed things up.
When `drop_last == False`, it uses `itertools` to speed things up.

`itertools` was the fastest way I could find that deals with the last batch if it is smaller than `batch_size`. I have a pure python method too, but it is slower when `batch_size` is 4 or 8, so I have committed the `itertools` version for now.

Happy to chat further about this change :-) I understand you may not want to introduce the `itertools` package into [sampler.py](https://github.com/pytorch/pytorch/blob/main/torch/utils/data/sampler.py).
Pull Request resolved: https://github.com/pytorch/pytorch/pull/137423
Approved by: https://github.com/Skylion007
2024-10-13 09:36:03 +00:00
..
_utils Add None return type to init (#132335) 2024-08-01 15:26:45 +00:00
datapipes [BE][Easy] enable ruff rule PIE790: unnecessary pass statement (#133200) 2024-08-15 15:50:19 +00:00
__init__.py
backward_compatibility.py
dataframes_pipes.ipynb
dataloader.py
dataset.py
distributed.py
graph_settings.py
graph.py
sampler.py Faster Faster BatchSampler (#137423) 2024-10-13 09:36:03 +00:00
standard_pipes.ipynb
typing.ipynb