Use pin_memory in forward_batch.init_new to reduce decoding latency#21360
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litmei wants to merge 13 commits intosgl-project:mainfrom
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Use pin_memory in forward_batch.init_new to reduce decoding latency#21360litmei wants to merge 13 commits intosgl-project:mainfrom
litmei wants to merge 13 commits intosgl-project:mainfrom
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litmei
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litmei
commented
Apr 7, 2026
litmei
commented
Apr 7, 2026
Comment on lines
+815
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+827
| if _pin: | ||
| mrope_positions_cat = torch.cat( | ||
| [pos for pos in mrope_positions_list], | ||
| dim=1, | ||
| ).pin_memory() | ||
| else: | ||
| mrope_positions_cat = torch.cat( | ||
| [pos for pos in mrope_positions_list], | ||
| dim=1, | ||
| ) | ||
| self.mrope_positions = mrope_positions_cat.to( | ||
| dtype=torch.int64, device=model_runner.device | ||
| ) |
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could this part be simpler?
litmei
commented
Apr 8, 2026
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Motivation
In low-latency scenarios, there are substantial idle gaps between Decode phases.
Modifications
Profiling analysis identified a Host-to-Device (H2D) synchronization bottleneck within forward_batch.init_new. Applying .pin_memory() converts this synchronous operation into an asynchronous one.
Accuracy Tests
Benchmarking and Profiling
Before:
After:
Checklist
Review Process
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