feat: unify shared-prefix Megatron execution#739
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This reverts commit 5474538.
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* origin/main: feat: unify shared-prefix Megatron execution (#739) Add DeepSeek V4 Flash support for ART Megatron (#745) Add ART Megatron support for GPT OSS (#744) ci: bound GPU prewarm cleanup ci: prewarm GPU image on all GPU clusters ci: dispatch Caladan GPU image builds Fix Gemma4 MoE Triton flex stage config (#742) fix: split GPU image dependency warmup # Conflicts: # src/art/dev/model.py # src/art/serverless/backend.py
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Summary
Adds support for deeper shared-prefixes and multi-LoRA slots while simplifying the code. Also adds a dev script for validation and some tests.
What changed
pack_shared_prefixes(...)and shared-prefix tree/parser coverage for depth 0 through deeper branchy trees.create_block_mask, including full/partial block metadata rather than onlymask_modbehavior.dev/megatron_review_perf.pyfor Austin-focused block-mask, FlexAttention, and CP planning measurements.Validation
Local on this branch:
uv run --no-sync prek run --all-files: passed.uv run pytest tests/unit/test_shared_prefix_attention_builder.py tests/unit/test_shared_prefix_tree.py tests/unit/test_shared_prefix_packing.py tests/unit/test_shared_prefix_grad_parity.py tests/integration/megatron/lora/test_lora_disk_codecs.py:30 passed, 9 skippedlocally; GPU/Megatron/vLLM portions are skipped on local macOS.4x H200 SkyPilot (
codex-trainer-rank-h200) on this branch:48 passed.17 passed.Qwen/Qwen3.5-35B-A3B-style packed shape, CP=4, 198k packed tokens, 2.448M logical tokens:60.54ms1.865ms136.503ms3.478ms, CP planning12.916msmain, speed was statistically indistinguishable, both about 33k tok/s.