h100-sglang-diffusion

Original🇺🇸 English
Translated

SSH into host `h100_sglang`, enter Docker container `sglang_bbuf`, work in `/data/bbuf/repos/sglang`, and use the ready H100 remote environment for SGLang **diffusion** development and validation. Use when a task needs diffusion model smoke tests, Triton/CUDA kernel validation, torch.compile diffusion checks, or a safe remote copy for diffusion-specific SGLang changes.

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NPX Install

npx skill4agent add bbuf/sglang-auto-driven-skills h100-sglang-diffusion

Tags

Translated version includes tags in frontmatter

H100 — SGLang Diffusion

Overview

Use this skill to do SGLang diffusion development on the H100 box through
h100_sglang
. The default container is
sglang_bbuf
and the repo lives at
/data/bbuf/repos/sglang
.
Prefer this skill when:
  • Validating diffusion Triton / CUDA JIT kernels
  • Running diffusion model smoke tests (
    DiffGenerator
    , flux, etc.)
  • Comparing eager vs
    torch.compile
    diffusion performance
  • Verifying
    python[diffusion]
    editable install changes
This environment is already prepared:
  • sglang_bbuf
    is running on
    lmsysorg/sglang:dev
  • the repo is cloned at
    /data/bbuf/repos/sglang
  • editable installs for
    python[all]
    and
    python[diffusion]
    are already done
  • /data/.cache
    is mounted to
    /root/.cache
  • Infiniband paths are mounted for RDMA-aware workflows:
    /sys/class/infiniband
    ,
    /dev/infiniband
    , and
    /usr/sbin/show_gids

Quick Start

  1. Check the host, container, and GPU state.
bash
ssh h100_sglang 'hostname && whoami'
ssh h100_sglang 'docker ps --format "table {{.Names}}\t{{.Status}}" | sed -n "1,20p"'
ssh h100_sglang 'nvidia-smi --query-gpu=index,name,utilization.gpu,memory.used,memory.total --format=csv,noheader,nounits'
  1. Enter the container and confirm HF token visibility.
bash
ssh h100_sglang 'docker exec -it sglang_bbuf /bin/zsh'
cd /data/bbuf/repos/sglang
echo ${HF_TOKEN:+set}
If
HF_TOKEN
is missing, export it before any Hub-backed diffusion run:
bash
export HF_TOKEN=<your-hf-token>
export HUGGINGFACE_HUB_TOKEN="$HF_TOKEN"
For non-interactive
docker exec ... bash -lc "<cmd>"
runs, export both variables inline instead of relying on shell startup:
bash
ssh h100_sglang 'docker exec sglang_bbuf env HF_TOKEN=<your-hf-token> HUGGINGFACE_HUB_TOKEN=<your-hf-token> zsh -lc "..."'
  1. Pick a free GPU.
Use a GPU with
0
utilization and only a few MiB allocated. Always set
CUDA_VISIBLE_DEVICES=<gpu_id>
for diffusion validation commands.
  1. If the container is not running, start it.
bash
ssh h100_sglang 'docker start sglang_bbuf'

Safe Remote Workflow

  1. Inspect the repo state before editing.
bash
ssh h100_sglang 'docker exec sglang_bbuf zsh -lc "cd /data/bbuf/repos/sglang && git branch --show-current && git status --short"'
  1. Fast-forward to latest clean
    main
    before creating a validation worktree.
bash
ssh h100_sglang 'docker exec sglang_bbuf zsh -lc "cd /data/bbuf/repos/sglang && git fetch origin && git checkout main && git pull --ff-only origin main"'
  1. Never write directly into
    /data/bbuf/repos/sglang
    when it is dirty.
  2. Use one of these isolation strategies.
Create a detached worktree for remote-only experiments:
bash
ssh h100_sglang 'docker exec sglang_bbuf zsh -lc "cd /data/bbuf/repos/sglang && git worktree add --detach /tmp/sglang_validate_h100 HEAD"'
Stream the local working tree into the container (validates exactly what is local right now):
bash
COPYFILE_DISABLE=1 tar --exclude=.git -cf - . | \
ssh h100_sglang 'docker exec -i sglang_bbuf sh -lc "rm -rf /tmp/sglang_local_validate && mkdir -p /tmp/sglang_local_validate && tar -xf - -C /tmp/sglang_local_validate"'
ssh h100_sglang 'docker exec sglang_bbuf zsh -lc "find /tmp/sglang_local_validate -name '\''._*'\'' -delete"'
For patch-oriented validation:
  • fast-forward remote
    main
  • create a detached worktree from that commit
  • stream or
    git apply
    only the focused local diff into the worktree
This keeps
/data/bbuf/repos/sglang
clean while still validating the exact local delta.

Diffusion Validation Workflow

1. Syntax / Import Check

Always start here before running any GPU kernel or model test.
bash
ssh h100_sglang 'docker exec sglang_bbuf zsh -lc "cd /tmp/sglang_local_validate && python -m compileall python/sglang/jit_kernel/diffusion/triton python/sglang/multimodal_gen/runtime/layers"'
For broader coverage:
bash
ssh h100_sglang 'docker exec sglang_bbuf zsh -lc "cd /tmp/sglang_local_validate && python -m compileall python/sglang"'

2. JIT Kernel Smoke

Run a targeted smoke script covering the changed primitives before any model-level test.
Cover at least these when relevant:
  • rms_norm_fn
  • RMSNorm
    under
    torch.compile
  • norm_infer
  • apply_rotary_embedding
Pipe the smoke script through
docker exec -i
:
bash
ssh h100_sglang 'docker exec -i sglang_bbuf env CUDA_VISIBLE_DEVICES=0 PYTHONPATH=python python' < /path/to/local_smoke.py

3. Fused Modulation Regression

Run this after any change to
jit_kernel/diffusion/triton
:
bash
ssh h100_sglang 'docker exec sglang_bbuf env CUDA_VISIBLE_DEVICES=0 PYTHONPATH=python zsh -lc "cd /tmp/sglang_local_validate && pytest -q python/sglang/jit_kernel/tests/test_qwen_image_modulation.py -q"'

4. General Diffusion Tests

bash
ssh h100_sglang 'docker exec sglang_bbuf env CUDA_VISIBLE_DEVICES=0 PYTHONPATH=python zsh -lc "cd /tmp/sglang_local_validate && pytest -q path/to/diffusion_test.py -q"'

5. Model-Level Smoke (
DiffGenerator
)

Only after steps 1–4 pass.
Use a real
.py
file with
if __name__ == "__main__":
guard —
multiprocessing.spawn
will fail if the entry point is stdin or unguarded top-level code.
bash
# stream the script file to the container
scp /path/to/local_smoke_model.py h100_sglang:/tmp/smoke_model.py
ssh h100_sglang 'docker exec sglang_bbuf env CUDA_VISIBLE_DEVICES=0 HF_TOKEN=<your-hf-token> HUGGINGFACE_HUB_TOKEN=<your-hf-token> PYTHONPATH=/tmp/sglang_local_validate/python zsh -lc "python /tmp/smoke_model.py"'
Treat checkpoint, dependency, and environment failures separately from code regressions.

6. Server-Level Smoke

Only attempt after model-level smoke passes.
bash
ssh h100_sglang 'docker exec sglang_bbuf env CUDA_VISIBLE_DEVICES=0 PYTHONPATH=python zsh -lc "cd /tmp/sglang_local_validate && python -m sglang.launch_server --model-path <model> --port 30000 &"'

Torch Compile Attribution

When a benchmark compares eager vs
torch.compile
, do not stop at the speedup number. Capture matching eager and compile traces or perf dumps, then run:
bash
ssh h100_sglang 'docker exec sglang_bbuf zsh -lc "cd /tmp/sglang_local_validate && python scripts/analyze_diffusion_torch_compile.py"'

Cleanup

bash
ssh h100_sglang 'docker exec sglang_bbuf rm -rf /tmp/sglang_local_validate /tmp/sglang_validate_h100 /tmp/smoke_model.py'