The Studio installer skipped Flash Attention on any Blackwell GPU
(compute capability >= 10.0: sm_100 B200/B100, sm_120 RTX 50 series),
on the assumption that no prebuilt wheels existed for those archs. That
assumption is stale: Dao-AILab has shipped wheels with sm_100 / sm_120
kernels since flash-attn v2.7.3, built for CUDA >= 12.8.
Replace the blanket has_blackwell_gpu() skip in _ensure_flash_attn and
_ensure_flash_attn_for_long_context with a CUDA-version-aware gate. The
normal prebuilt-wheel path already builds the exact wheel URL, HEAD-checks
it, and falls back gracefully, so it now runs on Blackwell unless the
installed torch's CUDA build is older than 12.8 (in which case the
matching wheel would lack Blackwell kernels and crash at kernel launch).
- wheel_utils: probe now reports full cuda_version; add
cuda_supports_blackwell_flash_attn and should_skip_flash_attn_for_blackwell.
- install_python_stack / training worker: use the new gate.
- Update the corresponding tests.
Raise ruff line-length to 100 and extend the local pre-commit format pipeline (def-signature magic-comma normalization, short multi-line assert collapse, kwarg '=' spacing, blank-line-after-short-import removal, adjacent string-literal / f-string+plain merge, redundant-pass pruning). Every transform re-checks the file AST and is dropped if it would differ; the whole-repo reformat is verified AST-identical per file and idempotent.
* studio: skip flash-attn install on Blackwell GPUs (sm_100+)
Dao-AILab does not publish prebuilt flash-attn wheels for sm_100, sm_120,
or sm_121, and the older-arch wheels fail to load on Blackwell. Add a
shared has_blackwell_gpu() helper and gate both the install-time
(install_python_stack._ensure_flash_attn) and runtime
(worker._ensure_flash_attn_for_long_context) paths on it. Detection uses
nvidia-smi --query-gpu=compute_cap, which works on Linux and Windows.
* test: stub has_blackwell_gpu in pre-existing runtime flash-attn tests
prefers_prebuilt_wheel and falls_back_to_pypi exercise the install
paths that the Blackwell guard now short-circuits. Make them explicit
about non-Blackwell so they pass on real Blackwell hosts.
* studio: cache has_blackwell_gpu, skip Blackwell warning under NO_TORCH
- Wrap has_blackwell_gpu in functools.lru_cache so repeated calls in a
single process avoid redundant nvidia-smi spawns. Tests clear the
cache via setup_method/teardown_method.
- In _ensure_flash_attn, run the NO_TORCH short-circuit before the
Blackwell check so GGUF-only users (who never install torch anyway)
do not see a Blackwell warning. Blackwell check still runs above the
IS_WINDOWS / IS_MACOS gates so Blackwell-on-Windows users still see
the explicit reason rather than a silent OS skip.
* [pre-commit.ci] auto fixes from pre-commit.com hooks
for more information, see https://pre-commit.ci
* test: add has_blackwell_gpu to mlx worker test wheel_utils stub
test_mlx_training_worker_config loads worker.py against a hand-rolled
utils.wheel_utils stub. Adding has_blackwell_gpu to the stub symbol
list so worker's import line resolves.
---------
Co-authored-by: pre-commit-ci[bot] <66853113+pre-commit-ci[bot]@users.noreply.github.com>
* [Studio] Install flash attn at setup time for linux
* [pre-commit.ci] auto fixes from pre-commit.com hooks
for more information, see https://pre-commit.ci
* cleanup changes
Signed-off-by: Datta Nimmaturi <venkatadattasainimmaturi@gmail.com>
* [pre-commit.ci] auto fixes from pre-commit.com hooks
for more information, see https://pre-commit.ci
* Test cases
* wheel_utils: narrow url_exists exceptions and log at debug level
---------
Signed-off-by: Datta Nimmaturi <venkatadattasainimmaturi@gmail.com>
Co-authored-by: pre-commit-ci[bot] <66853113+pre-commit-ci[bot]@users.noreply.github.com>
Co-authored-by: Roland Tannous <115670425+rolandtannous@users.noreply.github.com>
Co-authored-by: Roland Tannous <rolandtannous@gravityq.ai>
