* Studio: serialise GGUF reload and inherit unsloth-run extra args
Closes#5401.
Three related GGUF reload bugs reproduced against `unsloth studio run -m unsloth/Qwen3-0.6B-GGUF --gguf-variant Q4_K_M --top-k 20 --seed 42`:
1. The `POST /api/inference/load` already-loaded short-circuit only compared `model_identifier` and `hf_variant`. A same-(model, variant) Apply that flipped `cache_type_kv` / `speculative_type` / `chat_template_override` / `max_seq_length` / `llama_extra_args` returned `status="already_loaded"` and the new setting silently never reached llama-server.
2. The frontend chat-settings Apply path POSTs `/unload` then `/load` without round-tripping `llama_extra_args`. Every reload after `unsloth run --some-flag X` quietly dropped `--some-flag X` from the spawned `llama-server` command line.
3. `LlamaCppBackend.load_model` released `_lock` between Phase 1 (kill) and Phase 3 (spawn) so two concurrent loads each passed Phase 1 with `self._process is None`. Both ran Phase 2 (download), both reached Phase 3, and the Phase 3 defensive `_kill_process()` from #5171 collapsed them to one survivor only after both `subprocess.Popen` calls had landed. For the 86 GB MoE in #5161 / the model in #5401 the overlap window was tens of seconds, long enough to OOM the host. With a 0.6B model the pgrep timeline showed two simultaneous PIDs for 3.3 s on `main`.
Fix:
`studio/backend/core/inference/llama_cpp.py`
* Add `self._serial_load_lock = threading.Lock()`. The whole body of `load_model` runs under this lock so two concurrent `/api/inference/load` requests are strictly sequential. The fine-grained `_lock` and the Phase 3 defensive `_kill_process()` from #5171 are kept as a second layer. `/unload`, `/status`, and `/load-progress` are unaffected because they only touch the fine-grained lock or read properties.
* Add `self._extra_args` plus an `extra_args` property, written inside `load_model` whenever the caller supplies a non-`None` value. `unload_model()` deliberately does not reset it so the route layer can inherit the args across the frontend's `/unload` + `/load` gap.
`studio/backend/routes/inference.py`
* Add `_request_matches_loaded_settings(request, llama_backend)` that compares `max_seq_length`, `cache_type_kv`, `speculative_type`, `chat_template_override`, and `llama_extra_args` between the incoming request and the live backend. Same-(model, variant) requests whose runtime settings differ now fall through to a real reload instead of returning `already_loaded`. A missing `llama_extra_args` field on the request is treated as "inherit current", so the short-circuit still fires when the only difference is the frontend not echoing the CLI flags back.
* GGUF load branch inherits `llama_extra_args` from `llama_backend.extra_args` when the request omits the field, re-validates through `validate_extra_args`, and forwards the result to `load_model(...)`. An explicit `[]` from the caller is still honoured as "clear".
Verified end to end against a live `unsloth studio run` instance:
| Scenario | Before | After |
| --------------------------------------------------------------- | --------- | ------------------------------------------------------------------------ |
| `/load` same (model, variant, settings) | 1 PID, `already_loaded` | unchanged |
| `/load` same model, variant, new `cache_type_kv=q8_0` ctx=8192 | `already_loaded`, settings dropped | `loaded`, `/status` reports the new settings, new server has `-c 8192 --cache-type-k q8_0 --top-k 20 --seed 42` |
| Frontend Apply `/unload` + `/load`, new settings, no `llama_extra_args` field | Drops `--top-k 20 --seed 42` | Preserves `--top-k 20 --seed 42` |
| `/unload` + two parallel `/load` | Two PIDs for 3.3 s | Max simultaneous count = 1 across the full pgrep timeline |
| `/load` with `llama_extra_args=[]` (explicit clear) | n/a | `loaded`, new server has no `--top-k` / `--seed` |
| `/load` with `llama_extra_args=["--top-k","30","--seed","7"]` (override) | n/a | `loaded`, new server has the supplied flags |
`pytest studio/backend/tests` is green except for one pre-existing terminal-width-sensitive assertion (`test_studio_api.py::test_help_output`) and the pre-existing `test_studio_api.py` fixture errors that fail on unmodified main too. No new regressions.
* Studio: track requested n_ctx so Auto-slider flips trigger a reload
Review feedback on PR #5427 from gemini-code-assist.
The original short-circuit compared ``request.max_seq_length`` against
``llama_backend.context_length`` (the effective context). VRAM-fit
logic can cap the running server below what the caller asked for, so
this comparison incorrectly returns ``already_loaded`` when the user
flips the slider from an explicit length (e.g. 8192) back to "Auto"
(0): the explicit request was capped to, say, 4096, and the new "Auto"
request reads ``backend.context_length == 4096`` and decides nothing
changed.
Track the originally requested ``n_ctx`` on the backend instead and
compare against that. ``requested_n_ctx == 0`` means the last load
asked for the model's native length; ``request.max_seq_length == 0``
matches it.
Verified in the sandbox suite (now 90 tests):
- ``test_explicit_to_auto_triggers_reload`` -- loaded with explicit
8192, then Apply with ``max_seq_length=0`` falls through to a real
reload and the new server runs at the native 40960.
- ``test_auto_to_explicit_triggers_reload`` -- inverse direction.
- ``test_explicit_to_same_explicit_short_circuits`` -- re-Apply with
the same explicit value still short-circuits (no needless reload).
- Existing scenarios (kv change, spec change, template change, extra
args inherit, parallel-load stress, frontend Apply flow) unchanged.
``pytest studio/backend/tests`` still green on the same set of tests;
the pre-existing ``test_help_output`` failure and ``test_studio_api``
fixture errors are unaffected.
* Studio: tighten comments in the 5401 fix
Trim the verbose explanatory comments and docstrings introduced in
f9cbec3b and dd0b1d58 down to one-line summaries. The "why" still
points at issue #5401; the multi-paragraph rationale belonged in the
PR body, not the source. No behaviour change.
* ci: retrigger after zoo drift + IPython fixes landed in main
* ci: retrigger Mac Studio UI CI after transient fetch flake
* Studio: address six P2 followups on the 5401 reload PR
Tightens the inheritance and serial-load paths to close the six P2
findings raised by codex-connector on PR #5427 against `f9cbec3b` /
`dd0b1d58`.
1. Re-check loaded state before killing queued loads. Two duplicate
`/api/inference/load` requests both pass the route-level
`is_loaded` gate before the first publishes `_healthy = True`. The
second waits on `_serial_load_lock`, enters Phase 1, and tears down
the just-spawned llama-server for a redundant full reload. Added
`LlamaCppBackend._already_in_target_state(...)` and a short-circuit
at the top of the serial-lock block: if the live server already
satisfies the kwargs, return True without killing.
2. Don't inherit CLI overrides that shadow new first-class settings.
`unsloth run -c 4096` is a permitted pass-through; the validator
docs explicitly call out `-c`/`--ctx-size`. Stored in `_extra_args`
and appended after Studio's own flags, the inherited `-c 4096`
silently won the last-wins parse against a new
`max_seq_length=8192`. Added `strip_shadowing_flags` in
`llama_server_args.py` (covers `-c`, `--cache-type-k/v`, `--spec-*`,
`--chat-template*`, `--jinja`/`--no-jinja`) and the route runs the
inherited list through it before validate + forward.
3. Restrict inherited llama args to the same GGUF model. `_extra_args`
is deliberately preserved across `unload_model()` for the chat-
settings Apply flow (`/unload` + `/load` with no `llama_extra_args`
field). Now also track `_extra_args_source = (model_identifier,
hf_variant)` so the route can refuse cross-model inheritance.
`LlamaCppBackend.extra_args_source` exposes the tuple.
4. Persist extras only after a successful load. `_extra_args` was
written at the top of `load_model` before Popen + health check, so
a failed startup left bad args in place to poison the next UI
retry. The write (along with `_requested_n_ctx`) is now deferred
until after `_healthy = True`.
5. Ignore speculative diffs for vision loads. `load_model` silently
gates speculative decoding on `not is_vision`, so the backend's
`_speculative_type` stays `None` for vision models. The route's
comparator now normalises the request's value to `"off"` when
`llama_backend.is_vision` to avoid a no-op reload of a vision
server every time the dropdown defaults to `default`. The
`_already_in_target_state` helper applies the same rule.
6. Wait for the replacement server before short-circuiting. `_kill_process`
did not clear `_healthy`; the new first-class settings
(`_cache_type_kv`, `_speculative_type`, `_chat_template_override`)
are written under `_lock` BEFORE Popen + `_wait_for_health`. A
duplicate `/load` arriving during the new server's warm-up window
could short-circuit against the not-yet-healthy replacement and the
caller would start inference against a server that was still
loading. `_kill_process` now sets `_healthy = False` in its
`finally` block so `is_loaded` returns False from the moment the
old server is killed until the new one finishes warm-up.
Tests:
- Sandbox suite under `./temp/sim_5401/` extended to 136 tests (was
90): new unit coverage for `strip_shadowing_flags` (12 cases),
`_kill_process` clears `_healthy`, `extra_args_source` lifecycle and
cross-model behaviour, failed-load preserving prior extras, and the
duplicate-load short-circuit at `load_model` level. New live
integration cases verify shadow-strip via `pgrep` on the live
llama-server cmdline, cross-model refusal, and PID stability across
a duplicate-load race. All 136 pass.
- `pytest studio/backend/tests --deselect test_studio_api.py`:
1079 passed, 46 skipped, identical to the pre-change count. The
pre-existing `test_studio_api.py` fixture errors and the
terminal-width-sensitive `test_help_output` are unaffected.
- Ruff: clean on the three modified files.
* Studio: tighten GGUF reload inheritance and duplicate-load guard
Re-narrow llama_extra_args to None after validate_extra_args when the
incoming request omitted the field, so the backend can distinguish
"caller omitted, inherit prior load" from "caller explicitly cleared
to []". Without this a queued duplicate /load reaches the backend as
[] and fails _already_in_target_state's exact-equality check, killing
the just-started llama-server. The pass-through validate call from
the original "forward llama-server args from unsloth studio run /
unsloth run" change is preserved as-is; only the post-pass narrowing
is new. Cross-source loads now explicitly clear extras so a model
switch can't accidentally inherit via the backend's "no opinion"
semantics.
Store the caller's hf_variant kwarg (None for local GGUF files) in
_extra_args_source instead of the derived self._hf_variant
(an extracted filename quant label like "Q4_K_M"). Same-source check
in the route is now symmetric for HF and direct-file loads.
Add gguf_path to _already_in_target_state and prefer on-disk path
identity when both backend and caller have a path. This stops the
duplicate-load guard from killing a healthy server on repeat local
loads (where hf_variant is None on the caller side but extracted on
the backend side).
Split shadow-flag stripping into per-group toggles (context / cache /
spec / template). The route now opts into stripping only the groups
whose first-class field was actually set on the incoming request, so
an inherited --chat-template-file survives an Apply that omits
chat_template_override. _request_matches_loaded_settings detects
shadowing extras on the inherit path and falls through to a real
reload so the strip can run.
Mark --spec-default, --jinja, --no-jinja as boolean inside the
shadow stripper so the value-consuming heuristic no longer eats the
following positional token.
* Studio: trim comments around GGUF reload inheritance
* Studio: cover GGUF reload inheritance and shadow-flag stripping
* Studio: drop redundant issue refs from inheritance comments
* Studio: drop redundant issue refs from inheritance comments
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* Studio: key inheritance source off resolved gguf_variant
codex-connector P2 on PR #5427cd14cae1: the inheritance gate at
``routes/inference.py:696`` compared the stored ``source[1]`` against
``request.gguf_variant``, but the HF branch loaded with
``hf_variant = config.gguf_variant`` (the *resolved* variant after
ModelConfig auto-pick). When the caller omitted ``gguf_variant`` on a
follow-up Apply, ``source[1] == "Q4_K_M"`` but
``(request.gguf_variant or "") == ""``, ``same_source`` returned False,
and the chat-settings Apply silently dropped CLI pass-through flags
for every auto-pick / local-file load.
Fix both sides of the comparison to key off ``config.gguf_variant``:
* The route compares ``source[1]`` to ``config.gguf_variant`` (the
resolved label) rather than the request field.
* The local-mode load_model call now passes
``hf_variant = config.gguf_variant`` so ``_extra_args_source``
stores the same string the route reads back. The HF branch already
did this.
Sandbox: added test_source_records_caller_variant_not_extracted_label
to lock the storage key contract.
``pytest studio/backend/tests --deselect test_studio_api.py``:
1100 passed, identical to pre-change.
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* Studio: deny upstream --ui family on llama-server pass-through
The validator's web-UI block named only ``--webui`` / ``--no-webui``,
which is llama.cpp's pre-rename spelling. Current upstream
(``tools/server/README.md``) uses ``--ui`` / ``--no-ui`` plus
``--ui-config``, ``--ui-config-file``, and ``--ui-mcp-proxy`` /
``--no-ui-mcp-proxy``. Without these in the denylist a user could
``unsloth run --ui`` and enable llama-server's built-in web UI on
the port Studio's reverse proxy targets, breaking the UI surface.
Keep the legacy ``--webui`` group so the validator still rejects
old binaries that haven't been re-spelled.
Cross-referenced against the README's full flag list; this was the
only gap for the post-#5401 inheritance / shadow-strip work. Pass-
through flags from every other README category (sampling, jinja,
ctx, cache, threads, GPU, reasoning, grammar, chat-template-kwargs)
already validate cleanly; sandbox suite exercises ~60 of them in
the new ``test_08_llama_server_pass_through.py``.
``pytest studio/backend/tests --deselect test_studio_api.py``:
1100 passed, identical to pre-change.
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