- Step cache 'Off' is preserved: the frontend defaulted to 'off' and mapped it
to an omitted transformer_cache, which the backend now reads as 'auto', so
leaving the control at Off silently enabled FBCache on 20+ step families.
Default the control to Auto, add an explicit Auto option, and send
auto -> omitted so Off maps to an explicit cache-off.
- Kernel auto-install adds --no-deps: 'pip install --only-binary :all: xformers'
resolves xformers' pinned torch and replaces the running torch/triton. --no-deps
installs only the best-effort kernel wheel; an ABI mismatch just fails to import
and falls back to native, never clobbering core deps.
- Do not retry a failed kernel install under the load lock: the pre-install runs
outside the locks, then the in-lock resolve re-attempts pip (up to 600s) while
holding _generate_lock/_lock and blocking unload/cancel/new loads. Record the
attempt in a process-level set so the in-lock call short-circuits to native.
- Cache auto-toggle keys on effective denoise steps: an image-conditioned run with
strength < 1 (upscale default 0.35) denoises a fraction of the requested steps,
so a 28-step request runs ~10 steps. Compute the effective count the way diffusers
get_timesteps does and gate FBCache on it, only when strength is actually applied.
A successful on-demand wheel install writes into site-packages after the
import system already cached that directory's listing, so the very next
find_spec / import in the same process can miss the freshly installed
package when the install lands within the directory mtime's resolution.
That silently falls set_attention_backend back to native on first use.
Call importlib.invalidate_caches() after a successful install so the
kernel is picked up immediately, and cover both the success and failure
paths in the attention installer tests.
Review follow-ups on the image-generation PR:
- ControlNet: resolve_controlnet accepts a bare owner/name repo without the
non-GGUF base trust gate, and _controlnet_pipe hands it straight to
from_pretrained. A malicious pickle .bin would deserialize on load, so run
the same Hugging Face malware preflight (evaluate_file_security) the chat and
export loaders use before any remote ControlNet load; local dirs are exempt.
- Dataset thumbnails: key the cache on the full filename instead of the stem so
sample.png and sample.jpg no longer collide on one .thumbs file (which could
serve or delete the wrong image); the delete cleanup globs the same key.
- Diffusion training start: mirror start_training's API-key guard so an API
client cannot start training (which frees VRAM by unloading chat) while an
inference request is streaming; it now returns 409 before any GPU is freed.
- Model picker: include the curated safetensors row keys in the recommended
roving key list so arrow-key navigation reaches those rows instead of hitting
the duplicate option-missing id.
Tests: ControlNet malware gate (remote blocked before from_pretrained, local
skipped), thumbnail same-stem cache separation, API-key diffusion-start 409
before GPU free. Full diffusion suites green.
The latent cache holds two fp32 posterior tensors per crop/flip variant per
image, pinned on CUDA hosts, so datasets with thousands of images can exhaust
host or pinned memory with no fallback. Estimate the cache size from the first
real encoded latent and fall back to per-step VAE encoding when it exceeds a
4 GiB budget. UNSLOTH_DIFFUSION_FORCE_LATENT_CACHE bypasses the gate; the
existing UNSLOTH_DIFFUSION_NO_LATENT_CACHE opt-out is unchanged.
Replace the with-replacement per-batch index draw in the SDXL and DiT LoRA
trainers with a shared PermutationBatchSampler that visits every image once per
cycle before repeating, so short runs cover the whole dataset. The sampler
reshuffles from the run's rng so the index stream stays seed-deterministic.
Guard the diffusion run detail route against a valid-JSON non-object record,
which previously raised TypeError and returned a 500; it now 404s like the list
path's shape check.
Add regression tests for both.
The run detail route built DiffusionTrainingRunDetail(**rec) unguarded, so a
valid-JSON-but-wrong-shape record (hand-edited or an older schema) would 500
instead of reading as absent. Catch ValidationError and 404, matching how the
list route skips malformed records.
A dual-DiT pipeline (Ideogram 4's unconditional tower) placed its second
denoiser resident under the group tier, which defeats the tier since the
pair rarely fits where one alone did not. Stream transformer_2 and
unconditional_transformer alongside the transformer and keep only the
smaller companions resident.
The perf rewrite dropped the bf16 capability guard, so a pre-Ampere CUDA
device (T4/V100/RTX 20xx) would die deep in model load with an opaque dtype
error instead of a clear message. Restores parity with the SDXL trainer.
