Spec for two new clamps on the existing inference_thread_count helper:
- Battery clamp: drop to physical/2 when on battery (Linux sysfs probe;
macOS/Windows return Unknown, treated as OnAc).
- GPU-offload clamp: 2 threads for fully-offloaded LLM, 4 for Whisper
(Whisper keeps mel spectrogram, decoder bookkeeping, and beam search
on CPU even with full Vulkan offload).
Codex + online-research consult: no prior art in llama.cpp, Ollama,
Jan, or mistral.rs. Apple's Low Power Mode is OS-level (P-core
frequency cap), not a published software API. Lumenote would be first
in the open Rust inference-wrapper space; instrumentation matters,
hence the thread_sweep.rs extension + per-process INFO log.
Architecture (Approach B):
- New crates/core/src/power.rs (PowerState, sysfs probe, 10s TTL).
- New crates/core/src/tuning.rs (Workload enum, helper).
- Move vulkan_loader_available() from src-tauri to magnotia-core
so crates/transcription can call it without a Tauri dep.
- Existing constants::inference_thread_count() becomes deprecated
facade for one commit, then removed.
GPU-offload detection is intent-based (use_gpu && requested_layers
>= model.n_layer() for LLM; cfg(whisper-vulkan) && libvulkan
resolvable for Whisper). Residency-based detection deferred:
llama-cpp-2 0.1.145 doesn't expose post-load offload count, so a
true outcome flag would need llama_log_set callback parsing or an
upstream PR. Caveat documented in the spec.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
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