Two remaining pieces of the two-application coupling are gone.
Overclock profiles were switched by naming 'comfy' and 'ollama' directly, so a third
application could never get tuned clocks. A tenant declares overclock_profile and the
arbitrator applies whichever the highest-priority *working* tenant asks for, falling
back to the idle profile when nothing is running.
The websocket listener parsed ComfyUI's message schema -- status, execution_start,
executing, execution_success -- which tied the fast path to one application. An event
source is now declarative and the messages are not parsed at all: any message means
"look now", and the tenant's own busy probe decides what is true. That gives the same
sub-second reaction to any application that emits anything on state change, with no
knowledge of what it emits.
Generalising this exposed a design error in the priority rule I had introduced.
plan_release excluded candidates ranking above the demander, which broke both
directions in turn. With the LLM at priority 60 and diffusion at 50, ComfyUI could
never reclaim from Ollama -- the premise the whole service is built on, and preserved
until now only by the ComfyUI-specific trigger that was about to be removed. Swapping
the ranks then broke the reverse: a starved Ollama could no longer reclaim from an
idle ComfyUI.
Priority now orders rather than vetoes. Any idle reclaimable tenant is a candidate,
because an idle tenant is not using its VRAM; priority decides who is asked first, and
busy tenants are never interrupted whatever their rank. Diffusion outranks the LLM,
whose weights reload from page cache in seconds. All three cases are pinned by tests,
including that busy work is never interrupted even by a far higher-priority demander.
Tests: 244 (was 242).
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
The point of this service is fast handoff of one GPU between applications. It grew up
around the two on this box, and their names ended up compiled into process matching,
VRAM attribution, busy detection and release calls alike -- about 385 references
across five modules. That made it a script for Ollama and ComfyUI rather than a GPU
arbitrator.
tenants.py describes an application as data: how to recognise its processes, how to
tell whether it is genuinely working, how to ask it for VRAM back, and how much it
matters when two want the card. Ollama, ComfyUI and the desktop compositor ship as
defaults in tenants.json, so behaviour is unchanged, but the arbitration logic no
longer knows any particular name. Endpoints are generic: GET /api/tenants,
GET /api/tenants/{name}, POST /api/tenants/{name}/release -- the last being the
general form of both the Ollama soft-yield and the ComfyUI purge.
Verified by registering a third application on this machine with no code change: the
speech relay that had been showing up only as anonymous "unmanaged VRAM" is now named,
attributed, and probed by the VRAM it holds rather than by an API it does not have.
Because it declares no release strategy, a release request returns 409 explaining that
its memory cannot be reclaimed, instead of reporting a success that did nothing.
Busy probes deliberately cannot use GPU utilisation. It is shared by every tenant, so
it cannot attribute work to one of them -- the mistake that made a stale ComfyUI queue
entry undetectable earlier in this branch. A tenant's own VRAM is the signal.
Writing the tests exposed that the suite had become non-hermetic: classification is now
configuration, so a test asserting "a third-party process is unmanaged" started failing
the moment the speech relay was registered on this machine. An autouse fixture now
isolates every test from the operator's live tenants.json.
Tests: 231 (was 206).
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
