[karya0]

Guard preparation (NIXL init + pool registration) no longer blocks the claim response; promotion waits for it instead, and the Guard core startup budget defaults to 60 s and can be raised with --startup-timeout-seconds (KVCRConfig.startup_timeout_seconds). Cores released during registration are kept and closed once registered; a release never waits. Preparation failure remains service-fatal.

Host pools are registered pinned by default: the quick-start image no longer sets UCX_REG_NONBLOCK_MEM_TYPES, and the dev-guide explains why ODP is not recommended. With ODP, registering a 50 GiB pool failed intermittently with EBUSY under memory compaction; without it, the first registration of a 150 GiB Guard pool takes 12–19 s on an 8-CPU sidecar, more than the claim path could absorb.

[Copilot]

🟡 Changes recommended

Deferred cleanup can lose live cores after repeated releases or close failures, allowing pool memory to be unmapped before native resources are released.

2 open issues

• Track multiple pending orphan cores during release · New
• Retain orphan reference until close succeeds · New

What changed in this PR

This PR moves Guard memory registration off the claim path, allowing claims to return while preparation continues and making promotion wait for completion.

Changes:

• Prepare Guard cores asynchronously and defer cleanup when release occurs during registration.
• Scale the default startup budget by registered memory size.
• Remove quick-start ODP settings and document pinned registration behavior.

File	Description
tests/​unit/​test_progress.py	Tests startup budgets, preparation failures, and close behavior.
tests/​unit/​test_guard.py	Tests asynchronous preparation, promotion waits, and deferred release cleanup.
src/​kvcr/​progress.py	Adds nonblocking preparation and size-based startup budgets.
src/​kvcr/​guard.py	Starts background preparation and tracks deferred core cleanup.
docs/​dev-guide.md	Documents startup timing, pinned registration, and ODP limitations.
Dockerfile.quick-start	Removes environment settings that enabled ODP.

_{Review effort: Balanced}