Systematic audit of all 18 scheme-serving daemons for the acpid failure
class (single-threaded daemon that can wait unboundedly in its serving
thread). Findings recorded in INIT-NAMESPACE-MANAGER-SCALABILITY-PLAN.md:
- acpid was the ONLY software unbounded wait in the boot-critical path
(fixed). No other boot-path handler has an unbounded software wait or a
reentrant blocking open of another scheme.
- Hardware busy-waits (rtcd/ps2d/audio/gpu register polls) are
hardware-bounded or in daemons pcid does not spawn without the device.
- ucsid is the one remaining co-victim: it reads /scheme/acpi in
build_state() before publishing its scheme and is the only blocking,
acpi-dependent boot unit in redbear-mini. It already degrades on EAGAIN
and works with acpid fixed. It must NOT be flipped to oneshot_async
(that breaks ucsi scheme registration, which init performs via the
{scheme=…} type); the correct hardening is a source refactor
(publish-then-discover), done with runtime validation, not blind.
vasilito
9f1a10937f