The daemon spawns every nested claude as a plain child, so its cgroup is
already the "all subagents" cgroup — but it ran with MemoryHigh=infinity
and MemoryMax=infinity, so nothing slowed a subagent down before the
kernel's OOM killer stopped the unit and cut every live session with it.
MemoryHigh= and not MemoryMax=: a soft ceiling reclaims and stalls the
cgroup past two thirds of the container's cap, which turns a silent kill
into a visible throttle, while still letting a single subagent exceed its
share when the container has memory free. A hard per-agent cap would make
overprovisioning impossible, which is not wanted — most of the time
nothing in these sessions is compiling.
The fraction is taken from hyperhive.claudeMemoryMaxBytes, the container's
own effective MemoryMax= that meta.rs already bakes in per agent. When
that is null (an `infinity` or percentage cap) the unit renders no ceiling
rather than a fabricated constant, and module-eval pins both arms.
Refs #4316
4daab7efe4