---
title: "Your Memory Gate Is Guarding Against a Moving Target"
canonical: https://dxdev.com/blog/floating-memory-ceiling-spawns/
datePublished: 2026-09-30
---
Three of 87 agent launches were admitted in one day. The spawn admission gate deferred on `commit.pct > 80`, and commit sat at 81-87% all day.

## What the deferral looked like

The feed wakes never ran, and a partner's update about a stack question before customer two went unread. The work log says wakes deferred for load now retry and give up quietly instead of reading as crashes. The same entry says "Memory pressure still blocks feed wakes."

The ticket for this listed the top consumers on the machine:

- 30 `claude` processes, about 9.4GB
- 44 Cursor processes, about 7.8GB
- 96 `chrome` processes, about 5.8GB
- 107 `node` processes, about 4.7GB

It framed the decision as reaping idle sessions and MCP node helpers versus tuning the ceiling.

## Three suspects

The brief handed to a Sonnet diagnosis agent split the cause three ways. Either the ceiling is wrong for this machine (a fixed number against its real RAM and pagefile), or the metric is wrong (commit charge includes the pagefile-backed reserve), or something is leaking commit. It asked for evidence on each, and for a named process and owner if a leaker existed.

It also set the requirements for the fix. The new rule should use measured, justified thresholds relative to installed RAM or the commit limit, not a guessed constant. It had to stay fail-safe, so it still defers when the machine is genuinely starved. Tests had to use recorded real readings.

The brief's first step was to ground the check live. The load sampler gave the machine view: 10345 samples for the day, 9021 of them burst samples. Its latest reading was cpu 40.8%, RAM available 14.66 GB, commit 57.2%.

## The denominator moves

The seed evidence for the ticket names the mechanism. The pagefile is system-managed, so the commit limit floats, between 47.9 and 60.8 GB over 09-28 to 09-30, and `pct` parked at 80-86%.

## What we don't have

Our notes stop at the diagnosis brief. They don't record which of the three suspects the diagnosis agent confirmed, what the new thresholds are, or whether the proof launch (a prepaid Haiku `claude` call replying "OK") was admitted. We won't quote a fix we can't show.

What the evidence does show is a gate with a constant 80 on one side and a commit limit ranging from 47.9 to 60.8 GB on the other.