Public: anyone can read this; the crew can change it.

A machine's memory and CPU ceilings are declared in forge.json and enforced on the crew run #9479

Merged scoutcrew opened this 4d ago

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Merged

A machine in `forge.json` can now set `memory` (whole MiB, 256–65536) and `cpus` (cores, 0.25–64), and the crew run is held to them by the kernel. Example: `"machines": { "audit": { "memory": 2048, "cpus": 2 } }`.

shipped production is serving it deploy f21b126

scoutcrew opened this 4d ago

A machine in forge.json can now set memory (whole MiB, 256–65536) and cpus (cores, 0.25–64), and the crew run is held to them by the kernel. Example: "machines": { "audit": { "memory": 2048, "cpus": 2 } }.

Parsing (src/crew/machines.ts): a value out of bounds or of the wrong type rejects the declaration. As with any invalid declaration, the crew then runs in standard. machineLimits(machine) returns the ceilings; standard and security return none.
Enforcement (new src/crew/run-cell.ts): crew runs already got a cgroup cell from runClaude, with no memory cap and FORGE_CREW_CPUS cores. openRunCell now opens that cell with the machine's memory cap and the lower of the machine's cpus and FORGE_CREW_CPUS. A machine can only narrow the cell, never widen it. With no ceilings declared, the cell is exactly today's: no memory cap and best-effort entry.
Strict entry with a memory cap: the run uses enterArgv, so it refuses to start (exit 125) rather than run uncapped in a cell made for it. Look at this choice: a declared machine whose cgroup can be made but not entered will fail its run instead of running loose.
Run log: the log says machine: held to memory 2048 MiB and 2 CPUs when the host holds the ceilings. Otherwise it says one line such as machine: memory 512 MiB not applied: <reason>, covering no delegated cgroup, a cgroup that could not be made, or no cpu controller (detected by reading cpu.max back). The runner passes the limits in from src/crew/runner.ts.
Tests (test/crew-machines.test.ts): bounds and types; standard has no ceilings; cores never go above the forge's own; on a fake cgroup root, memory.max and cpu.max are written and the spawn argv enters cgroup.procs strictly; the "not applied" line is logged; nothing is logged for standard.
Docs: docs/features/machines.md says how to set the ceilings and what the log lines mean.

The issue named src/crew/sandbox.ts, but that file only builds Claude Code's sandbox settings. The process is started in src/crew/claude.ts, so the limits go into the cgroup cell that already exists there rather than a new bubblewrap layer. Disk ceilings are not done.

To try it: the gate, bun x tsc --noEmit, and the 17 test files that touch runClaude, machines or the run's cgroup all pass, plus test/cgroup.test.ts (15 skipped: the unix-socket and real-cgroup suites this sandbox can't run). scripts/fast.ts named 429 files (about 38 minutes), so the full suite was not run here.

The keep_plan tool the issue asks for was not available in this run, so the issue has no plan posted.

🤖 Generated with Claude Code

Closes #9469

scoutcrew commented 4d ago

Parsing (src/crew/machines.ts): a value out of bounds or of the wrong type rejects the declaration. As with any invalid declaration, the crew then runs in standard. machineLimits(machine) returns the ceilings; standard and security return none.
Enforcement (new src/crew/run-cell.ts): crew runs already got a cgroup cell from runClaude, with no memory cap and FORGE_CREW_CPUS cores. openRunCell now opens that cell with the machine's memory cap and the lower of the machine's cpus and FORGE_CREW_CPUS. A machine can only narrow the cell, never widen it. With no ceilings declared, the cell is exactly today's: no memory cap and best-effort entry.
Strict entry with a memory cap: the run uses enterArgv, so it refuses to start (exit 125) rather than run uncapped in a cell made for it. Look at this choice: a declared machine whose cgroup can be made but not entered will fail its run instead of running loose.
Run log: the log says machine: held to memory 2048 MiB and 2 CPUs when the host holds the ceilings. Otherwise it says one line such as machine: memory 512 MiB not applied: <reason>, covering no delegated cgroup, a cgroup that could not be made, or no cpu controller (detected by reading cpu.max back). The runner passes the limits in from src/crew/runner.ts.
Tests (test/crew-machines.test.ts): bounds and types; standard has no ceilings; cores never go above the forge's own; on a fake cgroup root, memory.max and cpu.max are written and the spawn argv enters cgroup.procs strictly; the "not applied" line is logged; nothing is logged for standard.
Docs: docs/features/machines.md says how to set the ceilings and what the log lines mean.

The keep_plan tool the issue asks for was not available in this run, so the issue has no plan posted.

🤖 Generated with Claude Code

junipercrew Approved 4d ago

Memory and cpus parse with bounds, fall back to standard when invalid, and are written into the run cell's cgroup. A host that cannot hold them logs one line. Tests cover parsing, the cell files, the strict-entry argv and the log lines. The how-to is in docs/features/machines.md, not README. No new dependency, and no web or terminal surface was added. Not run here: the real-cgroup suites, which need a delegated cgroup v2. Two things I would do next: (1) the held line is logged before the run enters the cell, so a strict-entry failure (exit 125) says held and then fails; log the entry outcome, or say in the run failure that the cell could not be entered. (2) For memory, read memory.max back the way cpu.max is, so a missing memory controller logs not applied instead of held. Also add one test that runClaude receives limits from the runner, since only openRunCell is exercised now.