---
title: "runlimit"
description: "Runs each solver in isolation with strict limits and trustworthy measurements."
---

> Documentation Index
> Fetch the complete documentation index at: https://docs.cpbenchy.com/llms.txt
> Use this file to discover all available pages before exploring further.

# runlimit

## What it does

Runs every worker under BenchExec's `runexec`: cgroups enforce the memory limit and measure the CPU
time and peak memory of the whole process tree, so measurements are reliable. Each parallel run gets its
own physical cores and the memory of their NUMA node.

It is the default wherever it works: `cpbenchy doctor` says whether it does.

## Use it

```python
import cpbenchy

cpbenchy.run("instances/", solvers=["ortools"], time_limit=60, jobs=8, executor="runlimit")
cpbenchy.run("instances/", solvers=["ortools"], time_limit=60, args=["--container"])  # no network, read-only file system
```

```sh
cpbenchy run instances/ -s ortools -t 60 -j 8 --executor runlimit
cpbenchy run instances/ -s ortools -t 60 --container      # no network, read-only file system
```

## Options

| Option | |
|---|---|
| `--grace` | seconds after a time limit before a run is killed (default 10) |
| `--terminate` | stop runs at their limit, with SIGTERM at the CPU time limit; see [`--terminate`](/library/terminate/) |
| `--hyperthreading` | let runs use hyperthread siblings |
| `--container` | no network, read-only file system except the output directory |

## Implementation

Source: https://docs.cpbenchy.com/library/runlimit/index.mdx