Learn how to set the stack limit on WSL2 permanently using the prlimit command and the /etc/systemd/user.conf file.
Table of Contents
Problem
If you are using Windows Subsystem for Linux 2 (WSL2), you may encounter some issues with the stack size limit. The stack size is the amount of memory allocated for each thread to store local variables, function parameters, return addresses, and other temporary data. By default, the stack size limit on WSL2 is 8192 KB, which may not be enough for some applications or scripts that require a large amount of stack space.
In this article, we will show you how to set the stack limit on WSL2 permanently using two methods: the prlimit command and the /etc/systemd/user.conf file.
Method 1: Use the prlimit command
The prlimit command is a Linux utility that allows you to get and set the resource limits of a running process. You can use it to change the stack size limit of the current shell or any other process by specifying its process ID (PID). To use the prlimit command, you need to install the util-linux package, which contains various system utilities. You can install it using the following command:
sudo apt update && sudo apt install util-linux
To set the stack limit to unlimited for the current shell, you can use the following command:
sudo prlimit --stack=unlimited --pid $
The $$ variable represents the PID of the current shell. You can check the stack limit by using the ulimit -s command, which should show unlimited.
However, this method only changes the stack limit for the current shell session. If you close the shell or open a new one, the stack limit will revert to the default value of 8192 KB. To make the change permanent, you need to use the second method.
Method 2: Edit the /etc/systemd/user.conf file
The /etc/systemd/user.conf file is a configuration file for the systemd user manager, which controls the user session and the user services. You can edit this file to set the stack limit for all the user processes. To edit the file, you need to use a text editor such as nano, vim, or emacs. For example, you can use the following command to open the file with nano:
sudo nano /etc/systemd/user.conf
In the file, you need to find the line that starts with #DefaultLimitSTACK= and uncomment it by removing the # symbol. Then, you need to change the value after the = sign to the desired stack limit in bytes. For example, to set the stack limit to unlimited, you can use the following value:
DefaultLimitSTACK=infinity
Alternatively, you can use a specific value in bytes, such as 16 MB:
DefaultLimitSTACK=16777216
After editing the file, you need to save it and exit the text editor. Then, you need to restart the WSL2 instance for the changes to take effect. You can do this by using the following command in PowerShell:
wsl --shutdown
Then, you can launch WSL2 again and check the stack limit by using the ulimit -s command, which should show the new value.
Frequently Asked Questions (FAQs)
Question: What is the difference between WSL1 and WSL2?
Answer: WSL1 is the first version of the Windows Subsystem for Linux, which allows you to run Linux binaries natively on Windows. WSL1 uses a translation layer that converts Linux system calls to Windows system calls, which enables a high level of integration and performance. However, WSL1 also has some limitations, such as incomplete compatibility with some Linux applications and utilities, and lack of support for Linux kernel modules and features.
WSL2 is the second version of the Windows Subsystem for Linux, which uses a lightweight virtual machine (VM) to run a real Linux kernel on Windows. WSL2 provides full compatibility with Linux applications and utilities, and supports Linux kernel modules and features. However, WSL2 also has some drawbacks, such as increased memory usage, reduced file system performance, and reduced integration with Windows applications and services.
Question: How to switch between WSL1 and WSL2?
Answer: You can switch between WSL1 and WSL2 for any installed Linux distribution by using the wsl –set-version command. For example, to switch the Ubuntu distribution from WSL1 to WSL2, you can use the following command:
wsl --set-version Ubuntu 2
To switch it back from WSL2 to WSL1, you can use the following command:
wsl --set-version Ubuntu 1
You can check the version of any installed Linux distribution by using the wsl -l -v command, which will show the name and the version of each distribution.
Question: How to update the WSL2 kernel?
Answer: The WSL2 kernel is a component that provides the Linux kernel functionality for WSL2. Microsoft regularly updates the WSL2 kernel to include the latest features and fixes. You can update the WSL2 kernel by using the wsl –update command, which will download and install the latest kernel version. You can also check the current kernel version by using the uname -r command in WSL2, which will show the kernel release number.
Summary
In this article, we learned how to set the stack limit on WSL2 permanently using two methods: the prlimit command and the /etc/systemd/user.conf file. The stack limit is the amount of memory allocated for each thread to store temporary data. By default, the stack limit on WSL2 is 8192 KB, which may not be enough for some applications or scripts that require a large amount of stack space. By changing the stack limit, we can avoid errors such as segmentation fault or stack overflow. We also learned some basic concepts and commands related to WSL1 and WSL2, such as the difference between them, how to switch between them, and how to update the WSL2 kernel.
Disclaimer: This article is for informational purposes only and does not constitute professional advice. The author and the publisher are not liable for any damages or losses that may result from the use of the information or commands in this article. Always backup your data and test the commands in a safe environment before applying them to your system.