Memory Allocator with Cgroup Management

Overview

memory_allocator is a program that spawns a child process, assigns it to a cgroup with a memory limit, and makes the child process allocate a specified amount of memory. The process then sleeps for a given duration before exiting. This program demonstrates cgroup-based memory management in Linux.

Features

• Creates a child process and assigns it to a dedicated cgroup.
• Enforces a memory limit on the child process.
• Allows the child process to allocate a user-defined amount of memory.
• Supports a configurable sleep duration before exiting.
• Handles cleanup and signal interruptions gracefully.

Requirements

• Linux system with cgroup v2 enabled.
• Root privileges (or appropriate cgroup permissions).

Usage

./memory_allocator <memory_in_MiB> <cgroup_mem_limit_in_MiB> <sleep_time_in_seconds>

Arguments

• <memory_in_MiB>: Amount of memory (in MiB) that the child process should allocate.
• <cgroup_mem_limit_in_MiB>: Memory limit (in MiB) for the cgroup.
• <sleep_time_in_seconds>: Duration (in seconds) the child process should sleep before exiting.

Example

sudo ./memory_allocator 100 200 10

This command:

• Spawns a child process that allocates 100 MiB of memory.
• Places the child in a cgroup with a 200 MiB memory limit.
• Keeps the child process running for 10 seconds before cleanup.

Signal Handling

• The program handles SIGINT and SIGTERM.
• On receiving a signal, it frees allocated memory and sleeps before exiting.

Implementation Details

• Parses the current cgroup path from /proc/self/cgroup.
• Moves the parent process to the controller cgroup.
• Creates a cgroup for the child process with a specified memory limit.
• Enables memory and pids controllers for the child process cgroup.
• Moves the child process to the new cgroup and enforces limits.
• Waits for the child to terminate before the parent exits.

License

This project is released under the MIT License.