chmem - Linux


chmem is a command used to modify the memory allocation of a running process. It allows users to increase or decrease the memory size allocated to a specific process. This command is particularly useful for managing memory consumption and optimizing performance.


chmem [OPTIONS] PID [-m|-b|-k|-g] NEW_VALUE


  • -m: Specifies the new memory size in megabytes.
  • -b: Specifies the new memory size in bytes.
  • -k: Specifies the new memory size in kilobytes.
  • -g: Specifies the new memory size in gigabytes.


Increase memory allocation by 100 MB:

chmem -m 100 1234

Decrease memory allocation by 512 bytes:

chmem -b 512 1234

Common Issues

  • Insufficient permissions: You may encounter permission denied errors if you do not have root access. Run the command with sudo or as the root user.
  • Invalid process ID: Ensure that the specified PID corresponds to a valid running process.


Combine with top: Monitor memory usage and modify memory allocation dynamically:

top -c | awk '/PID/{print $1}' | xargs chmem -m 200

Related Commands

  • free: Displays system memory usage.
  • ps: Lists running processes and their memory usage.