renice

Overview

The renice command alters the scheduling priority of running processes. It allows you to change the niceness (priority) of one or more running processes.

Syntax

renice priority [[-p] pid...] [[-g] pgrp...] [[-u] user...]

Common Options

Option Description
-n Priority value
-p Process IDs
-g Process groups
-u Users
-h Show help
-v Verbose mode
--version Show version

Priority Values

Value Priority
-20 Highest
-10 High
0 Normal
10 Low
19 Lowest

Key Use Cases

  1. Adjust priority
  2. Resource control
  3. Performance tuning
  4. System optimization
  5. Process management

Examples with Explanations

Example 1: Process Priority

renice +5 -p 1234

Lower process priority

Example 2: User Processes

renice +10 -u username

Adjust user priorities

Example 3: Process Group

renice -5 -g 100

Higher group priority

Common Usage Patterns

  1. Single process:

    renice -n 10 -p PID

  2. Multiple PIDs:

    renice 5 -p PID1 PID2

  3. User processes:

    renice -n 15 -u user

Priority Management

  1. Current priority
  2. Adjustment limits
  3. User restrictions
  4. System impact
  5. Process groups

Additional Resources

Best Practices

  1. Check limits
  2. Monitor impact
  3. Document changes
  4. Test settings
  5. Regular review

Security Considerations

  1. User permissions
  2. System resources
  3. Priority limits
  4. Process control
  5. Resource abuse

Troubleshooting

  1. Permission denied
  2. Priority limits
  3. System load
  4. Process behavior
  5. Resource conflicts

System Impact

  1. CPU scheduling
  2. Process priority
  3. System load
  4. User experience
  5. Resource sharing