Red Hat Enterprise Linux for Real Time 7

Tuning Guide

Advanced tuning procedures for Red Hat Enterprise Linux for Real Time

Maxim Svistunov

Red Hat Customer Content Services

Radek Bíba

Red Hat Customer Content Services

David Ryan

Red Hat Customer Content Services

Cheryn Tan

Red Hat Customer Content Services

Lana Brindley

Red Hat Customer Content Services

Alison Young

Red Hat Customer Content Services

Abstract

This book contains advanced tuning procedures for Red Hat Enterprise Linux for Real Time. For installation instructions, see the Red Hat Enterprise Linux for Real Time Installation Guide.
Preface
1. Before You Start Tuning Your Red Hat Enterprise Linux for Real Time System
2. General System Tuning
2.1. Using the Tuna Interface
2.2. Setting Persistent Tuning Parameters
2.3. Setting BIOS Parameters
2.4. Interrupt and Process Binding
2.5. File System Determinism Tips
2.6. Using Hardware Clocks for System Timestamping
2.7. Avoid Running Extra Applications
2.8. Swapping and Out of Memory Tips
2.9. Network Determinism Tips
2.10. syslog Tuning Tips
2.11. The PC Card Daemon
2.12. Reduce TCP Performance Spikes
2.13. System Partitioning
3. Realtime-Specific Tuning
3.1. Setting Scheduler Priorities
3.2. Using kdump and kexec with the Red Hat Enterprise Linux for Real Time Kernel
3.3. TSC Timer Synchronization on Opteron CPUs
3.4. Infiniband
3.5. RoCEE and High Performance Networking
3.6. Non-Uniform Memory Access
3.7. Reducing the TCP Delayed ACK Timeout
3.8. Using debugfs
3.9. Using the ftrace Utility for Tracing Latencies
3.10. Latency Tracing Using trace-cmd
3.11. Using sched_nr_migrate to Limit SCHED_OTHER Task Migration.
3.12. Real Time Throttling
3.13. Isolating CPUs Using tuned-profiles-realtime
3.14. Offloading RCU Callbacks
4. Application Tuning and Deployment
4.1. Signal Processing in Realtime Applications
4.2. Using sched_yield and Other Synchronization Mechanisms
4.3. Mutex Options
4.4. TCP_NODELAY and Small Buffer Writes
4.5. Setting Realtime Scheduler Priorities
4.6. Loading Dynamic Libraries
4.7. Using _COARSE POSIX Clocks for Application Timestamping
4.8. About Perf
5. More Information
5.1. Reporting Bugs
A. Event Tracing
B. Detailed Description of Ftrace
C. Revision History