RHEL-RT GeneralSystemTuningHowto

From RHEL-RT

Contents 1 General System Tuning 2 Background Info on Tuning 3 Recommended Tuning 3.1 Try these first 3.2 Later try these 4 Future content

General System Tuning

This section highlights the general system tuning tips which typically are most beneficial in improving determinism. These tuning tips are equally applicable to standard RHEL5 as well as MRG Realtime. It is recommended that these tuning tips be done first, before considering realtime specific tunings. By doing so, you will be better positioned to see the benefits of the realtime kernel.

Background Info on Tuning

This first section provides some background information on how to modify tuning parameters.

• Setting persistent tuning parameters - RHEL-RT PersistentParamsHowto

Recommended Tuning

There are a variety of system tunings to try. We have tried to separate out the ones to try first as they typically yield the most benefit.

Try these first

When we do our performance benchnarks and roll up our sleeves for system tuning, these are usually the first settings we reach for.

• Interrupt and Process Binding - binding interrupts and user applications to specific CPUs: RHEL-RT AffinityHowto
• Filesystem determinism tips - RHEL-RT FilesystemDeterminismHowto

Later try these

These tunings are more for fine-tuning.

• gettimeofday(2) speedup - RHEL-RT VDSOHowto
• Don't run extra stuff - RHEL-RT DontRunExtraStuffHowto
• Swapping is non-deterministic & OOM killer tunables - RHEL-RT SwappingNonDeterminismHowto
• Network determinism tips - RHEL-RT NetworkDeterminismHowto
• Syslog tuning tips - RHEL-RT SyslogTuningHowto

Future content

This section highlights additional topics we intend to cover, which are related to realtime system tuning:

tbd