I am trying to improve performance on my server. I have a few processes that need low jitter (less than 10ms variance).
I have a load average of 4 maximum on an i7-920 (4 physical cores, 8 with HT). There are about 10 processes ranging from 40% to 90% of a core user mode. System usage is 3% total. Total CPU usage is 80% max.
Will setting the kernel from 100hz to 1000hz improve the jitter if tickless and high resolution timers are already set?
This page seems to indicate it still does something. https://lkml.org/lkml/2009/4/28/401
How about changing from voluntary (PREEMPT_VOLUNTARY) to preemptible (PREEMPT)?
Best Answer
If low jitter is important to you, yes, you may want to use both 1000hz and PREEMPT.
If those processes are really time-sensitive, thought, you will probably need some more realtime-oriented patches/kernels, or at least some process-level scheduling parameters, like rtprio.
Typical uses are audio servers, see for example advice from jackaudio