Re:Low Latency Optimization: Understanding Pages (Part 1)
by zozbot234 on Tuesday November 29, 2022 @07:12AM
(#33786554)
> If you're on PREEMPT_RT and give your critical thread highest prio, be prepared for some serious OS-level lock-ups.
PREEMPT_RT includes priority inheritance, specifically to avoid this scenario. So your app should indeed be favored if you tune accordingly. What you also seem to be saying is that using PREEMPT_RT may lead to lower throughput, but that's not the same thing as latency.
Re:Low Latency Optimization: Understanding Pages (Part 1)
by bitcharmer on Tuesday November 29, 2022 @09:40AM
(#33788140)
Priority inheritance is a fundamental feature of all scheduling domains in the kernel and has nothing to do with the problem I described.
Also, PREEMPT_RT is the worst option for low latency because it's about execution time guarantees and not speed specifically. If you're on PREEMPT_RT and give your critical thread highest prio, be prepared for some serious OS-level lock-ups.