Can you please add more details? How many sockets/cores? What hardware brand? What distro/OS version? Is it a regular vs real time kernel? What does pidstat show that your app is doing? Specifically how many cores is this app using? Are there other apps running on the same host? Are you doing anything with cgroups? Are you using a tuned profile?
Note that some of the low latency OS features depend upon matching kernel settings with BIOS settings - which is why I ask which hardware vendor? Correct power savings behavior depends on having correct BIOS settings. On Friday, February 13, 2026 at 11:18:49 AM UTC-5 [email protected] wrote: > Hi, > > let's look at the example: > > The system is running with the following kernel parameters: > > isolcpus=10, nohz_full=10, nohz=on, idle=poll, intel_pstate=disable. > > We have a thread *T* that uses Thread.onSpinWait() while polling a > lock-free shared queue. In this context, the *task interval* refers to > the time elapsed between adding consecutive tasks to the queue. > > When thread *T* is pinned to CPU #10 and the task interval is set to 1ms, > the average task execution time is *100 µs*. However, when the task > interval is increased to 40ms on the same pinned core, the average > execution time significantly degrades to *250 µs*. > > In contrast, when thread *T* is unpinned, the performance remains much > more consistent. At a 1ms task interval, the average execution time is *110 > µs*, and it only slightly increases to *120 µs* when the interval is > extended to 40ms. > -- You received this message because you are subscribed to the Google Groups "mechanical-sympathy" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To view this discussion, visit https://groups.google.com/d/msgid/mechanical-sympathy/a4ed80d2-8d28-4667-a425-a418b03bb1b3n%40googlegroups.com.
