Thanks, Do you think that it could explain difference?
> isolcpus disables task load balancing from the scheduler on the isolated cpu Why it is a problem? It is exactly what I want: I want to isolate CPU to be exclusive for my critical threads. What is the point to enable task load balancing here? piątek, 13 lutego 2026 o 17:38:17 UTC+1 Jean-Philippe BEMPEL napisał(a): > Hi, > > You should not use isolcpus, but use cpuset instead. > isolcpus disables task load balancing from the scheduler on the isolated > cpu, which is not the case using cpuset. > > > > On Fri, Feb 13, 2026 at 5:18 PM r r <[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/4fbbd936-a784-45b2-a58e-61a292aad704n%40googlegroups.com >> >> <https://groups.google.com/d/msgid/mechanical-sympathy/4fbbd936-a784-45b2-a58e-61a292aad704n%40googlegroups.com?utm_medium=email&utm_source=footer> >> . >> > -- 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/a8fa8484-dac5-45ba-9734-7a6a3f64aad2n%40googlegroups.com.
