Average task execution time is less interesting that seeing raw latency data - what does this app do? Is it listening to market data, customer orders, doing rescheduled work? Are you using specialized (SolarFlare/Mellanox NICs? 100 µs is a long time with Skylake and newer hardware.
On Friday, February 13, 2026 at 3:26:04 PM UTC-5 [email protected] wrote: > No. Actually, after some retests my observation is that it happens > regardless the thread is pinned or not. > So, > > 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*. If T is not pinned, > the result is same. > > > piątek, 13 lutego 2026 o 18:39:03 UTC+1 Mark E. Dawson, Jr. napisał(a): > >> Do you have a baseline for how your isolated core should perform using a >> tool like 'osnoise'? >> >> On Friday, February 13, 2026 at 10:18:49 AM UTC-6 [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/355a5cdc-07ec-4f02-b752-9ccefb3e44c7n%40googlegroups.com.
