> From: Stephen Hemminger [mailto:step...@networkplumber.org] > Sent: Thursday, 26 October 2023 18.32 > > On Thu, 26 Oct 2023 09:33:42 +0200 > Morten Brørup <m...@smartsharesystems.com> wrote: > > > > From: Stephen Hemminger [mailto:step...@networkplumber.org] > > > Sent: Wednesday, 25 October 2023 23.33 > > > > > > On Wed, 25 Oct 2023 19:54:06 +0200 > > > Morten Brørup <m...@smartsharesystems.com> wrote:
[...] > > > > Someone might build a kernel with options to keep non-dataplane > threads off > > > some dedicated CPU cores, so they can be used for guaranteed low- > latency > > > dataplane threads. We do. We don't use real-time priority, though. > > > > > > This is really, hard to do. > > > > As my kids would say: This is really, really, really, really, really > hard to do! > > > > We have not been able to find an authoritative source of > documentation describing how to do it. :-( [...] > One benefit of doing real-time thread is that kernel will be more > precise in > any calls to sleep. If you do small sleep in normal thread, the kernel > will round > up the timer to try and avoid reprogramming timer chip and to save > power (less wakeups from idle). > With RT thread it will do "you wanted 21us, ok for you will do 21us" So we don't need PR_SET_TIMERSLACK with RT threads? > > The project that was originally Vyatta, has a script that tries to > isolate interrupts etc. > I started it but they have worked on it since then. > > https://github.com/danos/vyatta-cpu-shield > > It adjust kernel workers, softirq, cgroups etc This script looks very interesting. Thank you, Stephen!
