On 08.07.2025 19:40, Stefano Stabellini wrote: > On Tue, 8 Jul 2025, Jan Beulich wrote: >> On 08.07.2025 02:07, Stefano Stabellini wrote: >>> On real time configuration with the null scheduler, we shouldn't >>> interrupt the guest execution unless strictly necessary: the guest could >>> be a real time guest (e.g. FreeRTOS) and interrupting its execution >>> could lead to a missed deadline. >>> >>> The principal source of interruptions is IPIs. Remove the unnecessary >>> IPI on all physical CPUs to sync the TSC when the TSC is known to be >>> reliable. >> >> If it had been truly unnecessary for all the time, I'm sure someone would >> have suggested to get rid of the overhead. > > I am not so sure someone else would have suggested it given that Xen on > x86 has been mostly used on the datacenter where real-time is not a > requirement.
What I mean to indicate is that we're generally always on the hunt of unnecessary overhead that can be eliminated. Jan
