On Wed, Mar 24, 2010 at 7:49 AM, Rob <[email protected]> wrote: > Maarten Wiltink <[email protected]> wrote: >> Do VMs still have problems responding to timer ticks when there are >> enough cores to go around? > > If anything, the problems tend to get worse when you have many cores.
Multi-core VMs present a significant challenge in a virtualized environment, as the cores themselves can actually run at slightly different times rates, and may be de-scheduled by the hypervisor at different times. And this "disparity between cores" has actually become even greater in the most recent VMware 4: http://www.vmware.com/files/pdf/perf-vsphere-cpu_scheduler.pdf Great for aggregate application throughput, but not so good for NTP. I wonder if setting affinity for NTP to a single virtual core would help. -- RPM _______________________________________________ questions mailing list [email protected] http://lists.ntp.org/listinfo/questions
