Description of problem: The node labeller marks the nodes with: * their exact TSC frequency * the lowest TSC frequency in the cluster IF they support tsc-scalable Hypothetical example, on a cluster where the lowest frequency is X NAME TSC-FREQUENCY TSC-SCALABLE TSC-FREQUENCY-X TSC-FREQUENCY-Y node1 X true true node2 Y true true true node3 Y false true However, TSC scaling may not be an exact number in many CPU models, leaving some possible variation. See this, same CPU on 2 different systems (or even same system and 2 reboots), there is a 1 Mhz difference that can show up between reboots or systems with same CPU [ 0.000000] tsc: Fast TSC calibration using PIT [ 0.000000] tsc: Detected 2297.345 MHz processor [ 4.127014] tsc: Refined TSC clocksource calibration: 2297.339 MHz [ 0.000000] tsc: Fast TSC calibration using PIT [ 0.000000] tsc: Detected 2297.449 MHz processor [ 4.063010] tsc: Refined TSC clocksource calibration: 2297.338 MHz If we do X = 2297.338 Y = 2297.339 Then a Windows VM with re-enlightenment will never run on node3, because its missing TSC-FREQUENCY-X label by 1MHZ off. The logic will consider this an heterogeneous cluster, but its not. The system should be able to schedule VMs on any of those 3 nodes, regardless of TSC-SCALABLE or not. Because these are essentially the same frequency. Lower layers accept this variance, BZ1839095 Version-Release number of selected component (if applicable): 4.12.10 How reproducible: Always Steps to Reproduce: 1. Use systems with TSC-SCALABLE = false and same CPUs, reboot until different frequencies. Actual results: * VMs fail to schedule on nodes with same CPU Expected results: * VMs scheduled
I'm closing this as it appears to be a complete duplicate of https://bugzilla.redhat.com/show_bug.cgi?id=2184860 Please feel free to re-open if I've misunderstood or if you intentionally opened two. (and please clarify if so). *** This bug has been marked as a duplicate of bug 2184860 ***
(In reply to sgott from comment #2) > I'm closing this as it appears to be a complete duplicate of > https://bugzilla.redhat.com/show_bug.cgi?id=2184860 > > Please feel free to re-open if I've misunderstood or if you intentionally > opened two. (and please clarify if so). > > *** This bug has been marked as a duplicate of bug 2184860 *** No you are right, its a duplicate. Not sure why it does this sometimes. Click submit once in a 100 times there will be 2 bugs with sequential number, had it before.