Red Hat Bugzilla – Bug 1462072
It shows 16 as a valid number of threads/core in RHV-M whereas the supported maximum is actually just 8
Last modified: 2017-10-13 09:42:46 EDT
Description of problem:
It shows 16 as a valid number of threads/core in RHV-M whereas the supported maximum is actually just 8.
Version-Release number of selected component (if applicable):
RHV-M register host:
Steps to Reproduce:
1.In the RHV-M GUI, configure the data center with hosts and storage， then New a vm called vm1, confirm the vm can start successfully.
2.Edit the vm1, configure 'system' option with 'Total Virtual CPUs' equals 160, 'Virtual Sockets' equals 2, 'Cores per Virtual Socket' equals 5, then the value of 'Threads per Core' will generated automatically.
The value of 'Threads per Core' will be generated as 16 automatically.
The supported maximum value of 'Threads per Core' is just 8, it can not be generated as 16.
Target release should be placed once a package build is known to fix a issue. Since this bug is not modified, the target version has been reset. Please use target milestone to plan a fix for a oVirt release.
The reason is that the maximum values are considered only when the num of CPUs changes, but not when any of the fields below.
In other words, also the coresPerSocketChanged(), threadsPerCoreChanged() and numOfSocketChanged() on the VmModelBehaviorBase will need to be made aware of the maximums.
On the other hand, when the "Total Virtual CPUs" is edited only, the values are calculated properly in a way which is preferred. The other fields are hidden under the advanced settings so I don't think it is a common issue to hit.
right, but regardless other places the max threads is just 8 and never 16. So wherever it is hardcoded to 16 we can just change to 8:)
actually it is not hardcoded but calculated and the algorithm does not handle this maximums correctly in this particular case.
But it is a low priority - moving out of 4.2 due to capacity.