Description of problem: Real time guest requires <features>pmu state='off'. For backward compatibility, it might be better to add an explicit hw:pmu_state=on|off extraspec/image metadata key. Version-Release number of selected component (if applicable): OSP13
The PMU emulation in KVM increases wakeup latency by some microseconds when running cyclictest, so we need to be able to turn it off.
this is a valid request but it will require a spec upstream and to write it we will need to have a performance assessment of the impact of enabling or not enabling it on realtime workloads. can you link to any public assessment that can be used to justify this upstream. this may be back portable as it should not involve any api change but we will not know that until the feature is implemented. we are significantly past the window for new features for OSP 15 so i am provisionally targeting this for OSP 16.
This has now merged on master so setting to post.
Some whitebox tests have merged for this: https://review.opendev.org/#/c/695551/
Since the problem described in this bug report should be resolved in a recent advisory, it has been closed with a resolution of ERRATA. For information on the advisory, and where to find the updated files, follow the link below. If the solution does not work for you, open a new bug report. https://access.redhat.com/errata/RHEA-2020:0283