#opnfv-meeting: weekly tech discuss

Meeting summary

1. Performance Tuning through optimal bios settings (efoley, 13:07:12)
   1. iLO provides additional metrics that give information about the workloads, which may differ from the corresponding metrics given by the operating system (efoley, 13:11:11)
   2. This gives enhanced capabilities for workload matching between system capabilities and workload requirements (efoley, 13:12:05)
   3. There are multiple workload profiles available, and will tune the system to optimise for e.g. latency, throughput, maximum frequency, etc (efoley, 13:14:57)
   4. Custom workload profiles can also be defined for user that want to set specific BIOS config options (efoley, 13:16:26)
   5. Opportunistic CPU frequency shifting can introduce latency and non-determinism to the workloads, this can be problematic for workloads that are latency sensitive and rely on deterministic performance. These delays can destroy the benefit of the increased performance. (efoley, 13:21:01)
   6. There are different features that provide opportunistic performance boosts and power savings, by modifying the processor frequency (p-states and power management, turbo boost, C-states, power and thermal events, Advanced Vector Extensons), these all provide sources of jitter (and latency) in the system. (efoley, 13:29:00)
   7. Changes to CPU frequency requires stopping the core for a short time, typically 10-15us. (efoley, 13:30:05)
   8. In some instances, using the intel_idle driver means that the C-state reporting and API options are ignored. This driver needs to be disabled for optimal jitter reduction (efoley, 13:35:00)
   9. Processor jitter control can be used to improve performance for workloads that are traditionally sensitive to latency (efoley, 13:37:07)
   10. Processor jitter control sets a base frequency, and causes frequency changes to below this to be ignored (efoley, 13:40:12)
   11. Using processor jitter control, a higher performance can be seen with a lower CPU frequency (pres has graphs available) (efoley, 13:45:04)
   12. odim.io (Open Distributed Infrastricture Management) is an initiative to collaborate with multiple vendors. (efoley, 13:59:02)

Action items

1. (none)

People present (lines said)

1. efoley (15)
2. collab-meetbot (3)