Power Management for SR-IOV Adapters in Cloud Data Center
Publication Date: 2016-Mar-10
The IP.com Prior Art Database
Described is a mechanism to consolidate virtual functions under a single port/single adapter which allows one to move the port/adapter in sleep/deep sleep/free mode. This results in power savings in a data center environment.
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Power Management for SR -
In cloud data center environments, the primary customer concern is guaranteed bandwidth as per their service level agreements (SLA). The customers don't particularly care about which particular adapter or physical function are their virtual functions (VFs) coming from. This gives an opportunity to consolidate VFs under a physical function (PF) which allows Power Systems* SR-IOV firmware (PF adjunct) to shut down part of SR-IOV adapter on per-port basis.  Abstracted to the next level, VFs may be consolidated to a single adapter, thereby freeing up SR-IOV adapters with less number of provisioned VFs.
This disclosure describes the process of putting SR-IOV PF and SR-IOV adapter to sleep by consolidating virtual functions (VF) under a PF, on a different port, which may or may not be part of same SR-IOV adapter. This embodiment may be easily employed in an environment hosting multiple SR-IOV adapters of same type, wherein virtual functions are interchangeable between these adapters. The VF consolidation mechanism described below allows optimal usage of adapter and hypervisor resources. It also allows PF adjunct to partially or fully shut down SR-IOV adapter, thereby saving expensive power cycles.
This embodiment establishes a mechanism to implement power saving for SR-IOV adapters. It allows management layer user to start power saving for the CECs that the management layer is managing.  This allows PF adjunct to consolidate VFs under a destination PF while freeing up source PF having less number of active VFs. Once VF consolidation process has been able to free up a PF completely, PF can move to "sleep mode". In the sleep mode, the PF is de-provisioned and all unused hypervisor resources are reassigned back to hypervisor and all unused adapter resources are reassigned back to adapter. If all PFs under a port are in sleep mode for a predefined time interval, PF adjunct moves it to "deep sleep mode", wherein port circuitry may be shut down leading to power saving.
This process can be applied iteratively to the point wherein there are no active ports left on a given SR-IOV adapter. At this junction the entire adapter can be moved to sleep mode. Similar to the sleep mode on a per-PF basis, sleep mode for the adapter releases all adapter and hypervisor resources. At this time, the adapter is inactive and PF adjunct is just a shell code. After a pre-defined time interval, the adapter may be moved to deep sleep mode, wherein the adapter circuitry is shut down saving power cycles.
The main benefits of this invention is optimal usage of adapter and hypervisor resources by VF and PF consolidation in PF/adapter sleep mode. Another major benefit is power saving in deep sleep mode. The end user initiates power-saving workflow through management layer API. The provided power management API is flexible enough to be applied to either a single SR-IOV adapter or to all the SR-IOV adapters that this management layer insta...