Specifications

Chapter 3. Virtualization 89
Draft Document for Review May 12, 2014 12:46 pm 5102ch03.fm
number is 20 times the number of processing units that are assigned to the partition). From
the POWER Hypervisor perspective, virtual processors represent dispatching objects. The
POWER Hypervisor dispatches virtual processors to physical processors according to the
partition’s processing units entitlement. One processing unit represents one physical
processor’s processing capacity. At the end of the POWER Hypervisor’s dispatch cycle
(10 ms), all partitions receive total CPU time equal to their processing unit’s entitlement. The
logical processors are defined on top of virtual processors. So, even with a virtual processor,
the concept of a logical processor exists and the number of logical processors depends
whether the simultaneous multithreading is turned on or off.
3.4.3 Multiple shared processor pools
Multiple shared processor pools (MSPPs) is a capability that is supported on POWER8
processor-based servers. This capability allows a system administrator to create a set of
micropartitions with the purpose of controlling the processor capacity that can be consumed
from the physical shared processor pool.
Implementing MSPPs depends on a set of underlying techniques and technologies.
Figure 3-8 is an overview of the architecture of multiple shared processor pools.
Figure 3-8 Overview of the architecture of multiple shared processor pools
Micropartitions are created and then identified as members of either the default shared
processor pool
0
or a user-defined shared processor pool
n
. The virtual processors that exist
POWER Hypervisor
p1p0
Physical Shared-Processor Pool
p2 p3 p4 p5 p6 p7
Shared Processor Pool
0
Set of micro-partitions
IBM i V7.2
EC 1.6
AIX V7.1
EC 0.8
Linux
EC 0.5
vp0
vp1
vp2 vp3
vp4
AIX V7.1
EC 1.6
AIX V6.1
EC 0.8
Linux
EC 0.5
vp5
vp6
vp7
vp8 vp9
vp10
Shared Processor Pool
1
Set of micro-partitions
Unused capacity in SPP
0
is
redistributed to uncapped
micro-partitions within SPP
0
Unused capacity in SPP
1
is
redistributed to uncapped
micro-partitions within SPP
1
KEY:
EC Entitled Capacity
p Physical processor
vp Virtual processor
SPPn Shared-Processor Pool
n