IBM Power 780 - Page 162

148 IBM Power 770 and 780 (9117-MMD, 9179-MHD) Technical Overview and Introduction
Identical pages within the same or different LPARs each require their own unique physical
memory page, consuming space with repeated information.
Figure 3-13 Active Memory Sharing shared memory pool without Active Memory Deduplication
enabled
Active Memory Deduplication allows the hypervisor to dynamically map identical partition
memory pages to a single physical memory page within a shared memory pool. This way
enables a better utilization of the Active Memory Sharing shared memory pool, increasing the
system’s overall performance by avoiding paging. Deduplication can cause the hardware to
incur fewer cache misses, which also leads to improved performance.
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Without
Active Memory
Deduplication
Mappings
AMS shared memory pool
LPAR1
Logical Memory
LPAR2
Logical Memory
LPAR3
Logical Memory
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Duplicate pages
Unique pages
KEY: