Installing and Managing HP-UX Virtual Partitions (includes A.04.02)

CPU, Memory, and IO Resources (A.03.xx)
CPU: Dual-Core
Chapter 7
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CPU: Dual-Core
With the PA-8800s and other dual-cores, there are two CPUs per socket. (On a cell board with four sockets,
this allows 8 CPUs per cell board.) The CPUs that share the socket are called sibling CPUs.
Splitting sibling CPUs across virtual partition refers to assigning one sibling CPU to one partition and
assigning the other sibling CPU to a different virtual partition. No noticeable performance degradation has
been seen when splitting sibling CPUs. Due to items such as the larger L2 cache size, there actually can be a
small performance boost if the siblings are split such that one of the virtual partitions has no workload. If you
require consistently predictable performance, configure the virtual partitions consistently; in other words,
whether you split siblings or keep them together, always do the same thing.
Determining if the system has Dual-Core CPUs
You can see the sibling and virtual partition assignment using vparstatus -d. If you do not have a dual-core
system, the output will show dashes (-) for the sibling and assignment information:
# vparstatus -d
CPU Cell Config Sibling Information
path CPU HPA ID Status Assigned to Path /vPar name
===== ================== ==== ====== ================== =======================
0.10 0xfffffffffc078000 0 E vpuma02 - -
0.11 0xfffffffffc07a000 0 E vpuma01 - -
0.12 0xfffffffffc07c000 0 E vpuma04 - -
0.13 0xfffffffffc07e000 0 E - - -
...
When you do have dual-core system, the vparstatus -d output will look similar to the following:
# vparstatus -d
CPU Cell Config Sibling Information
path CPU HPA ID Status Assigned to Path /vPar name
===== ================== ==== ====== ================== =======================
0.10 0xfffffffffc070000 0 E vpkeira1 0.11 vpkeira3
0.11 0xfffffffffc071000 0 E vpkeira3 0.10 vpkeira1
0.12 0xfffffffffc074000 0 E - 0.13 vpkeira4
0.13 0xfffffffffc075000 0 E vpkeira4 0.12 -
0.14 0xfffffffffc078000 0 E - 0.15 -
0.15 0xfffffffffc079000 0 E - 0.14 -
...
You can also use the parstatus command or parmgr to determine if you are running dual-cores. If the
maximum number of CPUs per cell is 8, then you are running dual-cores:
# parstatus -c 0
[Cell]
CPU Memory Use
OK/ ( GB) Core On
Hardware Actual Deconf/ OK/ Cell Next Par
Location Usage Max Deconf Connected To Capable Boot Num
========== ============ ======= ========= =================== ======= ==== ===
cab0,cell0 active core 8/0/8 2.0/ 0.0 cab0,bay0,chassis0 yes yes 0