Appendix B. Configuration of Emulated CPUs

This appendix describes the cooperation of the system parameter related to the emulated CPUs in more
detail. The system parameter that define the emulated CPUs are:

ENGINES (Processor engine type) MAXCPU (Maximum number of CPUs) NUMCPU (Number of emulated CPUs)

B.1 General Explanations and Rules

The ENGINES parameter specifies the type of engine for each emulated processor (valid types are CP,
AP, IP or IL). MAXCPU specifies the maximum number of installed processor engines, whereas
NUMCPU defines the number of emulated processor engines that are configured online at IML time.

The ENGINES statement specifies any mixture of CPU types up to MAXCPU, the maximum number of in-
stalled processors. NUMCPU configures the processor engines in the order that they are specified on the
ENGINES statement.

NUMCPU must be less than or equal to MAXCPU. If NUMCPU is larger than MAXCPU then an error
message is issued during the processing of the Hercules configuration file. If it is less than MAXCPU then
the remaining engines can be configured online later by the operating system.

B.2 Examples

Some examples show the cooperation of these statements and the resulting configurations. In the tables
the following abbreviations and colours are used:

CPUs and status

CP CPU of type CP specified

IP CPU of type IP specified

AP CPU of type AP specified

(D) CPU got its type by default

O CPU is taken online

F CPU is taken offline

Colours

xx

Green - Resulting configuration as expected

xx

Yellow - Resulting configuration may or may be not as expected (defaults or ignored engines)

xx

Red - Resulting configuration is in error. The Hercules configuration file must be corrected.

Example 1:

ENGINES CP,CP,CP,AP,IP,IP,CP,CP

MAXCPU 8

NUMCPU 8

All CPUs are configured online with the type defined.

CPU and State

CPU 1

CPU 2

CPU 3

CPU 4

CPU 5

CPU 6

CPU 7

CPU 8

MAXCPU

1

2

3

4

5

6

7

8

NUMCPU

1

2

3

4

5

6

7

8

ENGINES

CP

CP

CP

AP

IP

IP

CP

CP

CPU t
ype

CP

CP

CP

AP

IP

IP

CP

CP

Status

O

O

O

O

O

O

O

O

Table 27: Correct CPU configuration (example 1)

Example 2:

ENGINES CP,CP,CP,AP,IP,IP,CP,CP

MAXCPU 8

NUMCPU 4

All CPUs are defined with the specified type and the first four CPUs are taken online. The rest of the
CPUs are taken offline.

CPU and State

CPU 1

CPU 2

CPU 3

CPU 4

CPU 5

CPU 6

CPU 7

CPU 8

MAXCPU

1

2

3

4

5

6

7

8

NUMCPU

1

2

3

4

---

---

---

---

ENGINES

CP

CP

CP

AP

IP

IP

CP

CP

CPU t
ype

CP

CP

CP

AP

IP

IP

CP

CP

Status

O

O

O

O

F

F

F

F

Table 28: Correct CPU configuration (example 2)

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