XMEMOPT parameter: Difference between revisions
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<dl> | <dl> | ||
<dt>Default value | <dt>Default value | ||
<dd>2 if M204XSVC is linked into the nucleus; 0 if M204XSVC is not linked | <dd>2, if M204XSVC is linked into the nucleus; 0, if M204XSVC is not linked | ||
<dt>Parameter type | <dt>Parameter type | ||
<dd>System | <dd>System | ||
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<tr><th><var>X'01'</var></th> | <tr><th><var>X'01'</var></th> | ||
<td>Invokes Timer PC. </td></tr> | <td>Invokes Timer PC. | ||
<p class="note"><b>Note:</b> As described in the [[Performance monitoring and tuning#Timer PC|Timer PC]] section, this bit is automatically turned off as of version 7.4 of Model 204 if your system supports the ECTG instruction. </p></td></tr> | |||
<tr><th><var>X'00'</var></th> | <tr><th><var>X'00'</var></th> | ||
Revision as of 20:56, 2 September 2016
Cross-memory PC options
Summary
- Default value
- 2, if M204XSVC is linked into the nucleus; 0, if M204XSVC is not linked
- Parameter type
- System
- Where set
- On User 0's parameter line
- Related products
- All
- Introduced
- Model 204 V6.1 or earlier
Description
This parameter sets the Model 204 cross-memory services options that can be invoked during execution of Model 204.
This parameter applies only to z/OS.
The XMEMSVC parameter is used with any of the nonzero settings.
Valid settings of XMEMOPT are:
| Setting | Meaning |
|---|---|
| X'80' | Activates CRAM-XDM. |
| X'20' | Use SUSPEND/RESUME instead of WAIT/POST for communication between Model 204 real subtasks. This option may reduce operating system overhead slightly. |
| X'04' | Forces initialization of cross-memory environment. |
| X'03' | Invokes both Timer PC and IOS Branch Entry. |
| X'02' | Invokes IOS Branch Entry (recommended for z/OS).
|
| X'01' | Invokes Timer PC.
Note: As described in the Timer PC section, this bit is automatically turned off as of version 7.4 of Model 204 if your system supports the ECTG instruction. |
| X'00' | Disables Timer PC and IOS Branch Entry. |
Note: VIO is incompatible with IOSBE and EXCPVR.