XMEMOPT parameter: Difference between revisions
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==Description== | ==Description== | ||
<p> | <p> | ||
<p>This parameter applies only to z/OS.</p> | This parameter sets the <var class="product">Model 204</var> cross-memory services options that can be invoked during execution of <var class="product">Model 204</var>. </p> | ||
<p>The XMEMSVC parameter is used with any of the nonzero settings. </p> | <p> | ||
<p>Valid settings of XMEMOPT are: | This parameter applies only to z/OS.</p> | ||
<p> | |||
The <var>[[XMEMSVC parameter|XMEMSVC]]</var> parameter is used with any of the nonzero settings. </p> | |||
<p>Valid settings of <var>XMEMOPT</var> are: </p> | |||
<table> | <table> | ||
<tr><th>Setting</th><th>Meaning</th></tr> | <tr class="head"><th>Setting</th><th>Meaning</th></tr> | ||
<tr><th align="right"><var>X'80'</var></th><td>Activates CRAM-XDM.</td></tr> | <tr><th align="right"><var>X'80'</var></th><td>Activates CRAM-XDM.</td></tr> | ||
<tr><th align="right"><var>X'20'</var></th><td>Use SUSPEND / RESUME instead of WAIT / POST for communication between <var class="product">Model 204</var> real subtasks. This option may reduce operating system overhead slightly.</td></tr> | |||
<tr><th | <tr><th align="right"><var>X'20'</var></th><td>Use SUSPEND/RESUME instead of WAIT/POST for communication between <var class="product">Model 204</var> real subtasks. This option may reduce operating system overhead slightly.</td></tr> | ||
<tr><th | |||
<tr><th | <tr><th><var>X'04'</var></th> | ||
<tr><th | <td>Forces initialization of cross-memory environment. </td></tr> | ||
<tr><th | |||
<tr><th><var>X'03'</var></th> | |||
<td>Invokes both TIMER PC and IOS BRANCH ENTRY.</td></tr> | |||
<tr><th><var>X'02'</var></th> | |||
<td>Invokes IOS BRANCH ENTRY (recommended for z/OS). | |||
<p> | |||
As of Model 204 version 7.6, the X'02' setting is required for [[Performance monitoring and tuning#Offloading Model 204 work to zIIP processors|zIIP processing]].</p></td></tr> | |||
<tr><th><var>X'01'</var></th> | |||
<td>Invokes TIMER PC</td></tr> | |||
<tr><th><var>X'00'</var></th> | |||
<td>Disables TIMER PC and IOS BRANCH ENTRY.</td></tr> | |||
</table> | </table> | ||
<p class="note"><b>Note:</b> VIO is incompatible with IOSBE and EXCPVR.</p> | <p class="note"><b>Note:</b> VIO is incompatible with IOSBE and EXCPVR.</p> | ||
[[Category:System parameters]] | [[Category:System parameters]] | ||
[[Category:Parameters]] | [[Category:Parameters]] | ||
Revision as of 19:44, 15 April 2016
Cross-memory PC options
Summary
- Default value
- 4 if M204XSVC is linked into the nucleus
- 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).
As of Model 204 version 7.6, the X'02' setting is required for zIIP processing. |
| X'01' | Invokes TIMER PC |
| X'00' | Disables TIMER PC and IOS BRANCH ENTRY. |
Note: VIO is incompatible with IOSBE and EXCPVR.