MPSYS parameter: Difference between revisions

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<dd>All
<dd>All
<dt>Introduced
<dt>Introduced
<dd><var class="product">Model 204 V6.1</var> or earlier
<dd><var class="product">Model 204 V5.1</var>  
</dl>
</dl>


==Description==
==Description==
<p>
<p>
This parameter indicates a system-wide MP/204 processing option and applies only to z/OS.</p>
This parameter indicates a system-wide <var>[[Performance_monitoring_and_tuning#Multiprocessing_.28MP.2F204.29|MP/204]]</var> processing option and applies only to z/OS.</p>
<p>This parameter is ignored when Model 204 is not running with MP/204 enabled.</p>
<table>
<table>
<tr class="head"><th>Setting </th><th>Meaning </th><th>Purpose</th></tr>
<tr class="head"><th>Setting </th><th>Meaning </th><th>Purpose</th></tr>
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<tr><th><var>X'02'</var></th>
<tr><th><var>X'02'</var></th>
<td>A thread should stay on the main task after getting a critical file resource.</td>
<td>A thread should stay on the maintask after getting a critical file resource.</td>
<td>To improve performance at an MP/204 site that is encountering a lot of task switching (a high STDEQ system statistic) and a lot of critical file resource conflicts. </td></tr>
<td>To improve performance at an MP/204 site that is encountering a lot of task switching (a high STDEQ system statistic) and a lot of critical file resource conflicts. </td></tr>
</table>
</table>

Latest revision as of 16:36, 30 March 2017

MP/204 system flags

Summary

Default value
0
Parameter type
System
Where set
On User 0's parameter line or reset by system manager
Related products
All
Introduced
Model 204 V5.1

Description

This parameter indicates a system-wide MP/204 processing option and applies only to z/OS.

This parameter is ignored when Model 204 is not running with MP/204 enabled.

Setting Meaning Purpose
X'01' A thread should continue spinning on an MP lock even if it appears that the task holding the lock cannot be dispatched. In many situations, continuing to spin provides better performance than doing an operating system wait for the lock to free up.
X'02' A thread should stay on the maintask after getting a critical file resource. To improve performance at an MP/204 site that is encountering a lot of task switching (a high STDEQ system statistic) and a lot of critical file resource conflicts.