1<h2>memory_object_perf_info</h2>
2<hr>
3<p>
4<strong>Structure</strong> - Specifies a memory object's attributes with respect to performance.
5<h3>SYNOPSIS</h3>
6<pre>
7<strong>struct  memory_object_perf_info</strong>
8<strong>{</strong>
9        <strong>vm_offset_t</strong>      <var>cluster_size</var><strong>;</strong>
10        <strong>boolean_t</strong>    <var>may_cache_object</var><strong>;</strong>
11<strong>};</strong>
12
13<strong>typedef struct memory_object_perf_info* memory_object_perf_info_t;</strong>
14</pre>
15<h3>FIELDS</h3>
16<dl>
17<dt> <var>cluster_size</var>
18<dd>
19Preferred cluster size (in bytes) for the memory object.  This helps to 
20determine how many pages are transferred in individual data request 
21and return messages.
22<p>
23<dt> <var>may_cache_object</var>
24<dd>
25Cache indicator.  If true, the kernel can cache data associated with the 
26memory object (keep the memory object active) even if no virtual 
27memory references to it remain.
28</dl>
29<h3>DESCRIPTION</h3>
30<p>
31The <strong>memory_object_perf_info</strong> structure
32defines a memory object's character with respect to performance.
33<h3>NOTES</h3>
34<p>
35Sharing cached data among all the clients of a memory object can have a major 
36impact on performance, especially if it can be extended across successive, as 
37well as concurrent, uses.  For example, the memory objects that represent
38program images can be used regularly by different programs. 
39By retaining the data 
40for these memory objects in cache, the number of secondary storage accesses 
41can be reduced significantly.
42<h3>RELATED INFORMATION</h3>
43<p>
44Functions:
45<a href="MO_get_attributes.html"><strong>memory_object_get_attributes</strong></a>,
46<a href="MO_change_attributes.html"><strong>memory_object_change_attributes</strong></a>,
47<a href="vm_region.html"><strong>vm_region</strong></a>,
48<a href="memory_object_synchronize.html"><strong>memory_object_synchronize</strong></a>,
49<a href="VSD_memory_manager.html"><strong>vm_set_default_memory_manager</strong></a>,
50<a href="vm_msync.html"><strong>vm_msync</strong></a>.
51<p>
52Structures:
53<a href="memory_object_attr_info.html"><strong>memory_object_attr_info</strong></a>.
54