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1*1031c584SApple OSS Distributions<h2>memory_object_perf_info</h2>
2*1031c584SApple OSS Distributions<hr>
3*1031c584SApple OSS Distributions<p>
4*1031c584SApple OSS Distributions<strong>Structure</strong> - Specifies a memory object's attributes with respect to performance.
5*1031c584SApple OSS Distributions<h3>SYNOPSIS</h3>
6*1031c584SApple OSS Distributions<pre>
7*1031c584SApple OSS Distributions<strong>struct  memory_object_perf_info</strong>
8*1031c584SApple OSS Distributions<strong>{</strong>
9*1031c584SApple OSS Distributions        <strong>vm_offset_t</strong>      <var>cluster_size</var><strong>;</strong>
10*1031c584SApple OSS Distributions        <strong>boolean_t</strong>    <var>may_cache_object</var><strong>;</strong>
11*1031c584SApple OSS Distributions<strong>};</strong>
12*1031c584SApple OSS Distributions
13*1031c584SApple OSS Distributions<strong>typedef struct memory_object_perf_info* memory_object_perf_info_t;</strong>
14*1031c584SApple OSS Distributions</pre>
15*1031c584SApple OSS Distributions<h3>FIELDS</h3>
16*1031c584SApple OSS Distributions<dl>
17*1031c584SApple OSS Distributions<dt> <var>cluster_size</var>
18*1031c584SApple OSS Distributions<dd>
19*1031c584SApple OSS DistributionsPreferred cluster size (in bytes) for the memory object.  This helps to
20*1031c584SApple OSS Distributionsdetermine how many pages are transferred in individual data request
21*1031c584SApple OSS Distributionsand return messages.
22*1031c584SApple OSS Distributions<p>
23*1031c584SApple OSS Distributions<dt> <var>may_cache_object</var>
24*1031c584SApple OSS Distributions<dd>
25*1031c584SApple OSS DistributionsCache indicator.  If true, the kernel can cache data associated with the
26*1031c584SApple OSS Distributionsmemory object (keep the memory object active) even if no virtual
27*1031c584SApple OSS Distributionsmemory references to it remain.
28*1031c584SApple OSS Distributions</dl>
29*1031c584SApple OSS Distributions<h3>DESCRIPTION</h3>
30*1031c584SApple OSS Distributions<p>
31*1031c584SApple OSS DistributionsThe <strong>memory_object_perf_info</strong> structure
32*1031c584SApple OSS Distributionsdefines a memory object's character with respect to performance.
33*1031c584SApple OSS Distributions<h3>NOTES</h3>
34*1031c584SApple OSS Distributions<p>
35*1031c584SApple OSS DistributionsSharing cached data among all the clients of a memory object can have a major
36*1031c584SApple OSS Distributionsimpact on performance, especially if it can be extended across successive, as
37*1031c584SApple OSS Distributionswell as concurrent, uses.  For example, the memory objects that represent
38*1031c584SApple OSS Distributionsprogram images can be used regularly by different programs.
39*1031c584SApple OSS DistributionsBy retaining the data
40*1031c584SApple OSS Distributionsfor these memory objects in cache, the number of secondary storage accesses
41*1031c584SApple OSS Distributionscan be reduced significantly.
42*1031c584SApple OSS Distributions<h3>RELATED INFORMATION</h3>
43*1031c584SApple OSS Distributions<p>
44*1031c584SApple OSS DistributionsFunctions:
45*1031c584SApple OSS Distributions<a href="MO_get_attributes.html"><strong>memory_object_get_attributes</strong></a>,
46*1031c584SApple OSS Distributions<a href="MO_change_attributes.html"><strong>memory_object_change_attributes</strong></a>,
47*1031c584SApple OSS Distributions<a href="vm_region.html"><strong>vm_region</strong></a>,
48*1031c584SApple OSS Distributions<a href="memory_object_synchronize.html"><strong>memory_object_synchronize</strong></a>,
49*1031c584SApple OSS Distributions<a href="VSD_memory_manager.html"><strong>vm_set_default_memory_manager</strong></a>,
50*1031c584SApple OSS Distributions<a href="vm_msync.html"><strong>vm_msync</strong></a>.
51*1031c584SApple OSS Distributions<p>
52*1031c584SApple OSS DistributionsStructures:
53*1031c584SApple OSS Distributions<a href="memory_object_attr_info.html"><strong>memory_object_attr_info</strong></a>.
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