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1*5e3eaea3SApple OSS Distributions<h2>memory_object_perf_info</h2>
2*5e3eaea3SApple OSS Distributions<hr>
3*5e3eaea3SApple OSS Distributions<p>
4*5e3eaea3SApple OSS Distributions<strong>Structure</strong> - Specifies a memory object's attributes with respect to performance.
5*5e3eaea3SApple OSS Distributions<h3>SYNOPSIS</h3>
6*5e3eaea3SApple OSS Distributions<pre>
7*5e3eaea3SApple OSS Distributions<strong>struct  memory_object_perf_info</strong>
8*5e3eaea3SApple OSS Distributions<strong>{</strong>
9*5e3eaea3SApple OSS Distributions        <strong>vm_offset_t</strong>      <var>cluster_size</var><strong>;</strong>
10*5e3eaea3SApple OSS Distributions        <strong>boolean_t</strong>    <var>may_cache_object</var><strong>;</strong>
11*5e3eaea3SApple OSS Distributions<strong>};</strong>
12*5e3eaea3SApple OSS Distributions
13*5e3eaea3SApple OSS Distributions<strong>typedef struct memory_object_perf_info* memory_object_perf_info_t;</strong>
14*5e3eaea3SApple OSS Distributions</pre>
15*5e3eaea3SApple OSS Distributions<h3>FIELDS</h3>
16*5e3eaea3SApple OSS Distributions<dl>
17*5e3eaea3SApple OSS Distributions<dt> <var>cluster_size</var>
18*5e3eaea3SApple OSS Distributions<dd>
19*5e3eaea3SApple OSS DistributionsPreferred cluster size (in bytes) for the memory object.  This helps to
20*5e3eaea3SApple OSS Distributionsdetermine how many pages are transferred in individual data request
21*5e3eaea3SApple OSS Distributionsand return messages.
22*5e3eaea3SApple OSS Distributions<p>
23*5e3eaea3SApple OSS Distributions<dt> <var>may_cache_object</var>
24*5e3eaea3SApple OSS Distributions<dd>
25*5e3eaea3SApple OSS DistributionsCache indicator.  If true, the kernel can cache data associated with the
26*5e3eaea3SApple OSS Distributionsmemory object (keep the memory object active) even if no virtual
27*5e3eaea3SApple OSS Distributionsmemory references to it remain.
28*5e3eaea3SApple OSS Distributions</dl>
29*5e3eaea3SApple OSS Distributions<h3>DESCRIPTION</h3>
30*5e3eaea3SApple OSS Distributions<p>
31*5e3eaea3SApple OSS DistributionsThe <strong>memory_object_perf_info</strong> structure
32*5e3eaea3SApple OSS Distributionsdefines a memory object's character with respect to performance.
33*5e3eaea3SApple OSS Distributions<h3>NOTES</h3>
34*5e3eaea3SApple OSS Distributions<p>
35*5e3eaea3SApple OSS DistributionsSharing cached data among all the clients of a memory object can have a major
36*5e3eaea3SApple OSS Distributionsimpact on performance, especially if it can be extended across successive, as
37*5e3eaea3SApple OSS Distributionswell as concurrent, uses.  For example, the memory objects that represent
38*5e3eaea3SApple OSS Distributionsprogram images can be used regularly by different programs.
39*5e3eaea3SApple OSS DistributionsBy retaining the data
40*5e3eaea3SApple OSS Distributionsfor these memory objects in cache, the number of secondary storage accesses
41*5e3eaea3SApple OSS Distributionscan be reduced significantly.
42*5e3eaea3SApple OSS Distributions<h3>RELATED INFORMATION</h3>
43*5e3eaea3SApple OSS Distributions<p>
44*5e3eaea3SApple OSS DistributionsFunctions:
45*5e3eaea3SApple OSS Distributions<a href="MO_get_attributes.html"><strong>memory_object_get_attributes</strong></a>,
46*5e3eaea3SApple OSS Distributions<a href="MO_change_attributes.html"><strong>memory_object_change_attributes</strong></a>,
47*5e3eaea3SApple OSS Distributions<a href="vm_region.html"><strong>vm_region</strong></a>,
48*5e3eaea3SApple OSS Distributions<a href="memory_object_synchronize.html"><strong>memory_object_synchronize</strong></a>,
49*5e3eaea3SApple OSS Distributions<a href="VSD_memory_manager.html"><strong>vm_set_default_memory_manager</strong></a>,
50*5e3eaea3SApple OSS Distributions<a href="vm_msync.html"><strong>vm_msync</strong></a>.
51*5e3eaea3SApple OSS Distributions<p>
52*5e3eaea3SApple OSS DistributionsStructures:
53*5e3eaea3SApple OSS Distributions<a href="memory_object_attr_info.html"><strong>memory_object_attr_info</strong></a>.
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