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