osfmk/man/default_pager_add_segment.html

   1 <h2>default_pager_add_segment</h2>
   2 <hr>
   3 <p>
   4 <strong>Server Interface</strong> - Add additional backing storage for a default pager.
   5 <h3>SYNOPSIS</h3>
   6 <pre>
   7 <strong>#include&lt mach/default_pager_object.h&gt</strong>
   8
   9 <strong>kern_return_t   default_pager_add_segment</strong>
  10                 <strong>(mach_port_t</strong>                      <var>backing_store</var>,
  11                  <strong>mach_port_t</strong>                             <var>device</var>,
  12                  <strong>recnum_t</strong>                                <var>offset</var>,
  13                  <strong>recnum_t</strong>                                 <var>count</var>,
  14                  <strong>int</strong>                                <var>record_size</var><strong>);</strong>
  15 </pre>
  16 <h3>PARAMETERS</h3>
  17 <dl>
  18 <p>
  19 <dt> <var>backing_store</var>
  20 <dd>
  21 [in backing store (receive) right] The backing store port.
  22 <p>
  23 <dt> <var>device</var>
  24 <dd>
  25 [in device port] The port for the device containing the backing storage
  26 partition.
  27 <p>
  28 <dt> <var>offset</var>
  29 <dd>
  30 [in scalar] The offset, in <var>record_size units</var>, to the beginning of the
  31 backing storage on the device.
  32 <p>
  33 <dt> <var>count</var>
  34 <dd>
  35 [in scalar] The number of <var>record_size</var> units
  36 in the partition/segment.
  37 <p>
  38 <dt> <var>record_size</var>
  39 <dd>
  40 [in scalar] The size, in bytes, of the storage device record.
  41 </dl>
  42 <h3>DESCRIPTION</h3>
  43 <p>
  44 The <strong>default_pager_add_segment</strong> function is called to add a partition to
  45 a default pager's backing storage (i.e. expand the amount of backing
  46 storage available to a memory manager). The kernel does not make
  47 this call itself (which is why it can be a synchronous call); this
  48 request is only issued by tasks holding the backing store port,
  49 created with <strong>default_pager_backing_store_create</strong>, for a default memory
  50 manager.
  51 The result is that the pager may use count records on device starting
  52 at offset for paging, and each record is record_size bytes in length
  53 (note that the device_* calls are, or can be, record oriented).
  54 <h3>RETURN VALUES</h3>
  55 <dl>
  56 <p>
  57 <dt> <strong>KERN_FAILURE</strong>
  58 <dd>
  59 The default pager does not support this operation.
  60 <p>
  61 <dt> <strong>KERN_INVALID_ARGUMENT</strong>
  62 <dd>
  63 The <var>backing_store</var> port does not represent a valid backing store or the
  64 specified segment overlaps an existing partition.
  65 <p>
  66 <dt> <strong>KERN_RESOURCE_SHORTAGE</strong>
  67 <dd>
  68 The default pager is unable to allocate internal resources
  69      to manage the new backing storage.
  70 <p>
  71 <dt> <strong>KERN_SUCCESS</strong>
  72 <dd>
  73 The operation was successful.
  74 </dl>
  75 <h3>RELATED INFORMATION</h3>
  76 <p>
  77 Functions:
  78 <a href="DP_backing_store_create.html"><strong>default_pager_backing_store_create</strong></a>,
  79 <a href="DP_backing_store_delete.html"><strong>default_pager_backing_store_delete</strong></a>,
  80 <a href="DP_backing_store_info.html"><strong>default_pager_backing_store_info</strong></a>.