You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
174 lines
8.9 KiB
174 lines
8.9 KiB
2 years ago
|
<!-------- @HEADER
|
||
|
|
!
|
||
|
|
! !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
|
||
|
|
!
|
||
|
|
! Zoltan Toolkit for Load-balancing, Partitioning, Ordering and Coloring
|
||
|
|
! Copyright 2012 Sandia Corporation
|
||
|
|
!
|
||
|
|
! Under the terms of Contract DE-AC04-94AL85000 with Sandia Corporation,
|
||
|
|
! the U.S. Government retains certain rights in this software.
|
||
|
|
!
|
||
|
|
! Redistribution and use in source and binary forms, with or without
|
||
|
|
! modification, are permitted provided that the following conditions are
|
||
|
|
! met:
|
||
|
|
!
|
||
|
|
! 1. Redistributions of source code must retain the above copyright
|
||
|
|
! notice, this list of conditions and the following disclaimer.
|
||
|
|
!
|
||
|
|
! 2. Redistributions in binary form must reproduce the above copyright
|
||
|
|
! notice, this list of conditions and the following disclaimer in the
|
||
|
|
! documentation and/or other materials provided with the distribution.
|
||
|
|
!
|
||
|
|
! 3. Neither the name of the Corporation nor the names of the
|
||
|
|
! contributors may be used to endorse or promote products derived from
|
||
|
|
! this software without specific prior written permission.
|
||
|
|
!
|
||
|
|
! THIS SOFTWARE IS PROVIDED BY SANDIA CORPORATION "AS IS" AND ANY
|
||
|
|
! EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
|
||
|
|
! IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
|
||
|
|
! PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL SANDIA CORPORATION OR THE
|
||
|
|
! CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
|
||
|
|
! EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
|
||
|
|
! PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
|
||
|
|
! PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
|
||
|
|
! LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
|
||
|
|
! NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
|
||
|
|
! SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
|
||
|
|
!
|
||
|
|
! Questions? Contact Karen Devine kddevin@sandia.gov
|
||
|
|
! Erik Boman egboman@sandia.gov
|
||
|
|
!
|
||
|
|
! !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
|
||
|
|
!
|
||
|
|
! @HEADER
|
||
|
|
------->
|
||
|
|
<!doctype html public "-//w3c//dtd html 4.0 transitional//en">
|
||
|
|
<html>
|
||
|
|
<head>
|
||
|
|
<meta http-equiv="Content-Type" content="text/html; charset=iso-8859-1">
|
||
|
|
<meta name="GENERATOR" content="Mozilla/4.7 [en] (X11; U; SunOS 5.7 sun4u) [Netscape]">
|
||
|
|
<meta name="sandia.approval_type" content="formal">
|
||
|
|
<meta name="sandia.approved" content="SAND2007-4748W">
|
||
|
|
<meta name="author" content="Zoltan PI">
|
||
|
|
|
||
|
|
<title>Zoltan User's Guide: Load-Balancing Examples</title>
|
||
|
|
|
||
|
|
</head>
|
||
|
|
<body bgcolor="#FFFFFF">
|
||
|
|
|
||
|
|
<div align=right><b><i><a href="ug.html">Zoltan User's Guide</a>
|
||
|
|
| <a href="ug_examples_mig.html">Next</a> | <a href="ug_examples_init.html">Previous</a></i></b></div>
|
||
|
|
|
||
|
|
<h2>
|
||
|
|
<a NAME="Load-Balancing Example"></a>Load-Balancing Example</h2>
|
||
|
|
An example of the typical calling sequence for load balancing using Zoltan
|
||
|
|
in a finite element application is shown in the <a href="#LB Example Fig">figure</a>
|
||
|
|
below. An application first selects a load-balancing algorithm
|
||
|
|
by setting the <a href="ug_alg.html#LB_METHOD"><i>LB_METHOD</i></a> parameter
|
||
|
|
with
|
||
|
|
<b><a href="ug_interface_init.html#Zoltan_Set_Param">Zoltan_Set_Param</a></b>.
|
||
|
|
Next, other parameter values are set by calls to
|
||
|
|
<b><a href="ug_interface_init.html#Zoltan_Set_Param">Zoltan_Set_Param</a></b>.
|
||
|
|
After some computation, load balancing is invoked by calling <b><a href="ug_interface_lb.html#Zoltan_LB_Partition">Zoltan_LB_Partition</a></b>.
|
||
|
|
The results of the load balancing include the number of nodes to be imported
|
||
|
|
and exported to the processor, lists of global and local IDs of the imported
|
||
|
|
and exported nodes, and source and destination processors of the imported
|
||
|
|
and exported nodes. A returned argument of <b><a href="ug_interface_lb.html#Zoltan_LB_Partition">Zoltan_LB_Partition</a></b>
|
||
|
|
is tested to see whether the new decomposition differs from the old one.
|
||
|
|
If the decompositions differ, some sort of data migration is needed to
|
||
|
|
establish the new decomposition; the details of migration are not shown
|
||
|
|
in this <a href="#LB Example Fig">figure</a> but will be addressed in the
|
||
|
|
<a href="ug_examples_mig.html">migration
|
||
|
|
examples</a>. After the data migration is completed, the arrays of information
|
||
|
|
about imported and exported nodes returned by <b><a href="ug_interface_lb.html#Zoltan_LB_Partition">Zoltan_LB_Partition</a></b>
|
||
|
|
are freed by a call to <b><a href="ug_interface_lb.html#Zoltan_LB_Free_Part">Zoltan_LB_Free_Part</a></b>.
|
||
|
|
<br>
|
||
|
|
<br>
|
||
|
|
<center><table BORDER=2 COLS=1 WIDTH="90%" NOSAVE >
|
||
|
|
<tr>
|
||
|
|
<td><a NAME="LB Example Fig"></a><tt>char *lb_method;</tt>
|
||
|
|
<br><tt>int new, num_imp, num_exp, *imp_procs, *exp_procs;</tt>
|
||
|
|
<br><tt>int *imp_to_part, *exp_to_part;</tt>
|
||
|
|
<br><tt>int num_gid_entries, num_lid_entries;</tt>
|
||
|
|
<br><tt><a href="ug_usage.html#Data Types for Object IDs">ZOLTAN_ID_PTR</a> imp_global_ids,
|
||
|
|
exp_global_ids;</tt>
|
||
|
|
<br><tt><a href="ug_usage.html#Data Types for Object IDs">ZOLTAN_ID_PTR</a>
|
||
|
|
imp_local_ids, exp_local_ids;</tt>
|
||
|
|
<p><tt>/* <i>Set load-balancing method.</i> */</tt>
|
||
|
|
<br><tt>read_load_balancing_info_from_input_file(&lb_method);</tt>
|
||
|
|
<br><tt><a href="ug_interface_init.html#Zoltan_Set_Param">Zoltan_Set_Param</a>(zz,
|
||
|
|
"LB_METHOD", lb_method);</tt>
|
||
|
|
<p><tt>/* <i>Reset some load-balancing parameters.</i> */</tt>
|
||
|
|
<br><tt><a href="ug_interface_init.html#Zoltan_Set_Param">Zoltan_Set_Param</a>(zz,
|
||
|
|
"RCB_Reuse", "TRUE");</tt>
|
||
|
|
<p><tt>/* <i>Perform computations</i> */</tt>
|
||
|
|
<br><tt>...</tt>
|
||
|
|
<br><tt>/* <i>Perform load balancing</i> */</tt>
|
||
|
|
<br><tt><a href="ug_interface_lb.html#Zoltan_LB_Partition">Zoltan_LB_Partition</a>(zz,&new,&num_gid_entries,&num_lid_entries,</tt>
|
||
|
|
<br><tt> &num_imp,&imp_global_ids,&imp_local_ids,&imp_procs,&imp_to_part,</tt>
|
||
|
|
<br><tt> &num_exp,&exp_global_ids,&exp_local_ids,&exp_procs,&exp_to_part); </tt>
|
||
|
|
<br><tt>if (new)</tt>
|
||
|
|
<br><tt> perform_data_migration(...);</tt>
|
||
|
|
<p><tt>/* <i>Free memory allocated for load-balancing results by Zoltan library</i>
|
||
|
|
*/</tt>
|
||
|
|
<br><tt><a href="ug_interface_lb.html#Zoltan_LB_Free_Part">Zoltan_LB_Free_Part</a>(&imp_global_ids,
|
||
|
|
&imp_local_ids, &imp_procs, &imp_to_part);</tt>
|
||
|
|
<br><tt><a href="ug_interface_lb.html#Zoltan_LB_Free_Part">Zoltan_LB_Free_Part</a>(&exp_global_ids,
|
||
|
|
&exp_local_ids, &exp_procs, &exp_to_part);</tt>
|
||
|
|
<br><tt>...</tt>
|
||
|
|
</td>
|
||
|
|
</tr>
|
||
|
|
|
||
|
|
<caption ALIGN=BOTTOM><i>Typical calling sequence for performing load balancing
|
||
|
|
with the Zoltan library.</i></caption>
|
||
|
|
</table></center>
|
||
|
|
|
||
|
|
<br>
|
||
|
|
<center><table BORDER=2 COLS=1 WIDTH="90%" NOSAVE >
|
||
|
|
<tr>
|
||
|
|
<td><tt>character(len=3) lb_method</tt>
|
||
|
|
<br><tt>logical new</tt>
|
||
|
|
<br><tt>integer(Zoltan_INT) num_imp, num_exp</tt>
|
||
|
|
<br><tt>integer(Zoltan_INT) num_gid_entries, num_lid_entries </tt>
|
||
|
|
<br><tt>integer(Zoltan_INT), pointer :: imp_procs(:), exp_procs(:)</tt>
|
||
|
|
<br><tt>integer(Zoltan_INT), pointer :: imp_global_ids(:), exp_global_ids(:)
|
||
|
|
! global IDs</tt>
|
||
|
|
<br><tt>integer(Zoltan_INT), pointer :: imp_local_ids(:), exp_local_ids(:)
|
||
|
|
! local IDs</tt>
|
||
|
|
<br><tt>integer(Zoltan_INT) ierr</tt>
|
||
|
|
<p><tt>! <i>Set load-balancing method.</i></tt>
|
||
|
|
<br><tt>lb_method = "RCB"</tt>
|
||
|
|
<br><tt>ierr = <a href="ug_interface_init.html#Zoltan_Set_Param">Zoltan_Set_Param</a>(zz, "LB_METHOD",
|
||
|
|
lb_method)</tt>
|
||
|
|
<p><tt>! <i>Reset some load-balancing parameters</i></tt>
|
||
|
|
<br><tt>ierr = <a href="ug_interface_init.html#Zoltan_Set_Param">Zoltan_Set_Param</a>(zz,
|
||
|
|
"RCB_Reuse", "TRUE")</tt>
|
||
|
|
<p><tt>! <i>Perform computations</i></tt>
|
||
|
|
<br><tt>...</tt>
|
||
|
|
<br><tt>! <i>Perform load balancing</i></tt>
|
||
|
|
<br><tt>ierr = <a href="ug_interface_lb.html#Zoltan_LB_Partition">Zoltan_LB_Partition</a>(zz,new,num_gid_entries,num_lid_entries, &</tt>
|
||
|
|
<br><tt> num_imp,imp_global_ids,imp_local_ids,
|
||
|
|
&</tt>
|
||
|
|
<br><tt> imp_procs,imp_to_part, &</tt>
|
||
|
|
<br><tt> num_exp,exp_global_ids,exp_local_ids, &</tt>
|
||
|
|
<br><tt> exp_procs,exp_to_part) </tt>
|
||
|
|
<br><tt>if (new) then</tt>
|
||
|
|
<br><tt> perform_data_migration(...)</tt>
|
||
|
|
<br><tt>endif</tt>
|
||
|
|
<p><tt>! <i>Free memory allocated for load-balancing results by Zoltan library</i></tt>
|
||
|
|
<br><tt>ierr = <a href="ug_interface_lb.html#Zoltan_LB_Free_Part">Zoltan_LB_Free_Part</a>(imp_global_ids, imp_local_ids, imp_procs, imp_to_part);</tt>
|
||
|
|
<br><tt>ierr = <a href="ug_interface_lb.html#Zoltan_LB_Free_Part">Zoltan_LB_Free_Part</a>(exp_global_ids, exp_local_ids, exp_procs, exp_to_part);</tt>
|
||
|
|
<br><tt>...</tt></td>
|
||
|
|
</tr>
|
||
|
|
|
||
|
|
<caption ALIGN=BOTTOM><i>Fortran version of the load-balancing example.</i></caption>
|
||
|
|
</table></center>
|
||
|
|
|
||
|
|
<p>
|
||
|
|
<hr WIDTH="100%">[<a href="ug.html">Table of Contents</a> |
|
||
|
|
<a href="ug_examples_mig.html">Next:
|
||
|
|
Migration Examples</a> | <a href="ug_examples_init.html">Previous:
|
||
|
|
General Usage Example</a> | <a href="https://www.sandia.gov/general/privacy-security/index.html">Privacy and Security</a>]
|
||
|
|
</body>
|
||
|
|
</html>
|