int
SCOTCH_graphPart (
SCOTCH_Graph * const grafptr, /*+ Graph to map +*/
const SCOTCH_Num partnbr, /*+ Number of parts +*/
SCOTCH_Strat * const stratptr, /*+ Mapping strategy +*/
SCOTCH_Num * const maptab) /*+ Mapping array +*/
{
SCOTCH_Arch archdat;
int o;
SCOTCH_archInit (&archdat);
SCOTCH_archCmplt (&archdat, partnbr);
o = SCOTCH_graphMap (grafptr, &archdat, stratptr, maptab);
SCOTCH_archExit (&archdat);
return (o);
}
// Call scotch with options from dictionary.
Foam::label Foam::scotchDecomp::decompose
(
const List<int>& adjncy,
const List<int>& xadj,
const scalarField& cWeights,
List<int>& finalDecomp
)
{
// Dump graph
if (decompositionDict_.found("scotchCoeffs"))
{
const dictionary& scotchCoeffs =
decompositionDict_.subDict("scotchCoeffs");
if (scotchCoeffs.found("writeGraph"))
{
Switch writeGraph(scotchCoeffs.lookup("writeGraph"));
if (writeGraph)
{
OFstream str(mesh_.time().path() / mesh_.name() + ".grf");
Info<< "Dumping Scotch graph file to " << str.name() << endl
<< "Use this in combination with gpart." << endl;
label version = 0;
str << version << nl;
// Numer of vertices
str << xadj.size()-1 << ' ' << adjncy.size() << nl;
// Numbering starts from 0
label baseval = 0;
// Has weights?
label hasEdgeWeights = 0;
label hasVertexWeights = 0;
label numericflag = 10*hasEdgeWeights+hasVertexWeights;
str << baseval << ' ' << numericflag << nl;
for (label cellI = 0; cellI < xadj.size()-1; cellI++)
{
label start = xadj[cellI];
label end = xadj[cellI+1];
str << end-start;
for (label i = start; i < end; i++)
{
str << ' ' << adjncy[i];
}
str << nl;
}
}
}
}
// Strategy
// ~~~~~~~~
// Default.
SCOTCH_Strat stradat;
check(SCOTCH_stratInit(&stradat), "SCOTCH_stratInit");
if (decompositionDict_.found("scotchCoeffs"))
{
const dictionary& scotchCoeffs =
decompositionDict_.subDict("scotchCoeffs");
string strategy;
if (scotchCoeffs.readIfPresent("strategy", strategy))
{
if (debug)
{
Info<< "scotchDecomp : Using strategy " << strategy << endl;
}
SCOTCH_stratGraphMap(&stradat, strategy.c_str());
//fprintf(stdout, "S\tStrat=");
//SCOTCH_stratSave(&stradat, stdout);
//fprintf(stdout, "\n");
}
}
// Graph
// ~~~~~
List<int> velotab;
// Check for externally provided cellweights and if so initialise weights
scalar minWeights = gMin(cWeights);
if (cWeights.size() > 0)
{
if (minWeights <= 0)
{
WarningIn
(
"scotchDecomp::decompose"
"(const pointField&, const scalarField&)"
) << "Illegal minimum weight " << minWeights
<< endl;
}
if (cWeights.size() != xadj.size()-1)
{
FatalErrorIn
(
"scotchDecomp::decompose"
"(const pointField&, const scalarField&)"
) << "Number of cell weights " << cWeights.size()
<< " does not equal number of cells " << xadj.size()-1
<< exit(FatalError);
}
// Convert to integers.
velotab.setSize(cWeights.size());
forAll(velotab, i)
{
velotab[i] = int(cWeights[i]/minWeights);
}
}
SCOTCH_Graph grafdat;
check(SCOTCH_graphInit(&grafdat), "SCOTCH_graphInit");
check
(
SCOTCH_graphBuild
(
&grafdat,
0, // baseval, c-style numbering
xadj.size()-1, // vertnbr, nCells
xadj.begin(), // verttab, start index per cell into adjncy
&xadj[1], // vendtab, end index ,,
velotab.begin(), // velotab, vertex weights
NULL, // vlbltab
adjncy.size(), // edgenbr, number of arcs
adjncy.begin(), // edgetab
NULL // edlotab, edge weights
),
"SCOTCH_graphBuild"
);
check(SCOTCH_graphCheck(&grafdat), "SCOTCH_graphCheck");
// Architecture
// ~~~~~~~~~~~~
// (fully connected network topology since using switch)
SCOTCH_Arch archdat;
check(SCOTCH_archInit(&archdat), "SCOTCH_archInit");
List<label> processorWeights;
if (decompositionDict_.found("scotchCoeffs"))
{
const dictionary& scotchCoeffs =
decompositionDict_.subDict("scotchCoeffs");
scotchCoeffs.readIfPresent("processorWeights", processorWeights);
}
if (processorWeights.size())
{
if (debug)
{
Info<< "scotchDecomp : Using procesor weights " << processorWeights
<< endl;
}
check
(
SCOTCH_archCmpltw(&archdat, nProcessors_, processorWeights.begin()),
"SCOTCH_archCmpltw"
);
}
else
{
check
(
SCOTCH_archCmplt(&archdat, nProcessors_),
"SCOTCH_archCmplt"
);
}
//SCOTCH_Mapping mapdat;
//SCOTCH_graphMapInit(&grafdat, &mapdat, &archdat, NULL);
//SCOTCH_graphMapCompute(&grafdat, &mapdat, &stradat); /* Perform mapping */
//SCOTCH_graphMapExit(&grafdat, &mapdat);
// Hack:switch off fpu error trapping
# ifdef LINUX_GNUC
int oldExcepts = fedisableexcept
(
FE_DIVBYZERO
| FE_INVALID
| FE_OVERFLOW
);
# endif
finalDecomp.setSize(xadj.size()-1);
finalDecomp = 0;
check
(
SCOTCH_graphMap
(
&grafdat,
&archdat,
&stradat, // const SCOTCH_Strat *
finalDecomp.begin() // parttab
),
"SCOTCH_graphMap"
);
# ifdef LINUX_GNUC
feenableexcept(oldExcepts);
# endif
//finalDecomp.setSize(xadj.size()-1);
//check
//(
// SCOTCH_graphPart
// (
// &grafdat,
// nProcessors_, // partnbr
// &stradat, // const SCOTCH_Strat *
// finalDecomp.begin() // parttab
// ),
// "SCOTCH_graphPart"
//);
// Release storage for graph
SCOTCH_graphExit(&grafdat);
// Release storage for strategy
SCOTCH_stratExit(&stradat);
// Release storage for network topology
SCOTCH_archExit(&archdat);
return 0;
}
static
void run_scotch( Container &c,
MapContainer &mapping,
const std::size_t cores,
weight_function_t weight_func,
void *weight )
{
#if 0
static_assert( std::is_signed<
std::remove_reference< decltype( c.end() ) >::type >::value,
"Container must have signed types so that -1 may signify no mapping" );
#endif
raftgraph_t raft_graph;
get_graph_info( c,
raft_graph,
weight_func,
nullptr );
SCOTCH_Graph graph;
if( SCOTCH_graphInit( &graph ) != 0 )
{
/** TODO, add RaftLib Exception **/
std::cerr << "Failed to initialize graph!!\n";
exit( EXIT_FAILURE );
}
auto table( raft_graph.getScotchTables() );
if( SCOTCH_graphBuild(
&graph /** graph ptr **/,
0 /** base value **/,
table.num_vertices /** vertex nmbr (zero indexed) **/,
table.vtable /** vertex tab **/,
&table.vtable[ 1 ] /** vendtab **/,
nullptr /** velotab **/,
nullptr /** vlbltab **/,
table.num_edges /** edge number **/,
table.etable /** edge tab **/,
table.eweight /** edlotab **/
) != 0 )
{
/** TODO, add RaftLib Exception **/
std::cerr << "Failed to build graph\n";
exit( EXIT_FAILURE );
}
if( SCOTCH_graphCheck( &graph ) != 0 )
{
/** TODO, add RaftLib Exception **/
std::cerr << "Graph is inconsistent\n";
std::remove_reference< decltype( table ) >::type::print( std::cerr, table );
std::cerr << "\n";
raft_graph.print( std::cerr );
exit( EXIT_FAILURE );
}
/** TODO, we can do much more with this arch file **/
SCOTCH_Arch archdat;
if( SCOTCH_archInit( &archdat ) != 0 )
{
/** TODO, add RaftLib Exception **/
std::cerr << "Architecture initialization failed\n";
exit( EXIT_FAILURE );
}
/** core are equal **/
if( SCOTCH_archCmplt( &archdat, cores /** num cores **/) != 0 )
{
/** TODO, add RaftLib Exception **/
std::cerr << "Failed to create architecture file\n";
exit( EXIT_FAILURE );
}
/** strategy **/
SCOTCH_Strat stradat;
if( SCOTCH_stratInit( &stradat ) != 0 )
{
/** TODO, add RaftLib Exception **/
std::cerr << "Failed to init strategy!!\n";
exit( EXIT_FAILURE );
}
/** build recursive strategy **/
if( SCOTCH_stratGraphClusterBuild(
&stradat,
SCOTCH_STRATSPEED,
cores,
.75,
.01) != 0 )
{
/** TODO, add RaftLib Exception **/
std::cerr << "Failed to map strategy graph!!\n";
exit( EXIT_FAILURE );
}
if( SCOTCH_graphMap(
&graph /** graph ptr **/,
&archdat,
&stradat,
table.partition /** parttab **/
) != 0 )
{
/** TODO, add RaftLib Exception **/
std::cerr << "Failed to map!!\n";
exit( EXIT_FAILURE );
}
/**
* first case is for if we've mapped all vertices,
* second is for when some of the kernels are innactive
* in which case the number of vertices in the
* table will be less than the size of c in which case
* we need to get which vertices (the actual number id
* from the application) are mapped and to where, the
* returned table in mapping must include even the
* vertices that aren't active (indicated by a -1) so
* that the returning loop can be as simple as possible
*/
if( c.size() == table.num_vertices )
{
/** copy mapping **/
for( auto i( 0 ); i < table.num_vertices; i++ )
{
mapping.emplace_back( table.partition[ i ] );
}
}
else
{
const auto &vmapping( raft_graph.getVertexNumbersAtIndicies() );
auto it_map_index( vmapping.cbegin() );
auto table_index( 0 );
const auto size( c.size() );
for( auto i( 0 ); i < size; i++ )
{
if( i == (*it_map_index) && it_map_index != vmapping.cend() )
{
mapping.emplace_back( table.partition[ table_index++ ] );
++it_map_index;
}
else
{
mapping.emplace_back( -1 );
}
}
}
/** call exit graph **/
SCOTCH_graphExit( &graph );
SCOTCH_stratExit( &stradat );
SCOTCH_archExit ( &archdat );
return;
}
/* Internal function : kPartBoxCompute
* it computes a new numbering of graph vertices, using a k-partitioning.
* Assuming that baseval of the graph is 1
*
* - graf : the input graph
* - vertNbr : the number of vertices
* - boxVertNbr : the number of vertices of each box
* - permVrtTab : the new numbering
*
* returning 0 if OK, 1 else
*/
int kPartBoxCompute(SCOTCH_Graph graf, int vertNbr, int boxVertNbr, SCOTCH_Num *permVrtTab) {
int boxNbr, vertIdx;
SCOTCH_Num logMaxVal, SupMaxVal, InfMaxVal, maxVal;
char s[200];
SCOTCH_Num *sortPartTb;
SCOTCH_Strat strat ;
SCOTCH_Arch arch;
/* Computing the number of boxes */
boxNbr = vertNbr / boxVertNbr;
if (boxNbr * boxVertNbr != vertNbr) {
boxNbr = boxNbr + 1;
}
/* Initializing SCOTCH functions */
CHECK_SCOTCH(SCOTCH_stratInit(&strat), "scotch_stratInit", 0) ;
CHECK_SCOTCH(SCOTCH_archVcmplt(&arch), "scotch_archVcmplt", 0) ;
sprintf(s, "m{vert=%d,low=r{job=t,map=t,poli=S,sep=m{type=h,vert=80,low=h{pass=10}f{bal=0.0005,move=80},asc=f{bal=0.005,move=80}}}}", vertNbr / boxVertNbr);
CHECK_SCOTCH(SCOTCH_stratGraphMap(&strat, s), "scotch_stratGraphMap", 0) ;
sortPartTb= (SCOTCH_Num *)M_calloc(2*vertNbr, sizeof(SCOTCH_Num), "boxCompute");
/* Partionning the graph */
CHECK_SCOTCH(SCOTCH_graphMap(&graf, &arch, &strat, sortPartTb), "scotch_graphMap", 0);
// Looking for the max value in sortPartTb and computing sortPartTb as
// followed :
// - sortPartTb[2i] is the box value
// - sortPartTb[2i+1] is the vertex number
maxVal = sortPartTb[0];
for (vertIdx = vertNbr - 1 ; vertIdx >= 0 ; vertIdx--) {
sortPartTb[2*vertIdx] = sortPartTb[vertIdx];
sortPartTb[2*vertIdx+1] = vertIdx + 1;
if (sortPartTb[vertIdx] > maxVal)
maxVal = sortPartTb[vertIdx];
}
// Determining the log of MaxVal
logMaxVal = 0;
while ( maxVal > 0) {
logMaxVal++;
maxVal >>= 1;
}
// Infering the interval in which box values will be
InfMaxVal = logMaxVal << logMaxVal;
SupMaxVal = (logMaxVal << (logMaxVal + 1)) - 1;
// Increasing box values until they are in the previous interval
for (vertIdx = 0 ; vertIdx < vertNbr ; vertIdx++) {
while (!(sortPartTb[2*vertIdx] >= InfMaxVal && sortPartTb[2*vertIdx] <= SupMaxVal)) {
sortPartTb[2*vertIdx] <<= 1;
}
}
// Sorting the tabular, which contains box values and vertex numbers
_SCOTCHintSort2asc1(sortPartTb, vertNbr);
/* Infering the new numbering */
for (vertIdx = 0; vertIdx < vertNbr ; vertIdx++) {
permVrtTab[sortPartTb[2*vertIdx + 1]] = vertIdx + 1;
}
SCOTCH_stratExit(&strat) ;
SCOTCH_archExit(&arch) ;
M_free(sortPartTb);
return 0;
}
