int
SCOTCH_graphMapCompute (
SCOTCH_Graph * const grafptr, /*+ Graph to order +*/
SCOTCH_Mapping * const mappptr, /*+ Mapping to compute +*/
SCOTCH_Strat * const stratptr) /*+ Mapping strategy +*/
{
Kgraph mapgrafdat; /* Effective mapping graph */
const Strat * mapstratptr; /* Pointer to mapping strategy */
LibMapping * restrict lmapptr;
int o;
#ifdef SCOTCH_DEBUG_GRAPH2
if (graphCheck ((Graph *) grafptr) != 0) {
errorPrint ("SCOTCH_graphMapCompute: invalid input graph");
return (1);
}
#endif /* SCOTCH_DEBUG_GRAPH2 */
lmapptr = (LibMapping *) mappptr;
if (*((Strat **) stratptr) == NULL) { /* Set default mapping strategy if necessary */
ArchDom archdomnorg;
archDomFrst (&lmapptr->m.archdat, &archdomnorg);
if (archVar (&lmapptr->m.archdat))
SCOTCH_stratGraphClusterBuild (stratptr, 0, 1, 0.0, 0.05);
else
SCOTCH_stratGraphMapBuild (stratptr, 0, archDomSize (&lmapptr->m.archdat, &archdomnorg), 0.05);
}
mapstratptr = *((Strat **) stratptr);
if (mapstratptr->tabl != &kgraphmapststratab) {
errorPrint ("SCOTCH_graphMapCompute: not a graph mapping strategy");
return (1);
}
if (kgraphInit (&mapgrafdat, (Graph *) grafptr, &lmapptr->m) != 0)
return (1);
o = kgraphMapSt (&mapgrafdat, mapstratptr); /* Perform mapping */
lmapptr->m.domnmax = mapgrafdat.m.domnmax; /* Do not free the mapping, as it has been cloned */
lmapptr->m.domnnbr = mapgrafdat.m.domnnbr;
lmapptr->m.domntab = mapgrafdat.m.domntab; /* Update pointer to domntab in case it has changed */
mapgrafdat.m.parttax = NULL; /* Prevent mapping arrays from being freed by graph */
mapgrafdat.m.domntab = NULL;
kgraphExit (&mapgrafdat);
if (lmapptr->parttax != NULL) { /* Propagate mapping data to user partition array */
Gnum vertnum;
Gnum vertnnd;
for (vertnum = lmapptr->m.baseval, vertnnd = vertnum + lmapptr->m.vertnbr;
vertnum < vertnnd; vertnum ++)
lmapptr->parttax[vertnum] = archDomNum (&lmapptr->m.archdat, &lmapptr->m.domntab[lmapptr->m.parttax[vertnum]]);
}
return (o);
}
int
SCOTCH_graphMapView (
const SCOTCH_Graph * const libgrafptr,
const SCOTCH_Mapping * const libmappptr,
FILE * const stream)
{
const Graph * restrict grafptr;
const Mapping * restrict mappptr;
Anum * restrict parttax; /* Part array */
MappingSort * restrict domntab; /* Pointer to domain sort array */
ArchDom domnfrst; /* Largest domain in architecture */
Anum tgtnbr; /* Number of processors in target topology */
Anum mapnbr; /* Number of processors effectively used */
Anum mapnum;
double mapavg; /* Average mapping weight */
Gnum mapmin;
Gnum mapmax;
Gnum mapsum; /* (Partial) sum of vertex loads */
double mapdlt;
double mapmmy; /* Maximum / average ratio */
Anum * restrict nghbtab; /* Table storing neighbors of current subdomain */
Anum nghbnbr;
Anum nghbmin;
Anum nghbmax;
Anum nghbsum;
Gnum vertnum;
Gnum veloval;
Gnum edloval;
Gnum commdist[256]; /* Array of load distribution */
Gnum commload; /* Total edge load (edge sum) */
Gnum commdilat; /* Total edge dilation */
Gnum commexpan; /* Total edge expansion */
Anum distmax;
Anum distval;
Gnum diammin;
Gnum diammax;
Gnum diamsum;
const Gnum * restrict const verttax = ((Graph *) libgrafptr)->verttax;
const Gnum * restrict const vendtax = ((Graph *) libgrafptr)->vendtax;
const Gnum * restrict const velotax = ((Graph *) libgrafptr)->velotax;
const Gnum * restrict const edgetax = ((Graph *) libgrafptr)->edgetax;
const Gnum * restrict const edlotax = ((Graph *) libgrafptr)->edlotax;
grafptr = (Graph *) libgrafptr;
mappptr = &((LibMapping *) libmappptr)->m;
if ((grafptr->vertnbr == 0) || /* Return if nothing to do */
(grafptr->edgenbr == 0))
return (0);
if (memAllocGroup ((void **) (void *)
&domntab, (size_t) ((grafptr->vertnbr + 1) * sizeof (MappingSort)),
&parttax, (size_t) (grafptr->vertnbr * sizeof (Anum)),
&nghbtab, (size_t) ((grafptr->vertnbr + 2) * sizeof (Anum)), NULL) == NULL) {
errorPrint ("SCOTCH_graphMapView: out of memory");
return (1);
}
memSet (parttax, ~0, grafptr->vertnbr * sizeof (Anum));
for (vertnum = 0; vertnum < grafptr->vertnbr; vertnum ++) {
parttax[vertnum] =
domntab[vertnum].labl = archDomNum (&mappptr->archdat, mapDomain (mappptr, vertnum + grafptr->baseval));
domntab[vertnum].peri = vertnum + grafptr->baseval; /* Build inverse permutation */
}
domntab[grafptr->vertnbr].labl = ARCHDOMNOTTERM; /* TRICK: avoid testing (i+1) */
domntab[grafptr->vertnbr].peri = ~0; /* Prevent Valgrind from yelling */
parttax -= grafptr->baseval; /* From now on, base part array */
intSort2asc2 (domntab, grafptr->vertnbr); /* Sort domain label array by increasing target labels */
archDomFrst (&mappptr->archdat, &domnfrst); /* Get architecture domain */
tgtnbr = archDomSize (&mappptr->archdat, &domnfrst); /* Get architecture size */
mapsum = 0;
mapnbr = 0;
veloval = 1; /* Assume unweighted vertices */
for (vertnum = 0; domntab[vertnum].labl != ARCHDOMNOTTERM; vertnum ++) {
parttax[domntab[vertnum].peri] = mapnbr; /* Build map of partition parts starting from 0 */
if (domntab[vertnum].labl != domntab[vertnum + 1].labl) /* TRICK: if new (or end) domain label */
mapnbr ++;
if (velotax != NULL)
veloval = velotax[domntab[vertnum].peri];
mapsum += veloval;
}
mapavg = (mapnbr == 0) ? 0.0L : (double) mapsum / (double) mapnbr;
mapsum = 0;
mapmin = GNUMMAX;
mapmax = 0;
mapdlt = 0.0L;
for (vertnum = 0; domntab[vertnum].labl != ARCHDOMNOTTERM; vertnum ++) {
if (velotax != NULL)
veloval = velotax[domntab[vertnum].peri];
mapsum += veloval;
if (domntab[vertnum].labl != domntab[vertnum + 1].labl) { /* TRICK: if new (or end) domain label */
if (mapsum < mapmin)
mapmin = mapsum;
if (mapsum > mapmax)
mapmax = mapsum;
mapdlt += fabs ((double) mapsum - mapavg);
mapsum = 0; /* Reset domain load sum */
}
}
mapdlt = (mapnbr != 0) ? mapdlt / ((double) mapnbr * mapavg) : 0.0L;
mapmmy = (mapnbr != 0) ? (double) mapmax / (double) mapavg : 0.0L;
if (mapnbr > tgtnbr) { /* If more subdomains than architecture size */
#ifdef SCOTCH_DEBUG_MAP2
if (! archVar (&mappptr->archdat)) { /* If not a variable-sized architecture */
errorPrint ("SCOTCH_graphMapView: invalid mapping");
memFree (domntab); /* Free group leader */
return (1);
}
#endif /* SCOTCH_DEBUG_MAP2 */
tgtnbr = mapnbr; /* Assume it is a variable-sized architecture */
}
fprintf (stream, "M\tProcessors " GNUMSTRING "/" GNUMSTRING " (%g)\n",
(Gnum) mapnbr,
(Gnum) tgtnbr,
(double) mapnbr / (double) tgtnbr);
fprintf (stream, "M\tTarget min=" GNUMSTRING "\tmax=" GNUMSTRING "\tavg=%g\tdlt=%g\tmaxavg=%g\n",
(Gnum) mapmin,
(Gnum) mapmax,
mapavg,
mapdlt,
mapmmy);
nghbnbr = 0;
nghbmin = ANUMMAX;
nghbmax = 0;
nghbsum = 0;
nghbnbr = 0;
nghbtab[0] = -2;
for (vertnum = 0; domntab[vertnum].labl != ARCHDOMNOTTERM; vertnum ++) {
Gnum edgenum;
Gnum edgennd;
Anum partnum;
partnum = parttax[domntab[vertnum].peri];
for (edgenum = verttax[domntab[vertnum].peri],
edgennd = vendtax[domntab[vertnum].peri];
edgenum < edgennd; edgenum ++) {
Anum partend;
partend = parttax[edgetax[edgenum]];
if ((partend != partnum) && /* If edge is not internal */
(partend != nghbtab[nghbnbr])) { /* And neighbor is not sole neighbor or has not just been found */
Anum partmin;
Anum partmax;
partmin = 0;
partmax = nghbnbr;
while ((partmax - partmin) > 1) {
Anum partmed;
partmed = (partmax + partmin) >> 1;
if (nghbtab[partmed] > partend)
partmax = partmed;
else
partmin = partmed;
}
if (nghbtab[partmin] == partend) /* If neighboring part found, skip to next neighbor */
continue;
#ifdef SCOTCH_DEBUG_MAP2
if (nghbnbr >= (grafptr->vertnbr + 1)) {
errorPrint ("SCOTCH_graphMapView: internal error");
return (1);
}
#endif /* SCOTCH_DEBUG_MAP2 */
nghbnbr ++;
for (partmax = nghbnbr; partmax > (partmin + 1); partmax --)
nghbtab[partmax] = nghbtab[partmax - 1];
nghbtab[partmin + 1] = partend; /* Add new neighbor part in the right place */
}
}
if (domntab[vertnum].labl != domntab[vertnum + 1].labl) { /* TRICK: if new (or end) domain label */
if (nghbnbr < nghbmin)
nghbmin = nghbnbr;
if (nghbnbr > nghbmax)
nghbmax = nghbnbr;
nghbsum += nghbnbr;
nghbnbr = 0;
}
}
int
SCOTCH_dgraphMapView (
SCOTCH_Dgraph * const libgrafptr,
const SCOTCH_Dmapping * const libmappptr,
FILE * const stream)
{
Dgraph * restrict grafptr;
const LibDmapping * restrict mappptr;
ArchDom domnfrst; /* Largest domain in architecture */
unsigned int * restrict nmskloctab; /* Local neighbor bitfield */
unsigned int * restrict nmskglbtab; /* Local neighbor bitfield */
int nmskidxnbr; /* Size of bitfield; int since sent by MPI */
Gnum * restrict tgloloctab; /* Local array of terminal domain loads */
Gnum * restrict tgloglbtab; /* Global array of terminal domain loads */
Gnum * restrict termgsttax; /* Terminal domain ghost mapping array */
Anum tgtnbr; /* Number of processors in target topology */
Anum tgtnum;
Anum mapnbr; /* Number of processors effectively used */
double mapavg; /* Average mapping weight */
Gnum mapmin;
Gnum mapmax;
Gnum mapsum; /* (Partial) sum of vertex loads */
double mapdlt;
double mapmmy; /* Maximum / average ratio */
Anum ngbsum;
Anum ngbmin;
Anum ngbmax;
Gnum vertlocnum;
Gnum veloval;
Gnum edloval;
Gnum commlocdist[256 + 3]; /* Array of local load distribution */
Gnum commglbdist[256 + 3];
Gnum commlocload; /* Total local edge load (edge sum) */
Gnum commlocdilat; /* Total edge dilation */
Gnum commlocexpan; /* Total edge expansion */
Anum distmax;
Anum distval;
int cheklocval;
int chekglbval;
DgraphHaloRequest requdat;
grafptr = (Dgraph *) libgrafptr;
mappptr = (LibDmapping *) libmappptr;
if ((grafptr->vertglbnbr == 0) || /* Return if nothing to do */
(grafptr->edgeglbnbr == 0))
return (0);
archDomFrst (&mappptr->m.archdat, &domnfrst); /* Get architecture domain */
tgtnbr = archDomSize (&mappptr->m.archdat, &domnfrst); /* Get architecture size */
if (archVar (&mappptr->m.archdat)) {
errorPrint ("SCOTCH_dgraphMapView: not implemented");
return (1);
}
if (dgraphGhst (grafptr) != 0) { /* Compute ghost edge array if not already present */
errorPrint ("SCOTCH_dgraphMapView: cannot compute ghost edge array");
return (1);
}
nmskidxnbr = (tgtnbr + 1 + ((sizeof (int) << 3) - 1)) / (sizeof (int) << 3); /* Size of neighbor subdomain bitfield; TRICK: "+1" to have a "-1" cell for unmapped vertices */
cheklocval = 0;
if (memAllocGroup ((void **) (void *)
&nmskloctab, (size_t) (nmskidxnbr * sizeof (unsigned int)),
&nmskglbtab, (size_t) (nmskidxnbr * sizeof (unsigned int)),
&tgloloctab, (size_t) ((tgtnbr + 1) * sizeof (Gnum)), /* TRICK: "+1" to have a "-1" cell for unmapped vertices */
&tgloglbtab, (size_t) (tgtnbr * sizeof (Gnum)),
&termgsttax, (size_t) (grafptr->vertgstnbr * sizeof (Gnum)), NULL) == NULL) {
cheklocval = 1;
}
if (MPI_Allreduce (&cheklocval, &chekglbval, 1, MPI_INT, MPI_MAX, grafptr->proccomm) != MPI_SUCCESS) {
errorPrint ("SCOTCH_dgraphMapView: communication error (1)");
return (1);
}
if (chekglbval != 0) {
if (nmskloctab != NULL)
memFree (nmskloctab);
errorPrint ("SCOTCH_dgraphMapView: out of memory");
return (1);
}
if (dmapTerm (&mappptr->m, grafptr, termgsttax) != 0) {
errorPrint ("SCOTCH_dgraphMapView: cannot build local terminal array");
memFree (nmskloctab);
return (1);
}
dgraphHaloAsync (grafptr, termgsttax, GNUM_MPI, &requdat);
termgsttax -= grafptr->baseval;
memSet (tgloloctab, 0, (tgtnbr + 1) * sizeof (Gnum));
tgloloctab ++; /* TRICK: trim array for "-1" cell */
veloval = 1;
for (vertlocnum = grafptr->baseval; vertlocnum < grafptr->vertlocnnd; vertlocnum ++) {
#ifdef SCOTCH_DEBUG_DMAP2
if ((termgsttax[vertlocnum] < -1) || (termgsttax[vertlocnum] >= tgtnbr)) {
errorPrint ("SCOTCH_dgraphMapView: invalid local terminal array");
memFree (nmskloctab); /* Free group leader */
return (1);
}
#endif /* SCOTCH_DEBUG_DMAP2 */
if (grafptr->veloloctax != NULL)
veloval = grafptr->veloloctax[vertlocnum];
tgloloctab[termgsttax[vertlocnum]] += veloval; /* One more vertex of given weight assigned to this target */
}
if (MPI_Allreduce (tgloloctab, tgloglbtab, tgtnbr, GNUM_MPI, MPI_SUM, grafptr->proccomm) != MPI_SUCCESS) {
errorPrint ("SCOTCH_dgraphMapView: communication error (2)");
memFree (nmskloctab); /* Free group leader */
return (1);
}
mapmin = GNUMMAX;
mapmax = 0;
mapsum = 0;
mapnbr = 0;
for (tgtnum = 0; tgtnum < tgtnbr; tgtnum ++) {
Gnum tgtsum;
tgtsum = tgloglbtab[tgtnum];
if (tgtsum != 0) {
mapnbr ++;
mapsum += tgtsum;
if (tgtsum < mapmin)
mapmin = tgtsum;
if (tgtsum > mapmax)
mapmax = tgtsum;
}
}
mapavg = (mapnbr == 0) ? 0.0L : ((double) mapsum / (double) mapnbr);
mapdlt = 0.0L;
for (tgtnum = 0; tgtnum < tgtnbr; tgtnum ++)
mapdlt += fabs ((double) tgloglbtab[tgtnum] - mapavg);
mapdlt = (mapnbr != 0) ? mapdlt / ((double) mapnbr * mapavg) : 0.0L;
mapmmy = (mapnbr != 0) ? (double) mapmax / (double) mapavg : 0.0L;
if (stream != NULL) {
fprintf (stream, "M\tProcessors " GNUMSTRING "/" GNUMSTRING "(%g)\n",
(Gnum) mapnbr,
(Gnum) tgtnbr,
(double) mapnbr / (double) tgtnbr);
fprintf (stream, "M\tTarget min=" GNUMSTRING "\tmax=" GNUMSTRING "\tavg=%g\tdlt=%g\tmaxavg=%g\n",
(Gnum) mapmin,
(Gnum) mapmax,
mapavg,
mapdlt,
mapmmy);
}
if (dgraphHaloWait (&requdat) != 0) { /* Wait for ghost terminal data to be exchanged */
errorPrint ("SCOTCH_dgraphMapView: cannot complete asynchronous halo exchange");
memFree (nmskloctab); /* Free group leader */
return (1);
}
ngbmin = ANUMMAX;
ngbmax = 0;
ngbsum = 0;
for (tgtnum = 0; tgtnum < tgtnbr; tgtnum ++) { /* For all subdomain indices */
int nmskidxnum;
Gnum vertlocnum;
Anum ngbnbr;
if (tgloglbtab[tgtnum] <= 0) /* If empty subdomain, skip it */
continue;
memSet (nmskloctab, 0, nmskidxnbr * sizeof (int)); /* Reset neighbor bit mask */
for (vertlocnum = grafptr->baseval; vertlocnum < grafptr->vertlocnnd; vertlocnum ++) { /* For all local vertices */
Gnum termnum;
Gnum edgelocnum;
Gnum edgelocnnd;
termnum = termgsttax[vertlocnum];
if (termnum != tgtnum) /* If vertex does not belong to current part or is not mapped, skip it */
continue;
for (edgelocnum = grafptr->vertloctax[vertlocnum], edgelocnnd = grafptr->vendloctax[vertlocnum];
edgelocnum < edgelocnnd; edgelocnum ++) {
Gnum termend;
termend = termgsttax[grafptr->edgegsttax[edgelocnum]];
if (termend != tgtnum) { /* If edge is not internal */
termend ++; /* TRICK: turn unmapped to 0 and so on */
nmskloctab[termend / (sizeof (int) << 3)] |= 1 << (termend & ((sizeof (int) << 3) - 1)); /* Flag neighbor in bit array */
}
}
}
nmskloctab[0] &= ~1; /* Do not account for unmapped vertices (terminal domain 0 because of "+1") */
if (MPI_Allreduce (nmskloctab, nmskglbtab, nmskidxnbr, MPI_INT, MPI_BOR, grafptr->proccomm) != MPI_SUCCESS) {
errorPrint ("SCOTCH_dgraphMapView: communication error (3)");
memFree (nmskloctab); /* Free group leader */
return (1);
}
for (nmskidxnum = 0, ngbnbr = 0; nmskidxnum < nmskidxnbr; nmskidxnum ++) {
unsigned int nmskbitval;
for (nmskbitval = nmskglbtab[nmskidxnum]; nmskbitval != 0; nmskbitval >>= 1)
ngbnbr += nmskbitval & 1;
}
ngbsum += ngbnbr;
if (ngbnbr < ngbmin)
ngbmin = ngbnbr;
if (ngbnbr > ngbmax)
ngbmax = ngbnbr;
}
if (stream != NULL) {
fprintf (stream, "M\tNeighbors min=" GNUMSTRING "\tmax=" GNUMSTRING "\tsum=" GNUMSTRING "\n",
(Gnum) ngbmin,
(Gnum) ngbmax,
(Gnum) ngbsum);
}
memSet (commlocdist, 0, 256 * sizeof (Gnum)); /* Initialize the data */
commlocload =
commlocdilat =
commlocexpan = 0;
edloval = 1;
for (vertlocnum = grafptr->baseval; vertlocnum < grafptr->vertlocnnd; vertlocnum ++) { /* For all local vertices */
Gnum termlocnum;
ArchDom termdomdat;
Gnum edgelocnum;
Gnum edgelocnnd;
termlocnum = termgsttax[vertlocnum];
if (termlocnum == ~0) /* Skip unmapped vertices */
continue;
archDomTerm (&mappptr->m.archdat, &termdomdat, termlocnum);
for (edgelocnum = grafptr->vertloctax[vertlocnum], edgelocnnd = grafptr->vendloctax[vertlocnum];
edgelocnum < edgelocnnd; edgelocnum ++) {
ArchDom termdomend;
Gnum termgstend;
Anum distval;
termgstend = termgsttax[grafptr->edgegsttax[edgelocnum]];
if (termgstend == ~0) /* Skip unmapped end vertices */
continue;
distval = 0;
if (grafptr->edloloctax != NULL) /* Get edge weight if any */
edloval = grafptr->edloloctax[edgelocnum];
if (termgstend != termlocnum) { /* If not same domain, compute distance */
archDomTerm (&mappptr->m.archdat, &termdomend, termgstend);
distval = archDomDist (&mappptr->m.archdat, &termdomdat, &termdomend);
}
commlocdist[(distval > 255) ? 255 : distval] += edloval;
commlocload += edloval;
commlocdilat += distval;
commlocexpan += distval * edloval;
}
}
commlocdist[256] = commlocload;
commlocdist[256 + 1] = commlocdilat;
commlocdist[256 + 2] = commlocexpan;
if (MPI_Allreduce (commlocdist, commglbdist, 256 + 3, GNUM_MPI, MPI_SUM, grafptr->proccomm) != MPI_SUCCESS) {
errorPrint ("SCOTCH_dgraphMapView: communication error (4)");
memFree (nmskloctab); /* Free group leader */
return (1);
}
if (stream != NULL) {
Gnum commglbload;
commglbload = commglbdist[256];
fprintf (stream, "M\tCommDilat=%f\t(" GNUMSTRING ")\n", /* Print expansion parameters */
(double) commglbdist[256 + 1] / grafptr->edgeglbnbr,
(Gnum) (commglbdist[256 + 1] / 2));
fprintf (stream, "M\tCommExpan=%f\t(" GNUMSTRING ")\n",
((commglbload == 0) ? (double) 0.0L
: (double) commglbdist[256 + 2] / (double) commglbload),
(Gnum) (commglbdist[256 + 2] / 2));
fprintf (stream, "M\tCommCutSz=%f\t(" GNUMSTRING ")\n",
((commglbload == 0) ? (double) 0.0L
: (double) (commglbload - commglbdist[0]) / (double) commglbload),
(Gnum) ((commglbload - commglbdist[0]) / 2));
fprintf (stream, "M\tCommDelta=%f\n",
(((double) commglbload * (double) commglbdist[256 + 1]) == 0.0L)
? (double) 0.0L
: ((double) commglbdist[256 + 2] * (double) grafptr->edgeglbnbr) /
((double) commglbload * (double) commglbdist[256 + 2]));
for (distmax = 255; distmax != -1; distmax --) /* Find longest distance */
if (commglbdist[distmax] != 0)
break;
for (distval = 0; distval <= distmax; distval ++) /* Print distance histogram */
fprintf (stream, "M\tCommLoad[" ANUMSTRING "]=%f\n",
(Anum) distval,
(double) commglbdist[distval] / (double) commglbload);
}
memFree (nmskloctab); /* Free group leader */
return (0);
}
** It returns:
** - 0 : if the coarse graph has been built.
** - 1 : if threshold achieved or on error.
*/
static
int
kgraphMapMlCoarsen (
const Kgraph * restrict const finegrafptr, /*+ Finer graph +*/
Kgraph * restrict const coargrafptr, /*+ Coarser graph to build +*/
GraphCoarsenMulti * restrict * const coarmultptr, /*+ Pointer to multinode table to build +*/
const KgraphMapMlParam * const paraptr) /*+ Method parameters +*/
{
Gnum vertmax;
vertmax = (archVar (&finegrafptr->m.archdat) ? 1 : finegrafptr->m.domnnbr) * paraptr->coarnbr;
if (graphCoarsen (&finegrafptr->s, &coargrafptr->s, coarmultptr, vertmax,
paraptr->coarrat, paraptr->coartype) != 0)
return (1); /* Return if coarsening failed */
coargrafptr->m.baseval = finegrafptr->m.baseval;
coargrafptr->m.vertnbr = coargrafptr->s.vertnbr;
coargrafptr->m.parttax = NULL; /* Do not allocate part array yet */
coargrafptr->m.domntab = finegrafptr->m.domntab; /* Re-use domain array */
coargrafptr->m.domnnbr = finegrafptr->m.domnnbr;
coargrafptr->m.domnmax = finegrafptr->m.domnmax;
coargrafptr->m.archdat = finegrafptr->m.archdat;
coargrafptr->m.domnorg = finegrafptr->m.domnorg;
coargrafptr->frontab = finegrafptr->frontab; /* Re-use frontier array if it exists */
coargrafptr->comploadavg = finegrafptr->comploadavg; /* Re-use existing load arrays */