/*************************************************************************
* This function is the entry point of the initial partitioning algorithm.
* This algorithm assembles the graph to all the processors and preceed
* serially.
**************************************************************************/
idx_t Mc_Diffusion(ctrl_t *ctrl, graph_t *graph, idx_t *vtxdist, idx_t *where,
idx_t *home, idx_t npasses)
{
idx_t h, i, j;
idx_t nvtxs, nedges, ncon, pass, iter, domain, processor;
idx_t nparts, mype, npes, nlinks, me, you, wsize;
idx_t nvisited, nswaps = -1, tnswaps, done, alldone = -1;
idx_t *rowptr, *colind, *diff_where, *sr_where, *ehome, *map, *rmap;
idx_t *pack, *unpack, *match, *proc2sub, *sub2proc;
idx_t *visited, *gvisited;
real_t *transfer, *npwgts, maxdiff, minflow, maxflow;
real_t lbavg, oldlbavg, ubavg, *lbvec;
real_t *diff_flows, *sr_flows;
real_t diff_lbavg, sr_lbavg, diff_cost, sr_cost;
idx_t *rbuffer, *sbuffer;
idx_t *rcount, *rdispl;
real_t *solution, *load, *workspace;
matrix_t matrix;
graph_t *egraph;
if (graph->ncon > 3)
return 0;
WCOREPUSH;
nvtxs = graph->nvtxs;
nedges = graph->nedges;
ncon = graph->ncon;
nparts = ctrl->nparts;
mype = ctrl->mype;
npes = ctrl->npes;
ubavg = ravg(ncon, ctrl->ubvec);
/* initialize variables and allocate memory */
lbvec = rwspacemalloc(ctrl, ncon);
diff_flows = rwspacemalloc(ctrl, ncon);
sr_flows = rwspacemalloc(ctrl, ncon);
load = rwspacemalloc(ctrl, nparts);
solution = rwspacemalloc(ctrl, nparts);
npwgts = graph->gnpwgts = rwspacemalloc(ctrl, ncon*nparts);
matrix.values = rwspacemalloc(ctrl, nedges);
transfer = matrix.transfer = rwspacemalloc(ctrl, ncon*nedges);
proc2sub = iwspacemalloc(ctrl, gk_max(nparts, npes*2));
sub2proc = iwspacemalloc(ctrl, nparts);
match = iwspacemalloc(ctrl, nparts);
rowptr = matrix.rowptr = iwspacemalloc(ctrl, nparts+1);
colind = matrix.colind = iwspacemalloc(ctrl, nedges);
rcount = iwspacemalloc(ctrl, npes);
rdispl = iwspacemalloc(ctrl, npes+1);
pack = iwspacemalloc(ctrl, nvtxs);
unpack = iwspacemalloc(ctrl, nvtxs);
rbuffer = iwspacemalloc(ctrl, nvtxs);
sbuffer = iwspacemalloc(ctrl, nvtxs);
map = iwspacemalloc(ctrl, nvtxs);
rmap = iwspacemalloc(ctrl, nvtxs);
diff_where = iwspacemalloc(ctrl, nvtxs);
ehome = iwspacemalloc(ctrl, nvtxs);
wsize = gk_max(sizeof(real_t)*nparts*6, sizeof(idx_t)*(nvtxs+nparts*2+1));
workspace = (real_t *)gk_malloc(wsize, "Mc_Diffusion: workspace");
graph->ckrinfo = (ckrinfo_t *)gk_malloc(nvtxs*sizeof(ckrinfo_t), "Mc_Diffusion: rinfo");
/* construct subdomain connectivity graph */
matrix.nrows = nparts;
SetUpConnectGraph(graph, &matrix, (idx_t *)workspace);
nlinks = (matrix.nnzs-nparts) / 2;
visited = iwspacemalloc(ctrl, matrix.nnzs);
gvisited = iwspacemalloc(ctrl, matrix.nnzs);
for (pass=0; pass<npasses; pass++) {
rset(matrix.nnzs*ncon, 0.0, transfer);
iset(matrix.nnzs, 0, gvisited);
iset(matrix.nnzs, 0, visited);
iter = nvisited = 0;
/* compute ncon flow solutions */
for (h=0; h<ncon; h++) {
rset(nparts, 0.0, solution);
ComputeLoad(graph, nparts, load, ctrl->tpwgts, h);
lbvec[h] = (rmax(nparts, load)+1.0/nparts) * (real_t)nparts;
ConjGrad2(&matrix, load, solution, 0.001, workspace);
ComputeTransferVector(ncon, &matrix, solution, transfer, h);
}
oldlbavg = ravg(ncon, lbvec);
tnswaps = 0;
maxdiff = 0.0;
for (i=0; i<nparts; i++) {
for (j=rowptr[i]; j<rowptr[i+1]; j++) {
maxflow = rmax(ncon, transfer+j*ncon);
minflow = rmin(ncon, transfer+j*ncon);
maxdiff = (maxflow - minflow > maxdiff) ? maxflow - minflow : maxdiff;
}
}
while (nvisited < nlinks) {
/* compute independent sets of subdomains */
iset(gk_max(nparts, npes*2), UNMATCHED, proc2sub);
CSR_Match_SHEM(&matrix, match, proc2sub, gvisited, ncon);
/* set up the packing arrays */
iset(nparts, UNMATCHED, sub2proc);
for (i=0; i<npes*2; i++) {
if (proc2sub[i] == UNMATCHED)
break;
sub2proc[proc2sub[i]] = i/2;
}
iset(npes, 0, rcount);
for (i=0; i<nvtxs; i++) {
domain = where[i];
processor = sub2proc[domain];
if (processor != UNMATCHED)
rcount[processor]++;
}
rdispl[0] = 0;
for (i=1; i<npes+1; i++)
rdispl[i] = rdispl[i-1] + rcount[i-1];
iset(nvtxs, UNMATCHED, unpack);
for (i=0; i<nvtxs; i++) {
domain = where[i];
processor = sub2proc[domain];
if (processor != UNMATCHED)
unpack[rdispl[processor]++] = i;
}
SHIFTCSR(i, npes, rdispl);
iset(nvtxs, UNMATCHED, pack);
for (i=0; i<rdispl[npes]; i++) {
ASSERT(unpack[i] != UNMATCHED);
domain = where[unpack[i]];
processor = sub2proc[domain];
if (processor != UNMATCHED)
pack[unpack[i]] = i;
}
/* Compute the flows */
if (proc2sub[mype*2] != UNMATCHED) {
me = proc2sub[2*mype];
you = proc2sub[2*mype+1];
ASSERT(me != you);
for (j=rowptr[me]; j<rowptr[me+1]; j++) {
if (colind[j] == you) {
visited[j] = 1;
rcopy(ncon, transfer+j*ncon, diff_flows);
break;
}
}
for (j=rowptr[you]; j<rowptr[you+1]; j++) {
if (colind[j] == me) {
visited[j] = 1;
for (h=0; h<ncon; h++) {
if (transfer[j*ncon+h] > 0.0)
diff_flows[h] = -1.0 * transfer[j*ncon+h];
}
break;
}
}
nswaps = 1;
rcopy(ncon, diff_flows, sr_flows);
iset(nvtxs, 0, sbuffer);
for (i=0; i<nvtxs; i++) {
if (where[i] == me || where[i] == you)
sbuffer[i] = 1;
}
egraph = ExtractGraph(ctrl, graph, sbuffer, map, rmap);
if (egraph != NULL) {
icopy(egraph->nvtxs, egraph->where, diff_where);
for (j=0; j<egraph->nvtxs; j++)
ehome[j] = home[map[j]];
RedoMyLink(ctrl, egraph, ehome, me, you, sr_flows, &sr_cost, &sr_lbavg);
if (ncon <= 4) {
sr_where = egraph->where;
egraph->where = diff_where;
nswaps = BalanceMyLink(ctrl, egraph, ehome, me, you, diff_flows, maxdiff,
&diff_cost, &diff_lbavg, 1.0/(real_t)nvtxs);
if ((sr_lbavg < diff_lbavg &&
(diff_lbavg >= ubavg-1.0 || sr_cost == diff_cost)) ||
(sr_lbavg < ubavg-1.0 && sr_cost < diff_cost)) {
for (i=0; i<egraph->nvtxs; i++)
where[map[i]] = sr_where[i];
}
else {
for (i=0; i<egraph->nvtxs; i++)
where[map[i]] = diff_where[i];
}
}
else {
for (i=0; i<egraph->nvtxs; i++)
where[map[i]] = egraph->where[i];
}
gk_free((void **)&egraph->xadj, &egraph->nvwgt, &egraph->adjncy, &egraph, LTERM);
}
/* Pack the flow data */
iset(nvtxs, UNMATCHED, sbuffer);
for (i=0; i<nvtxs; i++) {
domain = where[i];
if (domain == you || domain == me)
sbuffer[pack[i]] = where[i];
}
}
/* Broadcast the flow data */
gkMPI_Allgatherv((void *)&sbuffer[rdispl[mype]], rcount[mype], IDX_T,
(void *)rbuffer, rcount, rdispl, IDX_T, ctrl->comm);
/* Unpack the flow data */
for (i=0; i<rdispl[npes]; i++) {
if (rbuffer[i] != UNMATCHED)
where[unpack[i]] = rbuffer[i];
}
/* Do other stuff */
gkMPI_Allreduce((void *)visited, (void *)gvisited, matrix.nnzs,
IDX_T, MPI_MAX, ctrl->comm);
nvisited = isum(matrix.nnzs, gvisited, 1)/2;
tnswaps += GlobalSESum(ctrl, nswaps);
if (iter++ == NGD_PASSES)
break;
}
/* perform serial refinement */
Mc_ComputeSerialPartitionParams(ctrl, graph, nparts);
Mc_SerialKWayAdaptRefine(ctrl, graph, nparts, home, ctrl->ubvec, 10);
/* check for early breakout */
for (h=0; h<ncon; h++) {
lbvec[h] = (real_t)(nparts) *
npwgts[rargmax_strd(nparts,npwgts+h,ncon)*ncon+h];
}
lbavg = ravg(ncon, lbvec);
done = 0;
if (tnswaps == 0 || lbavg >= oldlbavg || lbavg <= ubavg + 0.035)
done = 1;
alldone = GlobalSEMax(ctrl, done);
if (alldone == 1)
break;
}
/* ensure that all subdomains have at least one vertex */
/*
iset(nparts, 0, match);
for (i=0; i<nvtxs; i++)
match[where[i]]++;
done = 0;
while (done == 0) {
done = 1;
me = iargmin(nparts, match);
if (match[me] == 0) {
if (ctrl->mype == PE) printf("WARNING: empty subdomain %"PRIDX" in Mc_Diffusion\n", me);
you = iargmax(nparts, match);
for (i=0; i<nvtxs; i++) {
if (where[i] == you) {
where[i] = me;
match[you]--;
match[me]++;
done = 0;
break;
}
}
}
}
*/
/* now free memory and return */
gk_free((void **)&workspace, (void **)&graph->ckrinfo, LTERM);
graph->gnpwgts = NULL;
graph->ckrinfo = NULL;
WCOREPOP;
return 0;
}
void Adaptive_Partition(ctrl_t *ctrl, graph_t *graph)
{
idx_t i;
idx_t tewgt, tvsize;
real_t gtewgt, gtvsize;
real_t ubavg, lbavg, *lbvec;
WCOREPUSH;
lbvec = rwspacemalloc(ctrl, graph->ncon);
/************************************/
/* Set up important data structures */
/************************************/
CommSetup(ctrl, graph);
ubavg = ravg(graph->ncon, ctrl->ubvec);
tewgt = isum(graph->nedges, graph->adjwgt, 1);
tvsize = isum(graph->nvtxs, graph->vsize, 1);
gtewgt = (real_t) GlobalSESum(ctrl, tewgt) + 1.0/graph->gnvtxs; /* The +1/graph->gnvtxs were added to remove any FPE */
gtvsize = (real_t) GlobalSESum(ctrl, tvsize) + 1.0/graph->gnvtxs;
ctrl->redist_factor = ctrl->redist_base * ((gtewgt/gtvsize)/ ctrl->edge_size_ratio);
IFSET(ctrl->dbglvl, DBG_PROGRESS, rprintf(ctrl, "[%6"PRIDX" %8"PRIDX" %5"PRIDX" %5"PRIDX"][%"PRIDX"]\n",
graph->gnvtxs, GlobalSESum(ctrl, graph->nedges), GlobalSEMin(ctrl, graph->nvtxs), GlobalSEMax(ctrl, graph->nvtxs), ctrl->CoarsenTo));
if (graph->gnvtxs < 1.3*ctrl->CoarsenTo ||
(graph->finer != NULL && graph->gnvtxs > graph->finer->gnvtxs*COARSEN_FRACTION)) {
AllocateRefinementWorkSpace(ctrl, 2*graph->nedges);
/***********************************************/
/* Balance the partition on the coarsest graph */
/***********************************************/
graph->where = ismalloc(graph->nvtxs+graph->nrecv, -1, "graph->where");
icopy(graph->nvtxs, graph->home, graph->where);
ComputeParallelBalance(ctrl, graph, graph->where, lbvec);
lbavg = ravg(graph->ncon, lbvec);
if (lbavg > ubavg + 0.035 && ctrl->partType != REFINE_PARTITION)
Balance_Partition(ctrl, graph);
if (ctrl->dbglvl&DBG_PROGRESS) {
ComputePartitionParams(ctrl, graph);
ComputeParallelBalance(ctrl, graph, graph->where, lbvec);
rprintf(ctrl, "nvtxs: %10"PRIDX", cut: %8"PRIDX", balance: ",
graph->gnvtxs, graph->mincut);
for (i=0; i<graph->ncon; i++)
rprintf(ctrl, "%.3"PRREAL" ", lbvec[i]);
rprintf(ctrl, "\n");
/* free memory allocated by ComputePartitionParams */
gk_free((void **)&graph->ckrinfo, &graph->lnpwgts, &graph->gnpwgts, LTERM);
}
/* check if no coarsening took place */
if (graph->finer == NULL) {
ComputePartitionParams(ctrl, graph);
KWayBalance(ctrl, graph, graph->ncon);
KWayAdaptiveRefine(ctrl, graph, NGR_PASSES);
}
}
else {
/*******************************/
/* Coarsen it and partition it */
/*******************************/
switch (ctrl->ps_relation) {
case PARMETIS_PSR_COUPLED:
Match_Local(ctrl, graph);
break;
case PARMETIS_PSR_UNCOUPLED:
default:
Match_Global(ctrl, graph);
break;
}
Adaptive_Partition(ctrl, graph->coarser);
/********************************/
/* project partition and refine */
/********************************/
ProjectPartition(ctrl, graph);
ComputePartitionParams(ctrl, graph);
if (graph->ncon > 1 && graph->level < 4) {
ComputeParallelBalance(ctrl, graph, graph->where, lbvec);
lbavg = ravg(graph->ncon, lbvec);
if (lbavg > ubavg + 0.025) {
KWayBalance(ctrl, graph, graph->ncon);
}
}
KWayAdaptiveRefine(ctrl, graph, NGR_PASSES);
if (ctrl->dbglvl&DBG_PROGRESS) {
ComputeParallelBalance(ctrl, graph, graph->where, lbvec);
rprintf(ctrl, "nvtxs: %10"PRIDX", cut: %8"PRIDX", balance: ",
graph->gnvtxs, graph->mincut);
for (i=0; i<graph->ncon; i++)
rprintf(ctrl, "%.3"PRREAL" ", lbvec[i]);
rprintf(ctrl, "\n");
}
}
WCOREPOP;
}
/*************************************************************************
* This function performs an edge-based FM refinement
**************************************************************************/
void RedoMyLink(ctrl_t *ctrl, graph_t *graph, idx_t *home, idx_t me,
idx_t you, real_t *flows, real_t *sr_cost, real_t *sr_lbavg)
{
idx_t h, i, r;
idx_t nvtxs, nedges, ncon;
idx_t pass, lastseed, totalv;
idx_t *xadj, *adjncy, *adjwgt, *where, *vsize;
idx_t *costwhere, *lbwhere, *selectwhere;
idx_t *ed, *id, *bndptr, *bndind, *perm;
real_t *nvwgt, mycost;
real_t lbavg, *lbvec;
real_t best_lbavg, other_lbavg = -1.0, bestcost, othercost = -1.0;
real_t *npwgts, *pwgts, *tpwgts;
real_t ipc_factor, redist_factor, ftmp;
idx_t mype;
gkMPI_Comm_rank(MPI_COMM_WORLD, &mype);
WCOREPUSH;
nvtxs = graph->nvtxs;
nedges = graph->nedges;
ncon = graph->ncon;
xadj = graph->xadj;
nvwgt = graph->nvwgt;
vsize = graph->vsize;
adjncy = graph->adjncy;
adjwgt = graph->adjwgt;
where = graph->where;
ipc_factor = ctrl->ipc_factor;
redist_factor = ctrl->redist_factor;
/* set up data structures */
id = graph->sendind = iwspacemalloc(ctrl, nvtxs);
ed = graph->recvind = iwspacemalloc(ctrl, nvtxs);
bndptr = graph->sendptr = iwspacemalloc(ctrl, nvtxs);
bndind = graph->recvptr = iwspacemalloc(ctrl, nvtxs);
costwhere = iwspacemalloc(ctrl, nvtxs);
lbwhere = iwspacemalloc(ctrl, nvtxs);
perm = iwspacemalloc(ctrl, nvtxs);
lbvec = rwspacemalloc(ctrl, ncon);
pwgts = rset(2*ncon, 0.0, rwspacemalloc(ctrl, 2*ncon));
npwgts = rwspacemalloc(ctrl, 2*ncon);
tpwgts = rwspacemalloc(ctrl, 2*ncon);
graph->gnpwgts = npwgts;
RandomPermute(nvtxs, perm, 1);
icopy(nvtxs, where, costwhere);
icopy(nvtxs, where, lbwhere);
/* compute target pwgts */
for (h=0; h<ncon; h++) {
tpwgts[h] = -1.0*flows[h];
tpwgts[ncon+h] = flows[h];
}
for (i=0; i<nvtxs; i++) {
if (where[i] == me) {
for (h=0; h<ncon; h++) {
tpwgts[h] += nvwgt[i*ncon+h];
pwgts[h] += nvwgt[i*ncon+h];
}
}
else {
ASSERT(where[i] == you);
for (h=0; h<ncon; h++) {
tpwgts[ncon+h] += nvwgt[i*ncon+h];
pwgts[ncon+h] += nvwgt[i*ncon+h];
}
}
}
/* we don't want any weights to be less than zero */
for (h=0; h<ncon; h++) {
if (tpwgts[h] < 0.0) {
tpwgts[ncon+h] += tpwgts[h];
tpwgts[h] = 0.0;
}
if (tpwgts[ncon+h] < 0.0) {
tpwgts[h] += tpwgts[ncon+h];
tpwgts[ncon+h] = 0.0;
}
}
/* now compute new bisection */
bestcost = (real_t)isum(nedges, adjwgt, 1)*ipc_factor +
(real_t)isum(nvtxs, vsize, 1)*redist_factor;
best_lbavg = 10.0;
lastseed = 0;
for (pass=N_MOC_REDO_PASSES; pass>0; pass--) {
iset(nvtxs, 1, where);
/* find seed vertices */
r = perm[lastseed] % nvtxs;
lastseed = (lastseed+1) % nvtxs;
where[r] = 0;
Mc_Serial_Compute2WayPartitionParams(ctrl, graph);
Mc_Serial_Init2WayBalance(ctrl, graph, tpwgts);
Mc_Serial_FM_2WayRefine(ctrl, graph, tpwgts, 4);
Mc_Serial_Balance2Way(ctrl, graph, tpwgts, 1.02);
Mc_Serial_FM_2WayRefine(ctrl, graph, tpwgts, 4);
for (i=0; i<nvtxs; i++)
where[i] = (where[i] == 0) ? me : you;
for (i=0; i<ncon; i++) {
ftmp = (pwgts[i]+pwgts[ncon+i])/2.0;
if (ftmp != 0.0)
lbvec[i] = fabs(npwgts[i]-tpwgts[i])/ftmp;
else
lbvec[i] = 0.0;
}
lbavg = ravg(ncon, lbvec);
totalv = 0;
for (i=0; i<nvtxs; i++)
if (where[i] != home[i])
totalv += vsize[i];
mycost = (real_t)(graph->mincut)*ipc_factor + (real_t)totalv*redist_factor;
if (bestcost >= mycost) {
bestcost = mycost;
other_lbavg = lbavg;
icopy(nvtxs, where, costwhere);
}
if (best_lbavg >= lbavg) {
best_lbavg = lbavg;
othercost = mycost;
icopy(nvtxs, where, lbwhere);
}
}
if (other_lbavg <= .05) {
selectwhere = costwhere;
*sr_cost = bestcost;
*sr_lbavg = other_lbavg;
}
else {
selectwhere = lbwhere;
*sr_cost = othercost;
*sr_lbavg = best_lbavg;
}
icopy(nvtxs, selectwhere, where);
WCOREPOP;
}
