/* Fix the order of the panels to be taken. */
void
Preorder(const int pnum, const int n, const int *etree, int *cur_pan,
queue_t *taskq, int *fb_cols, int *bcol,
pxgstrf_shared_t *pxgstrf_shared)
{
register int w, dad, dad_ukids;
#undef POSTORDER
#ifdef POSTORDER
if ( *cur_pan == EMPTY ) {
*cur_pan = 0;
} else {
w = pxgstrf_shared->pan_status[*cur_pan].size;
*cur_pan += w;
}
#else /* Breadth-first bottom up */
if ( *cur_pan != EMPTY ) {
dad = DADPANEL (*cur_pan);
dad_ukids = --pxgstrf_shared->pan_status[dad].ukids;
if ( dad_ukids == 0 ) {
taskq->queue[taskq->tail++] = dad;
++taskq->count;
}
}
*cur_pan = taskq->queue[taskq->head++];
--taskq->count;
#endif
--pxgstrf_shared->tasks_remain;
*bcol = *cur_pan;
}
void
pxgstrf_scheduler(const int pnum, const int n, const int *etree,
int *cur_pan, int *bcol, pxgstrf_shared_t *pxgstrf_shared)
{
/*
* -- SuperLU MT routine (version 1.0) --
* Univ. of California Berkeley, Xerox Palo Alto Research Center,
* and Lawrence Berkeley National Lab.
* August 15, 1997
*
* Purpose
* =======
*
* pxgstrf_scheduler() gets a panel for the processor to work on.
* It schedules a panel in decreasing order of priority:
* (1) the current panel's parent, if it can be done without pipelining
* (2) any other panel in the queue that can be done without pipelining
* ("CANGO" status)
* (3) any other panel in the queue that can be done with pipelining
* ("CANPIPE" status)
*
* Arguments
* =========
* pnum (input) int
* Processor number.
*
* n (input) int
* Column dimension of the matrix.
*
* etree (input) int*
* Elimination tree of A'*A, size n.
* Note: etree is a vector of parent pointers for a forest whose
* vertices are the integers 0 to n-1; etree[root] = n.
*
* cur_pan (input/output) int*
* On entry, the current panel just finished by this processor;
* On exit, [0, n-1]: the new panel to work on;
* EMPTY: failed to get any work, will try later;
* n: all panels are taken; ready to terminate.
*
* taskq (input/output) queue_t*
* Global work queue.
*
* fb_cols (input/output) int*
* The farthest busy descendant of each (leading column of the) panel.
*
* bcol (output) int*
* The most distant busy descendant of cur_pan in the *linear*
* pipeline of busy descendants. If all proper descendants of
* cur_pan are done, bcol is returned equal to cur_pan.
*
* Defining terms
* ==============
* o parent(panel) = etree(last column in the panel)
* o the kids of a panel = collective kids of all columns in the panel
* kids[REP] = SUM_{j in panel} ( kids[j] )
* o linear pipeline - what does it mean in the panel context?
* if ukids[REP] = 0, then the panel becomes a leaf (CANGO)
* if ukids[REP] = 1 && ukids[firstcol] = 1, then the panel can
* be taken with pipelining (CANPIPE)
*
* NOTES
* =====
* o When a "busy" panel finishes, if its parent has only one remaining
* undone child there is no check to see if the parent should change
* from "unready" to "canpipe". Thus a few potential pipelinings will
* be lost, but checking out this pipeline opportunity may be costly.
*
*/
register int dad, dad_ukids, jcol, w, j;
int *fb_cols = pxgstrf_shared->fb_cols;
queue_t *taskq = &pxgstrf_shared->taskq;
Gstat_t *Gstat = pxgstrf_shared->Gstat;
#ifdef PROFILE
double t;
#endif
jcol = *cur_pan;
if ( jcol != EMPTY ) {
#ifdef DOMAINS
if ( in_domain[jcol] == TREE_DOMAIN )
dad = etree[jcol];
else
#endif
dad = DADPANEL (jcol);
}
/* w_top = sp_ienv(1)/2;
if ( w_top == 0 ) w_top = 1;*/
#ifdef PROFILE
TIC(t);
#endif
#if ( MACH==SUN )
mutex_lock( &pxgstrf_shared->lu_locks[SCHED_LOCK] );
#elif ( MACH==DEC || MACH==PTHREAD )
pthread_mutex_lock( &pxgstrf_shared->lu_locks[SCHED_LOCK] );
#elif ( MACH==SGI || MACH==ORIGIN )
#pragma critical lock(pxgstrf_shared->lu_locks[SCHED_LOCK])
#elif ( MACH==CRAY_PVP )
#pragma _CRI guard SCHED_LOCK
#elif ( MACH==OPENMP )
#pragma omp critical ( SCHED_LOCK )
#endif
{ /* ---- START CRITICAL SECTION ---- */
/* Update the status of the current panel and its parent, so that
* the other processors waiting on it can proceed.
* If all siblings are done, and dad is not busy, then take dad.
*/
if ( jcol != EMPTY ) { /* jcol was just finished by this processor */
dad_ukids = --pxgstrf_shared->pan_status[dad].ukids;
#ifdef DEBUG
printf("(%d) DONE %d in Scheduler(), dad %d, STATE %d, dad_ukids %d\n",
pnum, jcol, dad, STATE(dad), dad_ukids);
#endif
if ( dad_ukids == 0 && STATE( dad ) > BUSY ) { /* dad not started */
jcol = dad;
#ifdef DEBUG
printf("(%d) Scheduler[1] Got dad %d, STATE %d\n",
pnum, jcol, STATE(dad));
#endif
#ifdef PROFILE
++(Gstat->panhows[DADPAN]);
#endif
} else {
/* Try to get a panel from the task Q. */
while ( 1 ) {
/*>>if ( (j = Dequeue(taskq, &item)) == EMPTY ) {*/
if ( taskq->count <= 0 ) {
jcol = EMPTY;
break;
} else {
jcol = taskq->queue[taskq->head++];
--taskq->count;
if ( STATE( jcol ) >= CANGO ) { /* CANGO or CANPIPE */
#ifdef DEBUG
printf("(%d) Dequeue[1] Got %d, STATE %d, Qcount %d\n",
pnum, jcol, STATE(jcol), j);
#endif
#ifdef PROFILE
if (STATE( jcol ) == CANGO) ++(Gstat->panhows[NOPIPE]);
else ++(Gstat->panhows[PIPE]);
#endif
break;
}
}
} /* while */
}
} else {
/*
* jcol was EMPTY; Try to get a panel from the task Q.
*/
while ( 1 ) {
/*>>if ( (j = Dequeue(taskq, &item)) == EMPTY ) {*/
if ( taskq->count <= 0 ) {
jcol = EMPTY;
break;
} else {
jcol = taskq->queue[taskq->head++];
--taskq->count;
if ( STATE( jcol ) >= CANGO ) { /* CANGO or CANPIPE */
#ifdef DEBUG
printf("(%d) Dequeue[2] Got %d, STATE %d, Qcount %d\n",
pnum, jcol, STATE(jcol), j);
#endif
#ifdef PROFILE
if (STATE( jcol ) == CANGO) ++(Gstat->panhows[NOPIPE]);
else ++(Gstat->panhows[PIPE]);
#endif
break;
}
}
} /* while */
}
/*
* Update the status of the new panel "jcol" and its parent "dad".
*/
if ( jcol != EMPTY ) {
--pxgstrf_shared->tasks_remain;
#ifdef DOMAINS
if ( in_domain[jcol] == TREE_DOMAIN ) {
/* Dequeue the first descendant of this domain */
*bcol = taskq->queue[taskq->head++];
--taskq->count;
} else
#endif
{
STATE( jcol ) = BUSY;
w = pxgstrf_shared->pan_status[jcol].size;
for (j = jcol; j < jcol+w; ++j) pxgstrf_shared->spin_locks[j] = 1;
dad = DADPANEL (jcol);
if ( dad < n && pxgstrf_shared->pan_status[dad].ukids == 1 ) {
STATE( dad ) = CANPIPE;
/*>> j = Enqueue(taskq, dad);*/
taskq->queue[taskq->tail++] = dad;
++taskq->count;
#ifdef DEBUG
printf("(%d) Enqueue() %d's dad %d ->CANPIPE, Qcount %d\n",
pnum, jcol, dad, j);
#endif
}
#ifdef PROFILE
Gstat->procstat[pnum].panels++;
#endif
/* Find the farthest busy descendant of the new panel
and its parent.*/
*bcol = fb_cols[jcol];
#ifdef DEBUG
printf("(%d) Scheduler[2] fb_cols[%d]=%d, STATE %d\n",
pnum, jcol, *bcol, STATE( *bcol ));
#endif
while ( STATE( *bcol ) == DONE ) *bcol = DADPANEL (*bcol);
fb_cols[dad] = *bcol;
} /* else regular_panel */
} /* if jcol != empty */
*cur_pan = jcol;
#ifdef DEBUG
printf("(%d) Exit C.S. tasks_remain %d, cur_pan %d\n",
pnum, pxgstrf_shared->tasks_remain, jcol);
#endif
} /* ---- END CRITICAL SECTION ---- */
#if ( MACH==SUN )
/* Exit C.S. */
mutex_unlock( &pxgstrf_shared->lu_locks[SCHED_LOCK] );
#elif ( MACH==DEC || MACH==PTHREAD )
pthread_mutex_unlock( &pxgstrf_shared->lu_locks[SCHED_LOCK] );
#elif ( MACH==CRAY_PVP )
#pragma _CRI endguard SCHED_LOCK
#endif
#ifdef PROFILE
Gstat->procstat[pnum].cs_time += SuperLU_timer_() - t;
#endif
return;
}
