/*
* find_resources() identifies the all of the resource candidates for
* the job. The set of resources returned could be more than the job
* requires. A later call to select_resources() will cull this list
* down to the most appropriate set for the job.
*
* Inputs: resrcs - hash table of all resources
* resrc_reqst - the resources the job requests
* Returns: nfound - the number of resources found
* found_tree - a resource tree containing resources that satisfy the
* job's request or NULL if none are found
*/
int64_t find_resources (flux_t *h, resrc_t *resrc, resrc_reqst_t *resrc_reqst,
resrc_tree_t **found_tree)
{
int64_t nfound = 0;
if (!resrc || !resrc_reqst) {
flux_log (h, LOG_ERR, "%s: invalid arguments", __FUNCTION__);
goto ret;
}
/*
* A start time of zero is used to restrict the search to now
* (appropriate for FCFS) and prevent any search into the future.
*/
if (resrc_reqst_set_starttime (resrc_reqst, 0) ||
resrc_reqst_set_endtime (resrc_reqst, 0))
goto ret;
*found_tree = NULL;
nfound = resrc_tree_search (resrc, resrc_reqst, found_tree, true);
if (!nfound && *found_tree) {
resrc_tree_destroy (*found_tree, false);
*found_tree = NULL;
}
ret:
return nfound;
}
int resrc_reqst_set_endtime (resrc_reqst_t *resrc_reqst, int64_t time)
{
if (resrc_reqst) {
resrc_reqst->endtime = time;
if (resrc_reqst_num_children (resrc_reqst)) {
resrc_reqst_t *child = resrc_reqst_list_first
(resrc_reqst->children);
while (child) {
resrc_reqst_set_endtime (child, time);
child = resrc_reqst_list_next (resrc_reqst->children);
}
}
return 0;
}
return -1;
}
/*
* select_resources() selects from the set of resource candidates the
* best resources for the job.
*
* Inputs: found_tree - tree of resource tree candidates
* resrc_reqst - the resources the job requests
* selected_parent - parent of the selected resource tree
* Returns: a resource tree of however many resources were selected
*/
resrc_tree_t *select_resources (flux_t *h, resrc_tree_t *found_tree,
resrc_reqst_t *resrc_reqst,
resrc_tree_t *selected_parent)
{
resrc_t *resrc;
resrc_tree_list_t *children = NULL;
resrc_tree_t *child_tree;
resrc_tree_t *selected_tree = NULL;
if (!resrc_reqst) {
flux_log (h, LOG_ERR, "%s: called with empty request", __FUNCTION__);
return NULL;
}
/*
* A start time of zero is used to restrict the search to now
* (appropriate for FCFS) and prevent any search into the future.
*/
if (resrc_reqst_set_starttime (resrc_reqst, 0) ||
resrc_reqst_set_endtime (resrc_reqst, 0))
return NULL;
resrc = resrc_tree_resrc (found_tree);
if (resrc_match_resource (resrc, resrc_reqst, true)) {
if (resrc_reqst_num_children (resrc_reqst)) {
if (resrc_tree_num_children (found_tree)) {
selected_tree = resrc_tree_new (selected_parent, resrc);
if (select_children (h, resrc_tree_children (found_tree),
resrc_reqst_children (resrc_reqst),
selected_tree)) {
resrc_stage_resrc (resrc,
resrc_reqst_reqrd_size (resrc_reqst),
resrc_reqst_graph_reqs (resrc_reqst));
resrc_reqst_add_found (resrc_reqst, 1);
flux_log (h, LOG_DEBUG, "selected %s", resrc_name (resrc));
} else {
resrc_tree_destroy (selected_tree, false);
}
}
} else {
selected_tree = resrc_tree_new (selected_parent, resrc);
resrc_stage_resrc (resrc, resrc_reqst_reqrd_size (resrc_reqst),
resrc_reqst_graph_reqs (resrc_reqst));
resrc_reqst_add_found (resrc_reqst, 1);
flux_log (h, LOG_DEBUG, "selected %s", resrc_name (resrc));
}
} else if (resrc_tree_num_children (found_tree)) {
/*
* This clause visits the children of the current resource
* searching for a match to the resource request. The selected
* tree must be extended to include this intermediate
* resource.
*
* This also allows the resource request to be sparsely
* defined. E.g., it might only stipulate a node with 4 cores
* and omit the intervening socket.
*/
selected_tree = resrc_tree_new (selected_parent, resrc);
children = resrc_tree_children (found_tree);
child_tree = resrc_tree_list_first (children);
while (child_tree) {
if (select_resources (h, child_tree, resrc_reqst, selected_tree) &&
resrc_reqst_nfound (resrc_reqst) >=
resrc_reqst_reqrd_qty (resrc_reqst))
break;
child_tree = resrc_tree_list_next (children);
}
}
return selected_tree;
}
/*
* reserve_resources() reserves resources for the specified job id.
* Unlike the FCFS version where selected_tree provides the tree of
* resources to reserve, this backfill version will search into the
* future to find a time window when all of the required resources are
* available, reserve those, and return the pointer to the selected
* tree.
*/
int reserve_resources (flux_t h, resrc_tree_t **selected_tree, int64_t job_id,
int64_t starttime, int64_t walltime, resrc_t *resrc,
resrc_reqst_t *resrc_reqst)
{
int rc = -1;
int64_t *completion_time = NULL;
int64_t nfound = 0;
int64_t prev_completion_time = -1;
resrc_tree_t *found_tree = NULL;
if (reservation_depth > 0 && (curr_reservation_depth >= reservation_depth)) {
goto ret;
} else if (!resrc || !resrc_reqst) {
flux_log (h, LOG_ERR, "%s: invalid arguments", __FUNCTION__);
goto ret;
}
if (*selected_tree) {
resrc_tree_destroy (*selected_tree, false);
*selected_tree = NULL;
}
zlist_sort (completion_times, compare_int64_ascending);
for (completion_time = zlist_first (completion_times);
completion_time;
completion_time = zlist_next (completion_times)) {
/* Purge past times from consideration */
if (*completion_time < starttime) {
zlist_remove (completion_times, completion_time);
continue;
}
/* Don't test the same time multiple times */
if (prev_completion_time == *completion_time)
continue;
resrc_reqst_set_starttime (resrc_reqst, *completion_time + 1);
resrc_reqst_set_endtime (resrc_reqst, *completion_time + 1 + walltime);
flux_log (h, LOG_DEBUG, "Attempting to reserve %"PRId64" nodes for job "
"%"PRId64" at time %"PRId64"",
resrc_reqst_reqrd_qty (resrc_reqst), job_id,
*completion_time + 1);
nfound = resrc_tree_search (resrc, resrc_reqst, &found_tree, true);
if (nfound >= resrc_reqst_reqrd_qty (resrc_reqst)) {
*selected_tree = select_resources (h, found_tree, resrc_reqst, NULL);
resrc_tree_destroy (found_tree, false);
if (*selected_tree) {
rc = resrc_tree_reserve (*selected_tree, job_id,
*completion_time + 1,
*completion_time + 1 + walltime);
if (rc) {
resrc_tree_destroy (*selected_tree, false);
*selected_tree = NULL;
} else {
curr_reservation_depth++;
flux_log (h, LOG_DEBUG, "Reserved %"PRId64" nodes for job "
"%"PRId64" from %"PRId64" to %"PRId64"",
resrc_reqst_reqrd_qty (resrc_reqst), job_id,
*completion_time + 1,
*completion_time + 1 + walltime);
}
break;
}
}
prev_completion_time = *completion_time;
}
ret:
return rc;
}
