Merge branch 'subsize' into 'master'

Subsize

Use separate parameters to determine when a pair or self interaction should be made a sub-cell task.

See merge request !365

examples/parameter_example.yml

@@ -8,12 +8,12 @@ InternalUnitSystem:
 
 # Parameters for the task scheduling
 Scheduler:
-  nr_queues:             0        # (Optional) The number of task queues to use. Use 0  to let the system decide.
-  cell_max_size:         8000000  # (Optional) Maximal number of interactions per task if we force the split (this is the default value).
-  cell_sub_size:         64000000 # (Optional) Maximal number of interactions per sub-task  (this is the default value).
-  cell_split_size:       400      # (Optional) Maximal number of particles per cell (this is the default value).
-  cell_max_count:        10000    # (Optional) Maximal number of particles per cell allowed before triggering a sanitizing (this is the default value).
-  max_top_level_cells:   12       # (Optional) Maximal number of top-level cells in any dimension. The number of top-level cells will be the cube of this (this is the default value).
+  nr_queues:             0         # (Optional) The number of task queues to use. Use 0  to let the system decide.
+  cell_max_size:         8000000   # (Optional) Maximal number of interactions per task if we force the split (this is the default value).
+  cell_sub_size_pair:    256000000 # (Optional) Maximal number of interactions per sub-pair task  (this is the default value).
+  cell_sub_size_self:    32000     # (Optional) Maximal number of interactions per sub-self task  (this is the default value).
+  cell_split_size:       400       # (Optional) Maximal number of particles per cell (this is the default value).
+  max_top_level_cells:   12        # (Optional) Maximal number of top-level cells in any dimension. The number of top-level cells will be the cube of this (this is the default value).
 
 # Parameters governing the time integration (Set dt_min and dt_max to the same value for a fixed time-step run.)
 TimeIntegration:

src/scheduler.c

@@ -151,8 +151,7 @@ static void scheduler_splittask_hydro(struct task *t, struct scheduler *s) {
       if (cell_can_split_self_task(ci)) {
 
         /* Make a sub? */
-        if (scheduler_dosub && /* Note division here to avoid overflow */
-            (ci->count > 0 && ci->count < space_subsize / ci->count)) {
+        if (scheduler_dosub && ci->count < space_subsize_self) {
 
           /* convert to a self-subtask. */
           t->type = task_type_sub_self;
@@ -211,8 +210,8 @@ static void scheduler_splittask_hydro(struct task *t, struct scheduler *s) {
       if (cell_can_split_pair_task(ci) && cell_can_split_pair_task(cj)) {
 
         /* Replace by a single sub-task? */
-        if (scheduler_dosub &&
-            ci->count * sid_scale[sid] < space_subsize / cj->count &&
+        if (scheduler_dosub && /* Use division to avoid integer overflow. */
+            ci->count * sid_scale[sid] < space_subsize_pair / cj->count &&
             !sort_is_corner(sid)) {
 
           /* Make this task a sub task. */
@@ -624,8 +623,7 @@ static void scheduler_splittask_gravity(struct task *t, struct scheduler *s) {
       if (ci->split) {
 
         /* Make a sub? */
-        if (scheduler_dosub && /* Note division here to avoid overflow */
-            (ci->gcount > 0 && ci->gcount < space_subsize / ci->gcount)) {
+        if (scheduler_dosub && ci->gcount < space_subsize_self) {
 
           /* convert to a self-subtask. */
           t->type = task_type_sub_self;

src/space.c

@@ -60,9 +60,9 @@
 
 /* Split size. */
 int space_splitsize = space_splitsize_default;
-int space_subsize = space_subsize_default;
+int space_subsize_pair = space_subsize_pair_default;
+int space_subsize_self = space_subsize_self_default;
 int space_maxsize = space_maxsize_default;
-int space_maxcount = space_maxcount_default;
 
 /**
  * @brief Interval stack necessary for parallel particle sorting.
@@ -2697,15 +2697,18 @@ void space_init(struct space *s, const struct swift_params *params,
   /* Get the constants for the scheduler */
   space_maxsize = parser_get_opt_param_int(params, "Scheduler:cell_max_size",
                                            space_maxsize_default);
-  space_subsize = parser_get_opt_param_int(params, "Scheduler:cell_sub_size",
-                                           space_subsize_default);
+  space_subsize_pair = parser_get_opt_param_int(
+      params, "Scheduler:cell_sub_size_pair", space_subsize_pair_default);
+  space_subsize_self = parser_get_opt_param_int(
+      params, "Scheduler:cell_sub_size_self", space_subsize_self_default);
   space_splitsize = parser_get_opt_param_int(
       params, "Scheduler:cell_split_size", space_splitsize_default);
-  space_maxcount = parser_get_opt_param_int(params, "Scheduler:cell_max_count",
-                                            space_maxcount_default);
+
   if (verbose)
-    message("max_size set to %d, sub_size set to %d, split_size set to %d",
-            space_maxsize, space_subsize, space_splitsize);
+    message(
+        "max_size set to %d, sub_size_pair set to %d, sub_size_self set to %d, "
+        "split_size set to %d",
+        space_maxsize, space_subsize_pair, space_subsize_self, space_splitsize);
 
   /* Apply h scaling */
   const double scaling =

src/space.h

@@ -43,8 +43,8 @@ struct cell;
 #define space_cellallocchunk 1000
 #define space_splitsize_default 400
 #define space_maxsize_default 8000000
-#define space_subsize_default 64000000
-#define space_maxcount_default 10000
+#define space_subsize_pair_default 256000000
+#define space_subsize_self_default 32000
 #define space_max_top_level_cells_default 12
 #define space_stretch 1.10f
 #define space_maxreldx 0.1f
@@ -55,8 +55,8 @@ struct cell;
 /* Split size. */
 extern int space_splitsize;
 extern int space_maxsize;
-extern int space_subsize;
-extern int space_maxcount;
+extern int space_subsize_pair;
+extern int space_subsize_self;
 
 /**
  * @brief The space in which the cells and particles reside.