Merge branch 'faster_rebuilds' into 'master'

Updated cell splitting strategy

See merge request swift/swiftsim!493

src/cell.c

@@ -835,11 +835,15 @@ void cell_split(struct cell *c, ptrdiff_t parts_offset, ptrdiff_t sparts_offset,
           memswap(&parts[j], &part, sizeof(struct part));
           memswap(&xparts[j], &xpart, sizeof(struct xpart));
           memswap(&buff[j], &temp_buff, sizeof(struct cell_buff));
+          if (parts[j].gpart)
+            parts[j].gpart->id_or_neg_offset = -(j + parts_offset);
           bid = temp_buff.ind;
         }
         parts[k] = part;
         xparts[k] = xpart;
         buff[k] = temp_buff;
+        if (parts[k].gpart)
+          parts[k].gpart->id_or_neg_offset = -(k + parts_offset);
       }
       bucket_count[bid]++;
     }
@@ -852,10 +856,6 @@ void cell_split(struct cell *c, ptrdiff_t parts_offset, ptrdiff_t sparts_offset,
     c->progeny[k]->xparts = &c->xparts[bucket_offset[k]];
   }
 
-  /* Re-link the gparts. */
-  if (count > 0 && gcount > 0)
-    part_relink_gparts_to_parts(parts, count, parts_offset);
-
 #ifdef SWIFT_DEBUG_CHECKS
   /* Check that the buffs are OK. */
   for (int k = 1; k < count; k++) {
@@ -952,10 +952,14 @@ void cell_split(struct cell *c, ptrdiff_t parts_offset, ptrdiff_t sparts_offset,
           }
           memswap(&sparts[j], &spart, sizeof(struct spart));
           memswap(&sbuff[j], &temp_buff, sizeof(struct cell_buff));
+          if (sparts[j].gpart)
+            sparts[j].gpart->id_or_neg_offset = -(j + sparts_offset);
           bid = temp_buff.ind;
         }
         sparts[k] = spart;
         sbuff[k] = temp_buff;
+        if (sparts[k].gpart)
+          sparts[k].gpart->id_or_neg_offset = -(k + sparts_offset);
       }
       bucket_count[bid]++;
     }
@@ -967,10 +971,6 @@ void cell_split(struct cell *c, ptrdiff_t parts_offset, ptrdiff_t sparts_offset,
     c->progeny[k]->sparts = &c->sparts[bucket_offset[k]];
   }
 
-  /* Re-link the gparts. */
-  if (scount > 0 && gcount > 0)
-    part_relink_gparts_to_sparts(sparts, scount, sparts_offset);
-
   /* Finally, do the same song and dance for the gparts. */
   for (int k = 0; k < 8; k++) bucket_count[k] = 0;
 
@@ -1005,10 +1005,23 @@ void cell_split(struct cell *c, ptrdiff_t parts_offset, ptrdiff_t sparts_offset,
           }
           memswap(&gparts[j], &gpart, sizeof(struct gpart));
           memswap(&gbuff[j], &temp_buff, sizeof(struct cell_buff));
+          if (gparts[j].type == swift_type_gas) {
+            parts[-gparts[j].id_or_neg_offset - parts_offset].gpart =
+                &gparts[j];
+          } else if (gparts[j].type == swift_type_star) {
+            sparts[-gparts[j].id_or_neg_offset - sparts_offset].gpart =
+                &gparts[j];
+          }
           bid = temp_buff.ind;
         }
         gparts[k] = gpart;
         gbuff[k] = temp_buff;
+        if (gparts[k].type == swift_type_gas) {
+          parts[-gparts[k].id_or_neg_offset - parts_offset].gpart = &gparts[k];
+        } else if (gparts[k].type == swift_type_star) {
+          sparts[-gparts[k].id_or_neg_offset - sparts_offset].gpart =
+              &gparts[k];
+        }
       }
       bucket_count[bid]++;
     }
@@ -1019,14 +1032,6 @@ void cell_split(struct cell *c, ptrdiff_t parts_offset, ptrdiff_t sparts_offset,
     c->progeny[k]->gcount = bucket_count[k];
     c->progeny[k]->gparts = &c->gparts[bucket_offset[k]];
   }
-
-  /* Re-link the parts. */
-  if (count > 0 && gcount > 0)
-    part_relink_parts_to_gparts(gparts, gcount, parts - parts_offset);
-
-  /* Re-link the sparts. */
-  if (scount > 0 && gcount > 0)
-    part_relink_sparts_to_gparts(gparts, gcount, sparts - sparts_offset);
 }
 
 /**

src/engine.c

@@ -565,7 +565,8 @@ void engine_redistribute(struct engine *e) {
 
   /* Sort the particles according to their cell index. */
   if (s->nr_parts > 0)
-    space_parts_sort(s, dest, s->nr_parts, 0, nr_nodes - 1, e->verbose);
+    space_parts_sort(s->parts, s->xparts, dest, &counts[nodeID * nr_nodes],
+                     nr_nodes, 0);
 
 #ifdef SWIFT_DEBUG_CHECKS
   /* Verify that the part have been sorted correctly. */
@@ -656,7 +657,8 @@ void engine_redistribute(struct engine *e) {
 
   /* Sort the particles according to their cell index. */
   if (s->nr_sparts > 0)
-    space_sparts_sort(s, s_dest, s->nr_sparts, 0, nr_nodes - 1, e->verbose);
+    space_sparts_sort(s->sparts, s_dest, &s_counts[nodeID * nr_nodes], nr_nodes,
+                      0);
 
 #ifdef SWIFT_DEBUG_CHECKS
   /* Verify that the spart have been sorted correctly. */
@@ -748,7 +750,8 @@ void engine_redistribute(struct engine *e) {
 
   /* Sort the gparticles according to their cell index. */
   if (s->nr_gparts > 0)
-    space_gparts_sort(s, g_dest, s->nr_gparts, 0, nr_nodes - 1, e->verbose);
+    space_gparts_sort(s->gparts, s->parts, s->sparts, g_dest,
+                      &g_counts[nodeID * nr_nodes], nr_nodes);
 
 #ifdef SWIFT_DEBUG_CHECKS
   /* Verify that the gpart have been sorted correctly. */
@@ -3678,6 +3681,11 @@ void engine_rebuild(struct engine *e, int clean_smoothing_length_values) {
   /* Re-build the space. */
   space_rebuild(e->s, e->verbose);
 
+#ifdef SWIFT_DEBUG_CHECKS
+  part_verify_links(e->s->parts, e->s->gparts, e->s->sparts, e->s->nr_parts,
+                    e->s->nr_gparts, e->s->nr_sparts, e->verbose);
+#endif
+
   /* Initial cleaning up session ? */
   if (clean_smoothing_length_values) space_sanitize(e->s);
 
@@ -4151,7 +4159,7 @@ void engine_first_init_particles(struct engine *e) {
 
   const ticks tic = getticks();
 
-  /* Set the particles in a state where they are ready for a run */
+  /* Set the particles in a state where they are ready for a run. */
   space_first_init_parts(e->s, e->chemistry, e->cooling_func);
   space_first_init_gparts(e->s, e->gravity_properties);
   space_first_init_sparts(e->s);

src/part.c

@@ -94,6 +94,26 @@ void part_relink_sparts_to_gparts(struct gpart *gparts, size_t N,
   }
 }
 
+/**
+ * @brief Re-link both the #part%s and #spart%s associated with the list of
+ * #gpart%s.
+ *
+ * @param gparts The list of #gpart.
+ * @param N The number of particles to re-link;
+ * @param parts The global #part array in which to find the #gpart offsets.
+ * @param sparts The global #spart array in which to find the #gpart offsets.
+ */
+void part_relink_all_parts_to_gparts(struct gpart *gparts, size_t N,
+                                     struct part *parts, struct spart *sparts) {
+  for (size_t k = 0; k < N; k++) {
+    if (gparts[k].type == swift_type_gas) {
+      parts[-gparts[k].id_or_neg_offset].gpart = &gparts[k];
+    } else if (gparts[k].type == swift_type_star) {
+      sparts[-gparts[k].id_or_neg_offset].gpart = &gparts[k];
+    }
+  }
+}
+
 /**
  * @brief Verifies that the #gpart, #part and #spart are correctly linked
  * together
@@ -128,19 +148,19 @@ void part_verify_links(struct part *parts, struct gpart *gparts,
 
       /* Check that it is linked */
       if (gparts[k].id_or_neg_offset > 0)
-        error("Gas gpart not linked to anything !");
+        error("Gas gpart not linked to anything!");
 
       /* Find its link */
       const struct part *part = &parts[-gparts[k].id_or_neg_offset];
 
       /* Check the reverse link */
-      if (part->gpart != &gparts[k]) error("Linking problem !");
+      if (part->gpart != &gparts[k]) error("Linking problem!");
 
       /* Check that the particles are at the same place */
       if (gparts[k].x[0] != part->x[0] || gparts[k].x[1] != part->x[1] ||
           gparts[k].x[2] != part->x[2])
         error(
-            "Linked particles are not at the same position !\n"
+            "Linked particles are not at the same position!\n"
             "gp->x=[%e %e %e] p->x=[%e %e %e] diff=[%e %e %e]",
             gparts[k].x[0], gparts[k].x[1], gparts[k].x[2], part->x[0],
             part->x[1], part->x[2], gparts[k].x[0] - part->x[0],

src/part.h

@@ -80,6 +80,8 @@ void part_relink_parts_to_gparts(struct gpart *gparts, size_t N,
                                  struct part *parts);
 void part_relink_sparts_to_gparts(struct gpart *gparts, size_t N,
                                   struct spart *sparts);
+void part_relink_all_parts_to_gparts(struct gpart *gparts, size_t N,
+                                     struct part *parts, struct spart *sparts);
 void part_verify_links(struct part *parts, struct gpart *gparts,
                        struct spart *sparts, size_t nr_parts, size_t nr_gparts,
                        size_t nr_sparts, int verbose);

src/space.h

@@ -173,12 +173,14 @@ struct space {
 };
 
 /* function prototypes. */
-void space_parts_sort(struct space *s, int *ind, size_t N, int min, int max,
-                      int verbose);
-void space_gparts_sort(struct space *s, int *ind, size_t N, int min, int max,
-                       int verbose);
-void space_sparts_sort(struct space *s, int *ind, size_t N, int min, int max,
-                       int verbose);
+void space_free_buff_sort_indices(struct space *s);
+void space_parts_sort(struct part *parts, struct xpart *xparts, int *ind,
+                      int *counts, int num_bins, ptrdiff_t parts_offset);
+void space_gparts_sort(struct gpart *gparts, struct part *parts,
+                       struct spart *sparts, int *ind, int *counts,
+                       int num_bins);
+void space_sparts_sort(struct spart *sparts, int *ind, int *counts,
+                       int num_bins, ptrdiff_t sparts_offset);
 void space_getcells(struct space *s, int nr_cells, struct cell **cells);
 int space_getsid(struct space *s, struct cell **ci, struct cell **cj,
                  double *shift);
@@ -199,12 +201,6 @@ void space_map_parts_xparts(struct space *s,
                                         struct cell *c));
 void space_map_cells_post(struct space *s, int full,
                           void (*fun)(struct cell *c, void *data), void *data);
-void space_parts_sort_mapper(void *map_data, int num_elements,
-                             void *extra_data);
-void space_gparts_sort_mapper(void *map_data, int num_elements,
-                              void *extra_data);
-void space_sparts_sort_mapper(void *map_data, int num_elements,
-                              void *extra_data);
 void space_rebuild(struct space *s, int verbose);
 void space_recycle(struct space *s, struct cell *c);
 void space_recycle_list(struct space *s, struct cell *cell_list_begin,
@@ -215,12 +211,12 @@ void space_split(struct space *s, struct cell *cells, int nr_cells,
                  int verbose);
 void space_split_mapper(void *map_data, int num_elements, void *extra_data);
 void space_list_cells_with_tasks(struct space *s);
-void space_parts_get_cell_index(struct space *s, int *ind, struct cell *cells,
-                                int verbose);
-void space_gparts_get_cell_index(struct space *s, int *gind, struct cell *cells,
-                                 int verbose);
-void space_sparts_get_cell_index(struct space *s, int *sind, struct cell *cells,
-                                 int verbose);
+void space_parts_get_cell_index(struct space *s, int *ind, int *cell_counts,
+                                struct cell *cells, int verbose);
+void space_gparts_get_cell_index(struct space *s, int *gind, int *cell_counts,
+                                 struct cell *cells, int verbose);
+void space_sparts_get_cell_index(struct space *s, int *sind, int *cell_counts,
+                                 struct cell *cells, int verbose);
 void space_synchronize_particle_positions(struct space *s);
 void space_do_parts_sort();
 void space_do_gparts_sort();