sort pages

RelationalAI · Oct 23, 2023 · a8530e1 · a8530e1
1 parent c540340
commit a8530e1
Showing 1 changed file with 16 additions and 1 deletion.
diff --git a/src/gc.c b/src/gc.c
@@ -1666,6 +1666,11 @@ void gc_free_pages(void)
     }
 }
 
+static int gc_pg_cmp(jl_gc_pagemeta_t *pg, jl_gc_pagemeta_t *pg2)
+{
+    return (pg->nfree - pg2->nfree);
+}
+
 // setup the data-structures for a sweep over all memory pools
 static void gc_sweep_pool(void)
 {
@@ -1743,18 +1748,28 @@ static void gc_sweep_pool(void)
         if (ptls2 == NULL) {
             continue;
         }
+        // create a temporary array of pages to sort them
+        arraylist_t a;
+        arraylist_new(&a, 0);
         jl_gc_pagemeta_t *pg = jl_atomic_load_relaxed(&ptls2->page_metadata_allocd.bottom);
         while (pg != NULL) {
             jl_gc_pagemeta_t *pg2 = pg->next;
+            arraylist_push(&a, pg);
+            pg = pg2;
+        }
+        // sort by number of free objects in ascending order
+        qsort(a.items, a.len, sizeof(jl_gc_pagemeta_t*), (int (*)(const void *, const void *))gc_pg_cmp);
+        for (int i = 0; i < a.len; i++) {
+            jl_gc_pagemeta_t *pg = (jl_gc_pagemeta_t*)a.items[i];
             if (pg->fl_begin_offset != UINT16_MAX) {
                 char *cur_pg = pg->data;
                 jl_taggedvalue_t *fl_beg = (jl_taggedvalue_t*)(cur_pg + pg->fl_begin_offset);
                 jl_taggedvalue_t *fl_end = (jl_taggedvalue_t*)(cur_pg + pg->fl_end_offset);
                 *pfl[t_i * JL_GC_N_POOLS + pg->pool_n] = fl_beg;
                 pfl[t_i * JL_GC_N_POOLS + pg->pool_n] = &fl_end->next;
             }
-            pg = pg2;
         }
+        arraylist_free(&a);
     }
 
     // null out terminal pointers of free lists