Fix the arena selection for oversized allocations.

Use the per-arena oversize_threshold, instead of the global setting.

src/arena.c

@@ -1770,7 +1770,7 @@ arena_choose_huge(tsd_t *tsd) {
 }
 
 bool
-arena_init_huge(void) {
+arena_init_huge(arena_t *a0) {
 	bool huge_enabled;
 
 	/* The threshold should be large size class. */
@@ -1783,6 +1783,9 @@ arena_init_huge(void) {
 		/* Reserve the index for the huge arena. */
 		huge_arena_ind = narenas_total_get();
 		oversize_threshold = opt_oversize_threshold;
+		/* a0 init happened before malloc_conf_init. */
+		atomic_store_zu(&a0->pa_shard.pac.oversize_threshold,
+		    oversize_threshold, ATOMIC_RELAXED);
 		huge_enabled = true;
 	}
 

src/jemalloc.c

@@ -2090,7 +2090,7 @@ malloc_init_narenas(void) {
 		    narenas_auto);
 	}
 	narenas_total_set(narenas_auto);
-	if (arena_init_huge()) {
+	if (arena_init_huge(a0)) {
 		narenas_total_inc();
 	}
 	manual_arena_base = narenas_total_get();