Skip malloc recording on non-main ractors

Author: jhawthorn

gc/default/default.c

@@ -8040,6 +8040,11 @@ objspace_malloc_increase_report(rb_objspace_t *objspace, void *mem, size_t new_s
 static bool
 objspace_malloc_increase_body(rb_objspace_t *objspace, void *mem, size_t new_size, size_t old_size, enum memop_type type, bool gc_allowed)
 {
+    if (!rb_ractor_main_p()) {
+        /* HACK: ignore mallocs on other Ractors */
+        return true;
+    }
+
     if (new_size > old_size) {
         RUBY_ATOMIC_SIZE_ADD(malloc_increase, new_size - old_size);
 #if RGENGC_ESTIMATE_OLDMALLOC