don't need to sweep rest.

`transient_heap_evacuate()` disables GC using `rb_gc_disable()`
to prohibt GC invocation because of new allocation for evacuated
memory. However, `rb_gc_disable()` sweep all rest of unswept pages.
We don't need to cancel lazy sweep so this patch introduce
`rb_gc_disable_no_rest()` which doesn't cancel lazy sweep.

1 files changed, 10 insertions, 5 deletions

diff --git a/gc.c b/gc.c
index af44914c39..f344bb88b1 100644
--- a/gc.c
+++ b/gc.c
@@ -8938,6 +8938,15 @@ rb_gc_enable(void)
     return old ? Qtrue : Qfalse;
 }
 
+VALUE
+rb_gc_disable_no_rest(void)
+{
+    rb_objspace_t *objspace = &rb_objspace;
+    int old = dont_gc;
+    dont_gc = TRUE;
+    return old ? Qtrue : Qfalse;
+}
+
 /*
  *  call-seq:
  *     GC.disable    -> true or false
@@ -8954,12 +8963,8 @@ VALUE
 rb_gc_disable(void)
 {
     rb_objspace_t *objspace = &rb_objspace;
-    int old = dont_gc;
-
     gc_rest(objspace);
-
-    dont_gc = TRUE;
-    return old ? Qtrue : Qfalse;
+    return rb_gc_disable_no_rest();
 }
 
 static int