diff --git a/ChangeLog b/ChangeLog
index 7320f95d4b..ae7c4ca70e 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,10 @@
+Thu Nov 22 15:26:02 2012  NARUSE, Yui  <naruse@ruby-lang.org>
+
+	* vm_insnhelper.h: partly revert r37631 (DTrace support).
+	  "vm usage information is always collected, so uncomment the
+	  functions." causes performance impact. [Bug #7370]
+	  Off course this revert disables related probes.
+
 Thu Nov 22 14:14:36 2012  Akinori MUSHA  <knu@iDaemons.org>
 
 	* re.c (rb_memsearch_ss): Apply performance improvement to short
diff --git a/vm_insnhelper.h b/vm_insnhelper.h
index 2748cd57c7..62d9781bc9 100644
--- a/vm_insnhelper.h
+++ b/vm_insnhelper.h
@@ -62,12 +62,14 @@ enum {
 extern char ruby_vm_redefined_flag[BOP_LAST_];
 extern VALUE ruby_vm_const_missing_count;
 
+#if VM_COLLECT_USAGE_DETAILS
 #define COLLECT_USAGE_INSN(insn)           vm_collect_usage_insn(insn)
 #define COLLECT_USAGE_OPERAND(insn, n, op) vm_collect_usage_operand((insn), (n), ((VALUE)(op)))
 
-#if VM_COLLECT_USAGE_DETAILS
 #define COLLECT_USAGE_REGISTER(reg, s)     vm_collect_usage_register((reg), (s))
 #else
+#define COLLECT_USAGE_INSN(insn)		/* none */
+#define COLLECT_USAGE_OPERAND(insn, n, op)	/* none */
 #define COLLECT_USAGE_REGISTER(reg, s)		/* none */
 #endif