--- a/src/hotspot/os/linux/os_linux.cpp	Sat May 25 20:55:33 2019 +0900
+++ b/src/hotspot/os/linux/os_linux.cpp	Thu May 23 15:15:01 2019 +0200
@@ -3450,6 +3450,7 @@
   assert(addr == bottom, "sanity check");
 
   size = align_up(pointer_delta(addr, bottom, 1) + size, os::Linux::page_size());
+  Events::log(NULL, "Protecting memory [" INTPTR_FORMAT "," INTPTR_FORMAT "] with protection modes %x", p2i(bottom), p2i(bottom+size), prot);
   return ::mprotect(bottom, size, prot) == 0;
 }