Summary

Deprecate the unsafe and unstable HotSpot option -XX:DeferPollingPageLoopCount=??.

Problem

The option is unsafe and unstable. The method SafepointSynchronize::begin have become really large and complicated. For future refactoring of this method we should now deprecate this option.

Solution

Deprecate the flag.

Specification

diff -r 2233409844b3 src/hotspot/share/runtime/arguments.cpp
--- a/src/hotspot/share/runtime/arguments.cpp   Wed Nov 15 16:24:46 2017 +0100
+++ b/src/hotspot/share/runtime/arguments.cpp   Wed Nov 15 16:31:58 2017 +0100
@@ -389,2 +389,3 @@
   { "DeferThrSuspendLoopCount",     JDK_Version::jdk(10), JDK_Version::jdk(11), JDK_Version::jdk(12) },
+  { "DeferPollingPageLoopCount",    JDK_Version::jdk(10), JDK_Version::jdk(11), JDK_Version::jdk(12) },
   { "IgnoreUnverifiableClassesDuringDump", JDK_Version::jdk(10),  JDK_Version::undefined(), JDK_Version::undefined() },
diff -r 2233409844b3 src/hotspot/share/runtime/globals.hpp
--- a/src/hotspot/share/runtime/globals.hpp Wed Nov 15 16:24:46 2017 +0100
+++ b/src/hotspot/share/runtime/globals.hpp Wed Nov 15 16:31:58 2017 +0100
@@ -3275,3 +3275,4 @@
   product(intx, DeferPollingPageLoopCount,     -1,                          \
-          "(Unsafe,Unstable) Number of iterations in safepoint loop "       \
+          "(Unsafe,Unstable,Deprecated) "                                   \
+          "Number of iterations in safepoint loop "                         \
           "before changing safepoint polling page to RO ")                  \