Summary

Obsolete the unused flags Tier2CompileThreshold and Tier2BackEdgeThreshold.

Problem

The flag Tier2CompileThreshold has no effect as of JDK-8255429.

The flag Tier2BackEdgeThreshold has no effect as of JDK-6953144.

Solution

Obsolete Tier2CompileThreshold and Tier2BackEdgeThreshold in JDK 25 and expire them in JDK 26.

Specification

diff --git a/src/hotspot/share/compiler/compiler_globals.hpp b/src/hotspot/share/compiler/compiler_globals.hpp
index a811cd8b3ba..c3bdf1ef092 100644
--- a/src/hotspot/share/compiler/compiler_globals.hpp
+++ b/src/hotspot/share/compiler/compiler_globals.hpp
@@ -167,14 +167,6 @@
           "frequency")                                                      \
           range(0, 30)                                                      \
                                                                             \
-  product(intx, Tier2CompileThreshold, 0,                                   \
-          "threshold at which tier 2 compilation is invoked")               \
-          range(0, max_jint)                                                \
-                                                                            \
-  product(intx, Tier2BackEdgeThreshold, 0,                                  \
-          "Back edge threshold at which tier 2 compilation is invoked")     \
-          range(0, max_jint)                                                \
-                                                                            \
   product(intx, Tier3InvocationThreshold, 200,                              \
           "Compile if number of method invocations crosses this "           \
           "threshold")                                                      \

diff --git a/src/hotspot/share/runtime/arguments.cpp b/src/hotspot/share/runtime/arguments.cpp
index 88e409f2d3a..e30b1476f39 100644
--- a/src/hotspot/share/runtime/arguments.cpp
+++ b/src/hotspot/share/runtime/arguments.cpp
@@ -534,6 +534,8 @@ static SpecialFlag const special_jvm_flags[] = {

   { "MetaspaceReclaimPolicy",       JDK_Version::undefined(), JDK_Version::jdk(21), JDK_Version::undefined() },
   { "ZGenerational",                JDK_Version::jdk(23), JDK_Version::jdk(24), JDK_Version::undefined() },
+  { "Tier2CompileThreshold",        JDK_Version::undefined(), JDK_Version::jdk(25), JDK_Version::jdk(26) },
+  { "Tier2BackEdgeThreshold",       JDK_Version::undefined(), JDK_Version::jdk(25), JDK_Version::jdk(26) },

 #ifdef ASSERT
   { "DummyObsoleteTestFlag",        JDK_Version::undefined(), JDK_Version::jdk(18), JDK_Version::undefined() },

diff --git a/test/hotspot/jtreg/vmTestbase/jit/t/t105/t105.java b/test/hotspot/jtreg/vmTestbase/jit/t/t105/t105.java
index 7b24ed2fec9..8660baaa22c 100644
--- a/test/hotspot/jtreg/vmTestbase/jit/t/t105/t105.java
+++ b/test/hotspot/jtreg/vmTestbase/jit/t/t105/t105.java
@@ -31,7 +31,7 @@
  * @library /vmTestbase
  *          /test/lib
  * @run main/othervm -XX:-OmitStackTraceInFastThrow jit.t.t105.t105
- * @run main/othervm -XX:-OmitStackTraceInFastThrow -Xbatch -XX:Tier0BackedgeNotifyFreqLog=0 -XX:Tier2BackedgeNotifyFreqLog=0 -XX:Tier3BackedgeNotifyFreqLog=0 -XX:Tier2BackEdgeThreshold=1 -XX:Tier3BackEdgeThreshold=1 -XX:Tier4BackEdgeThreshold=1 jit.t.t105.t105
+ * @run main/othervm -XX:-OmitStackTraceInFastThrow -Xbatch -XX:Tier0BackedgeNotifyFreqLog=0 -XX:Tier2BackedgeNotifyFreqLog=0 -XX:Tier3BackedgeNotifyFreqLog=0 -XX:Tier3BackEdgeThreshold=1 -XX:Tier4BackEdgeThreshold=1 jit.t.t105.t105
  *
  * This test must be run with OmitStackTraceInFastThrow disabled to avoid preallocated
  * exceptions. They don't have the detailed message that this test relies on.

Full PR for reference: https://github.com/openjdk/jdk/pull/18904