Merge pull request #108 from skybber/master

Update -XX:HotswapDeoptClassPath= for jdk8

2 files changed, 102 insertions, 49 deletions

diff --git a/README.md b/README.md
index 0375bd2c..d5c5adc2 100644
--- a/README.md
+++ b/README.md
@@ -80,4 +80,10 @@ To run tests from IDE, you need:
  * Add JVM argument to use redefinition agent (`-javaagent:agent/build/libs/agent.jar`).
  * Add JVM argument to DCEVM VM if installed side-by-side (`-XXaltjvm=dcevm`).
 
+### Hotswap performance tweak (Experimental)
+DCEVM executes deoptimization (purge of code cache) after any class redefinition. It leads to decrease JVM's performance (after redefinition).  This is especially problem on large scale projects with significant number of classes. Hotswap performance can be improved using an experimental option `-XX:HotswapDeoptClassPath=`. One or more packages can be specified in comma separated list as parameters. Packages must contain all classes that will be potentially modified (redefined). Classes outside of this list won't be included in the deoptimization. Usually it is sufficient to specify application main or root package. If `com.sun.proxy.Proxy` is used in the application or by application's framework, then this option should contain package `com.sun.proxy` as well. If `HotswapDeoptClassPath` option is not specified, then all classes will be deoptimized after redefinition.
+Example:
+
+    -XX:HotswapDeoptClassPath='com.myproject.,com.sun.proxy.$Proxy'
+
 ### Known issues
diff --git a/hotspot/.hg/patches/light-jdk8u66-b17-deopt-cp.patch b/hotspot/.hg/patches/light-jdk8u66-b17-deopt-cp.patch
index bef4c196..9362352d 100644
--- a/hotspot/.hg/patches/light-jdk8u66-b17-deopt-cp.patch
+++ b/hotspot/.hg/patches/light-jdk8u66-b17-deopt-cp.patch
@@ -1,40 +1,79 @@
-# HG changeset patch
-# Parent  5c1a815b73abcb755c43eb820f6557d37aeb4f9f
-
-diff -r 5c1a815b73ab src/share/vm/classfile/classFileParser.cpp
---- a/src/share/vm/classfile/classFileParser.cpp	Mon Dec 07 17:08:29 2015 -0800
-+++ b/src/share/vm/classfile/classFileParser.cpp	Mon Dec 07 17:11:00 2015 -0800
-@@ -4257,6 +4257,11 @@
+diff --git a/src/share/vm/classfile/classFileParser.cpp b/src/share/vm/classfile/classFileParser.cpp
+index fa7986b..0910a7d 100644
+--- a/src/share/vm/classfile/classFileParser.cpp
++++ b/src/share/vm/classfile/classFileParser.cpp
+@@ -4264,6 +4264,30 @@
        }
      }
  
-+    if (cfs->source() != NULL && HotswapDeoptClassPath != NULL) {
-+      if (strstr(cfs->source(), HotswapDeoptClassPath) != NULL) 
-+        this_klass->set_deoptimization_incl(true);
++    if (this_klass->external_name() != NULL && HotswapDeoptClassPath != NULL) {
++      const char* deopt_path = HotswapDeoptClassPath;
++      const char* const end = deopt_path + strlen(deopt_path);
++      bool deopt_found = false;
++      while (!deopt_found && deopt_path < end) {
++        const char* tmp_end = strchr(deopt_path, ',');
++        if (tmp_end == NULL) {
++          tmp_end = end;
++        }
++        char* deopt_segm_path = NEW_C_HEAP_ARRAY(char, tmp_end - deopt_path + 1, mtInternal);
++        memcpy(deopt_segm_path, deopt_path, tmp_end - deopt_path);
++        deopt_segm_path[tmp_end - deopt_path] = '\0';
++        if (strstr(this_klass->external_name(), deopt_segm_path) != NULL) {
++          if (TraceRedefineClasses > 0) {
++            tty->print_cr("Including in deoptimization : %s", this_klass->external_name());
++          }
++          this_klass->set_deoptimization_incl(true);
++          deopt_found = true;
++        }
++        FREE_C_HEAP_ARRAY(char, deopt_segm_path, mtInternal);
++        deopt_path = tmp_end + 1;
++      }
 +    }
 +
      if (TraceClassResolution) {
        ResourceMark rm;
        // print out the superclass.
-diff -r 5c1a815b73ab src/share/vm/classfile/systemDictionary.cpp
---- a/src/share/vm/classfile/systemDictionary.cpp	Mon Dec 07 17:08:29 2015 -0800
-+++ b/src/share/vm/classfile/systemDictionary.cpp	Mon Dec 07 17:11:00 2015 -0800
-@@ -1245,6 +1245,11 @@
+diff --git a/src/share/vm/classfile/systemDictionary.cpp b/src/share/vm/classfile/systemDictionary.cpp
+index e40b061..588e0e5 100644
+--- a/src/share/vm/classfile/systemDictionary.cpp
++++ b/src/share/vm/classfile/systemDictionary.cpp
+@@ -1255,6 +1255,31 @@
        ik->restore_unshareable_info(loader_data, protection_domain, CHECK_(nh));
      }
  
 +    if (HotswapDeoptClassPath != NULL) {
-+      if (strstr(HotswapDeoptClassPath, ik->external_name()) != NULL)
-+        ik->set_deoptimization_incl(true);
++      const char* deopt_path = HotswapDeoptClassPath;
++      const char* const end = deopt_path + strlen(deopt_path);
++      bool deopt_found = false;
++      while (!deopt_found && deopt_path < end) {
++        const char* tmp_end = strchr(deopt_path, ',');
++        if (tmp_end == NULL) {
++          tmp_end = end;
++        }
++        char* deopt_segm_path = NEW_C_HEAP_ARRAY(char, tmp_end - deopt_path + 1, mtInternal);
++        memcpy(deopt_segm_path, deopt_path, tmp_end - deopt_path);
++        deopt_segm_path[tmp_end - deopt_path] = '\0';
++        if (strstr(ik->external_name(), deopt_segm_path) != NULL) {
++          if (TraceRedefineClasses > 0) {
++            tty->print_cr("Including in deoptimization : %s", ik->external_name());
++          }
++          ik->set_deoptimization_incl(true);
++          deopt_found = true;
++        }
++        FREE_C_HEAP_ARRAY(char, deopt_segm_path, mtInternal);
++        deopt_path = tmp_end + 1;
++      }
 +    }
 +
++
      if (TraceClassLoading) {
        ResourceMark rm;
        tty->print("[Loaded %s", ik->external_name());
-diff -r 5c1a815b73ab src/share/vm/code/codeCache.cpp
---- a/src/share/vm/code/codeCache.cpp	Mon Dec 07 17:08:29 2015 -0800
-+++ b/src/share/vm/code/codeCache.cpp	Mon Dec 07 17:11:00 2015 -0800
-@@ -707,6 +707,13 @@
+diff --git a/src/share/vm/code/codeCache.cpp b/src/share/vm/code/codeCache.cpp
+index c9059d7..af10381 100644
+--- a/src/share/vm/code/codeCache.cpp
++++ b/src/share/vm/code/codeCache.cpp
+@@ -709,6 +709,13 @@
  }
  #endif // HOTSWAP
  
@@ -48,10 +87,11 @@ diff -r 5c1a815b73ab src/share/vm/code/codeCache.cpp
  
  // Deoptimize all methods
  void CodeCache::mark_all_nmethods_for_deoptimization() {
-diff -r 5c1a815b73ab src/share/vm/code/codeCache.hpp
---- a/src/share/vm/code/codeCache.hpp	Mon Dec 07 17:08:29 2015 -0800
-+++ b/src/share/vm/code/codeCache.hpp	Mon Dec 07 17:11:00 2015 -0800
-@@ -185,6 +185,7 @@
+diff --git a/src/share/vm/code/codeCache.hpp b/src/share/vm/code/codeCache.hpp
+index f098284..d4a1363 100644
+--- a/src/share/vm/code/codeCache.hpp
++++ b/src/share/vm/code/codeCache.hpp
+@@ -184,6 +184,7 @@
      // tells how many nmethods have dependencies
    static int number_of_nmethods_with_dependencies();
  
@@ -59,9 +99,10 @@ diff -r 5c1a815b73ab src/share/vm/code/codeCache.hpp
    static int get_codemem_full_count() { return _codemem_full_count; }
  };
  
-diff -r 5c1a815b73ab src/share/vm/code/nmethod.cpp
---- a/src/share/vm/code/nmethod.cpp	Mon Dec 07 17:08:29 2015 -0800
-+++ b/src/share/vm/code/nmethod.cpp	Mon Dec 07 17:11:00 2015 -0800
+diff --git a/src/share/vm/code/nmethod.cpp b/src/share/vm/code/nmethod.cpp
+index 6ea39ae..bf2db7e 100644
+--- a/src/share/vm/code/nmethod.cpp
++++ b/src/share/vm/code/nmethod.cpp
 @@ -476,6 +476,7 @@
    _lazy_critical_native       = 0;
    _has_wide_vectors           = 0;
@@ -114,9 +155,10 @@ diff -r 5c1a815b73ab src/share/vm/code/nmethod.cpp
      // Copy contents of ScopeDescRecorder to nmethod
      code_buffer->copy_values_to(this);
      debug_info->copy_to(this);
-diff -r 5c1a815b73ab src/share/vm/code/nmethod.hpp
---- a/src/share/vm/code/nmethod.hpp	Mon Dec 07 17:08:29 2015 -0800
-+++ b/src/share/vm/code/nmethod.hpp	Mon Dec 07 17:11:00 2015 -0800
+diff --git a/src/share/vm/code/nmethod.hpp b/src/share/vm/code/nmethod.hpp
+index b7d6890..3de4757 100644
+--- a/src/share/vm/code/nmethod.hpp
++++ b/src/share/vm/code/nmethod.hpp
 @@ -184,6 +184,8 @@
    bool _marked_for_reclamation;              // Used by NMethodSweeper (set only by sweeper)
    bool _marked_for_deoptimization;           // Used for stack deoptimization
@@ -138,9 +180,10 @@ diff -r 5c1a815b73ab src/share/vm/code/nmethod.hpp
    void  make_unloaded(BoolObjectClosure* is_alive, oop cause);
  
    bool has_dependencies()                         { return dependencies_size() != 0; }
-diff -r 5c1a815b73ab src/share/vm/oops/klass.cpp
---- a/src/share/vm/oops/klass.cpp	Mon Dec 07 17:08:29 2015 -0800
-+++ b/src/share/vm/oops/klass.cpp	Mon Dec 07 17:11:00 2015 -0800
+diff --git a/src/share/vm/oops/klass.cpp b/src/share/vm/oops/klass.cpp
+index 2e3d192..a889458 100644
+--- a/src/share/vm/oops/klass.cpp
++++ b/src/share/vm/oops/klass.cpp
 @@ -188,6 +188,7 @@
  
    set_redefinition_flags(Klass::NoRedefinition);
@@ -167,9 +210,10 @@ diff -r 5c1a815b73ab src/share/vm/oops/klass.cpp
      int sup_depth = sup->super_depth();
      juint my_depth  = MIN2(sup_depth + 1, (int)primary_super_limit());
      if (!can_be_primary_super_slow())
-diff -r 5c1a815b73ab src/share/vm/oops/klass.hpp
---- a/src/share/vm/oops/klass.hpp	Mon Dec 07 17:08:29 2015 -0800
-+++ b/src/share/vm/oops/klass.hpp	Mon Dec 07 17:11:00 2015 -0800
+diff --git a/src/share/vm/oops/klass.hpp b/src/share/vm/oops/klass.hpp
+index e3fc3bd..c5fc46d 100644
+--- a/src/share/vm/oops/klass.hpp
++++ b/src/share/vm/oops/klass.hpp
 @@ -177,6 +177,7 @@
    bool        _original_field_offsets_changed; // Did the original field offsets of this class change during class redefinition?
    int *       _update_information;     // Update information
@@ -188,9 +232,10 @@ diff -r 5c1a815b73ab src/share/vm/oops/klass.hpp
    // Revision number for redefined classes, -1 for originally loaded classes
    bool was_redefined() const            { return _revision_number != -1; }
    jint revision_number() const          { return _revision_number; }
-diff -r 5c1a815b73ab src/share/vm/prims/jvmtiRedefineClasses2.cpp
---- a/src/share/vm/prims/jvmtiRedefineClasses2.cpp	Mon Dec 07 17:08:29 2015 -0800
-+++ b/src/share/vm/prims/jvmtiRedefineClasses2.cpp	Mon Dec 07 17:11:00 2015 -0800
+diff --git a/src/share/vm/prims/jvmtiRedefineClasses2.cpp b/src/share/vm/prims/jvmtiRedefineClasses2.cpp
+index f545b98..4fad1cb 100644
+--- a/src/share/vm/prims/jvmtiRedefineClasses2.cpp
++++ b/src/share/vm/prims/jvmtiRedefineClasses2.cpp
 @@ -443,6 +443,8 @@
  
      new_class->set_redefinition_flags(redefinition_flags);
@@ -200,7 +245,7 @@ diff -r 5c1a815b73ab src/share/vm/prims/jvmtiRedefineClasses2.cpp
      _max_redefinition_flags = _max_redefinition_flags | redefinition_flags;
  
      if ((redefinition_flags & Klass::ModifyInstances) != 0) {
-@@ -1568,7 +1570,10 @@
+@@ -1572,7 +1574,10 @@
    if (0 && JvmtiExport::all_dependencies_are_recorded()) {
      Universe::flush_evol_dependents_on(k_h);
    } else {
@@ -212,10 +257,11 @@ diff -r 5c1a815b73ab src/share/vm/prims/jvmtiRedefineClasses2.cpp
  
      ResourceMark rm(THREAD);
      DeoptimizationMarker dm;
-diff -r 5c1a815b73ab src/share/vm/runtime/globals.hpp
---- a/src/share/vm/runtime/globals.hpp	Mon Dec 07 17:08:29 2015 -0800
-+++ b/src/share/vm/runtime/globals.hpp	Mon Dec 07 17:11:00 2015 -0800
-@@ -3947,7 +3947,15 @@
+diff --git a/src/share/vm/runtime/globals.hpp b/src/share/vm/runtime/globals.hpp
+index 9a51218..b8ca7bb 100644
+--- a/src/share/vm/runtime/globals.hpp
++++ b/src/share/vm/runtime/globals.hpp
+@@ -3962,7 +3962,16 @@
                                                                              \
    product_pd(bool, PreserveFramePointer,                                    \
               "Use the FP register for holding the frame pointer "           \
@@ -223,11 +269,12 @@ diff -r 5c1a815b73ab src/share/vm/runtime/globals.hpp
 +             "and not as a general purpose register.")                      \
 +                                                                            \
 +  product(ccstr, HotswapDeoptClassPath, NULL,                               \
-+          "Class path or fragment of the class path to a folder with "      \
-+          "classes allowed to be deoptimized on hotswap. If is not "        \
-+          "defined then all classes will be deoptimized on hotswap. "       \
-+          "That's default behaviour. Using this option the performance "    \
-+          "of hotswap can be considerably increased. ")
++          "Comma separated list of packages containing classes that are "   \
++          "expected to be redefined. If com.sun.proxy is used by "          \
++          "application and proxied class is redefined, then this option "   \
++          "should contain 'com.sun.proxy'. If the option is not defined, "  \
++          "then all classes will be deoptimized on hotswap. Using this "    \
++          "option improves hotswap performance. ")
 +
  
  /*