--- a/src/hotspot/share/code/nmethod.cpp	Tue Jun 05 23:10:54 2018 +0530
+++ b/src/hotspot/share/code/nmethod.cpp	Wed May 02 11:28:49 2018 -0400
@@ -946,21 +946,8 @@
 void nmethod::verify_clean_inline_caches() {
   assert_locked_or_safepoint(CompiledIC_lock);
 
-  // If the method is not entrant or zombie then a JMP is plastered over the
-  // first few bytes.  If an oop in the old code was there, that oop
-  // should not get GC'd.  Skip the first few bytes of oops on
-  // not-entrant methods.
-  address low_boundary = verified_entry_point();
-  if (!is_in_use()) {
-    low_boundary += NativeJump::instruction_size;
-    // %%% Note:  On SPARC we patch only a 4-byte trap, not a full NativeJump.
-    // This means that the low_boundary is going to be a little too high.
-    // This shouldn't matter, since oops of non-entrant methods are never used.
-    // In fact, why are we bothering to look at oops in a non-entrant method??
-  }
-
   ResourceMark rm;
-  RelocIterator iter(this, low_boundary);
+  RelocIterator iter(this, oops_reloc_begin());
   while(iter.next()) {
     switch(iter.type()) {
       case relocInfo::virtual_call_type:
@@ -1041,13 +1028,17 @@
   flush_dependencies(/*delete_immediately*/false);
 
   // Break cycle between nmethod & method
-  LogTarget(Trace, class, unload) lt;
+  LogTarget(Trace, class, unload, nmethod) lt;
   if (lt.is_enabled()) {
     LogStream ls(lt);
-    ls.print_cr("making nmethod " INTPTR_FORMAT
-                  " unloadable, Method*(" INTPTR_FORMAT
-                  "), cause(" INTPTR_FORMAT ")",
-                  p2i(this), p2i(_method), p2i(cause));
+    ls.print("making nmethod " INTPTR_FORMAT
+             " unloadable, Method*(" INTPTR_FORMAT
+             "), cause(" INTPTR_FORMAT ") ",
+             p2i(this), p2i(_method), p2i(cause));
+     if (cause != NULL) {
+       cause->print_value_on(&ls);
+     }
+     ls.cr();
   }
   // Unlink the osr method, so we do not look this up again
   if (is_osr_method()) {
@@ -1378,17 +1369,15 @@
 
 
 // If this oop is not live, the nmethod can be unloaded.
-bool nmethod::can_unload(BoolObjectClosure* is_alive, oop* root, bool unloading_occurred) {
+bool nmethod::can_unload(BoolObjectClosure* is_alive, oop* root) {
   assert(root != NULL, "just checking");
   oop obj = *root;
   if (obj == NULL || is_alive->do_object_b(obj)) {
       return false;
   }
 
-  // If ScavengeRootsInCode is true, an nmethod might be unloaded
-  // simply because one of its constant oops has gone dead.
+  // An nmethod might be unloaded simply because one of its constant oops has gone dead.
   // No actual classes need to be unloaded in order for this to occur.
-  assert(unloading_occurred || ScavengeRootsInCode, "Inconsistency in unloading");
   make_unloaded(obj);
   return true;
 }
@@ -1466,7 +1455,7 @@
   set_unload_reported();
 }
 
-bool nmethod::unload_if_dead_at(RelocIterator* iter_at_oop, BoolObjectClosure *is_alive, bool unloading_occurred) {
+bool nmethod::unload_if_dead_at(RelocIterator* iter_at_oop, BoolObjectClosure *is_alive) {
   assert(iter_at_oop->type() == relocInfo::oop_type, "Wrong relocation type");
 
   oop_Relocation* r = iter_at_oop->oop_reloc();
@@ -1477,7 +1466,7 @@
          "oop must be found in exactly one place");
   if (r->oop_is_immediate() && r->oop_value() != NULL) {
     // Unload this nmethod if the oop is dead.
-    if (can_unload(is_alive, r->oop_addr(), unloading_occurred)) {
+    if (can_unload(is_alive, r->oop_addr())) {
       return true;;
     }
   }
@@ -1485,18 +1474,18 @@
   return false;
 }
 
-bool nmethod::do_unloading_scopes(BoolObjectClosure* is_alive, bool unloading_occurred) {
+bool nmethod::do_unloading_scopes(BoolObjectClosure* is_alive) {
   // Scopes
   for (oop* p = oops_begin(); p < oops_end(); p++) {
     if (*p == Universe::non_oop_word())  continue;  // skip non-oops
-    if (can_unload(is_alive, p, unloading_occurred)) {
+    if (can_unload(is_alive, p)) {
       return true;
     }
   }
   return false;
 }
 
-bool nmethod::do_unloading_oops(address low_boundary, BoolObjectClosure* is_alive, bool unloading_occurred) {
+bool nmethod::do_unloading_oops(address low_boundary, BoolObjectClosure* is_alive) {
   // Compiled code
 
   // Prevent extra code cache walk for platforms that don't have immediate oops.
@@ -1504,18 +1493,18 @@
     RelocIterator iter(this, low_boundary);
     while (iter.next()) {
       if (iter.type() == relocInfo::oop_type) {
-        if (unload_if_dead_at(&iter, is_alive, unloading_occurred)) {
+        if (unload_if_dead_at(&iter, is_alive)) {
           return true;
         }
       }
     }
   }
 
-  return do_unloading_scopes(is_alive, unloading_occurred);
+  return do_unloading_scopes(is_alive);
 }
 
 #if INCLUDE_JVMCI
-bool nmethod::do_unloading_jvmci(bool unloading_occurred) {
+bool nmethod::do_unloading_jvmci() {
   if (_jvmci_installed_code != NULL) {
     if (JNIHandles::is_global_weak_cleared(_jvmci_installed_code)) {
       if (_jvmci_installed_code_triggers_unloading) {
@@ -1533,15 +1522,9 @@
 
 // Iterate over metadata calling this function.   Used by RedefineClasses
 void nmethod::metadata_do(void f(Metadata*)) {
-  address low_boundary = verified_entry_point();
-  if (is_not_entrant()) {
-    low_boundary += NativeJump::instruction_size;
-    // %%% Note:  On SPARC we patch only a 4-byte trap, not a full NativeJump.
-    // (See comment above.)
-  }
   {
     // Visit all immediate references that are embedded in the instruction stream.
-    RelocIterator iter(this, low_boundary);
+    RelocIterator iter(this, oops_reloc_begin());
     while (iter.next()) {
       if (iter.type() == relocInfo::metadata_type ) {
         metadata_Relocation* r = iter.metadata_reloc();
@@ -1588,20 +1571,9 @@
   assert(allow_zombie || !is_zombie(), "should not call follow on zombie nmethod");
   assert(!is_unloaded(), "should not call follow on unloaded nmethod");
 
-  // If the method is not entrant or zombie then a JMP is plastered over the
-  // first few bytes.  If an oop in the old code was there, that oop
-  // should not get GC'd.  Skip the first few bytes of oops on
-  // not-entrant methods.
-  address low_boundary = verified_entry_point();
-  if (is_not_entrant()) {
-    low_boundary += NativeJump::instruction_size;
-    // %%% Note:  On SPARC we patch only a 4-byte trap, not a full NativeJump.
-    // (See comment above.)
-  }
-
   // Prevent extra code cache walk for platforms that don't have immediate oops.
   if (relocInfo::mustIterateImmediateOopsInCode()) {
-    RelocIterator iter(this, low_boundary);
+    RelocIterator iter(this, oops_reloc_begin());
 
     while (iter.next()) {
       if (iter.type() == relocInfo::oop_type ) {
@@ -1650,7 +1622,11 @@
           break;
       }
       // Mark was clear when we first saw this guy.
-      if (TraceScavenge) { print_on(tty, "oops_do, mark"); }
+      LogTarget(Trace, gc, nmethod) lt;
+      if (lt.is_enabled()) {
+        LogStream ls(lt);
+        CompileTask::print(&ls, this, "oops_do, mark", /*short_form:*/ true);
+      }
       return false;
     }
   }
@@ -1659,7 +1635,7 @@
 }
 
 void nmethod::oops_do_marking_prologue() {
-  if (TraceScavenge) { tty->print_cr("[oops_do_marking_prologue"); }
+  log_trace(gc, nmethod)("oops_do_marking_prologue");
   assert(_oops_do_mark_nmethods == NULL, "must not call oops_do_marking_prologue twice in a row");
   // We use cmpxchg instead of regular assignment here because the user
   // may fork a bunch of threads, and we need them all to see the same state.
@@ -1675,20 +1651,26 @@
     nmethod* next = cur->_oops_do_mark_link;
     cur->_oops_do_mark_link = NULL;
     DEBUG_ONLY(cur->verify_oop_relocations());
-    NOT_PRODUCT(if (TraceScavenge)  cur->print_on(tty, "oops_do, unmark"));
+
+    LogTarget(Trace, gc, nmethod) lt;
+    if (lt.is_enabled()) {
+      LogStream ls(lt);
+      CompileTask::print(&ls, cur, "oops_do, unmark", /*short_form:*/ true);
+    }
     cur = next;
   }
   nmethod* required = _oops_do_mark_nmethods;
   nmethod* observed = Atomic::cmpxchg((nmethod*)NULL, &_oops_do_mark_nmethods, required);
   guarantee(observed == required, "no races in this sequential code");
-  if (TraceScavenge) { tty->print_cr("oops_do_marking_epilogue]"); }
+  log_trace(gc, nmethod)("oops_do_marking_epilogue");
 }
 
 class DetectScavengeRoot: public OopClosure {
   bool     _detected_scavenge_root;
+  nmethod* _print_nm;
 public:
-  DetectScavengeRoot() : _detected_scavenge_root(false)
-  { NOT_PRODUCT(_print_nm = NULL); }
+  DetectScavengeRoot(nmethod* nm) : _detected_scavenge_root(false), _print_nm(nm) {}
+
   bool detected_scavenge_root() { return _detected_scavenge_root; }
   virtual void do_oop(oop* p) {
     if ((*p) != NULL && Universe::heap()->is_scavengable(*p)) {
@@ -1699,21 +1681,25 @@
   virtual void do_oop(narrowOop* p) { ShouldNotReachHere(); }
 
 #ifndef PRODUCT
-  nmethod* _print_nm;
   void maybe_print(oop* p) {
-    if (_print_nm == NULL)  return;
-    if (!_detected_scavenge_root)  _print_nm->print_on(tty, "new scavenge root");
-    tty->print_cr("" PTR_FORMAT "[offset=%d] detected scavengable oop " PTR_FORMAT " (found at " PTR_FORMAT ")",
-                  p2i(_print_nm), (int)((intptr_t)p - (intptr_t)_print_nm),
-                  p2i(*p), p2i(p));
-    (*p)->print();
+    LogTarget(Trace, gc, nmethod) lt;
+    if (lt.is_enabled()) {
+      LogStream ls(lt);
+      if (!_detected_scavenge_root) {
+        CompileTask::print(&ls, _print_nm, "new scavenge root", /*short_form:*/ true);
+      }
+      ls.print("" PTR_FORMAT "[offset=%d] detected scavengable oop " PTR_FORMAT " (found at " PTR_FORMAT ") ",
+               p2i(_print_nm), (int)((intptr_t)p - (intptr_t)_print_nm),
+               p2i(*p), p2i(p));
+      (*p)->print_value_on(&ls);
+      ls.cr();
+    }
   }
 #endif //PRODUCT
 };
 
 bool nmethod::detect_scavenge_root_oops() {
-  DetectScavengeRoot detect_scavenge_root;
-  NOT_PRODUCT(if (TraceScavenge)  detect_scavenge_root._print_nm = this);
+  DetectScavengeRoot detect_scavenge_root(this);
   oops_do(&detect_scavenge_root);
   return detect_scavenge_root.detected_scavenge_root();
 }