Merge

hotspot/src/share/vm/runtime/arguments.cpp

@@ -28,6 +28,7 @@
 #include "compiler/compilerOracle.hpp"
 #include "memory/allocation.inline.hpp"
 #include "memory/cardTableRS.hpp"
+#include "memory/genCollectedHeap.hpp"
 #include "memory/referenceProcessor.hpp"
 #include "memory/universe.inline.hpp"
 #include "oops/oop.inline.hpp"
@@ -54,6 +55,8 @@
 #endif
 #if INCLUDE_ALL_GCS
 #include "gc_implementation/concurrentMarkSweep/compactibleFreeListSpace.hpp"
+#include "gc_implementation/g1/g1CollectedHeap.inline.hpp"
+#include "gc_implementation/parallelScavenge/parallelScavengeHeap.hpp"
 #endif // INCLUDE_ALL_GCS
 
 // Note: This is a special bug reporting site for the JVM
@@ -90,6 +93,7 @@ char*  Arguments::_java_command                 = NULL;
 SystemProperty* Arguments::_system_properties   = NULL;
 const char*  Arguments::_gc_log_filename        = NULL;
 bool   Arguments::_has_profile                  = false;
+size_t Arguments::_conservative_max_heap_alignment = 0;
 uintx  Arguments::_min_heap_size                = 0;
 Arguments::Mode Arguments::_mode                = _mixed;
 bool   Arguments::_java_compiler                = false;
@@ -1391,10 +1395,17 @@ bool verify_object_alignment() {
   return true;
 }
 
-inline uintx max_heap_for_compressed_oops() {
+uintx Arguments::max_heap_for_compressed_oops() {
   // Avoid sign flip.
   assert(OopEncodingHeapMax > (uint64_t)os::vm_page_size(), "Unusual page size");
-  LP64_ONLY(return OopEncodingHeapMax - os::vm_page_size());
+  // We need to fit both the NULL page and the heap into the memory budget, while
+  // keeping alignment constraints of the heap. To guarantee the latter, as the
+  // NULL page is located before the heap, we pad the NULL page to the conservative
+  // maximum alignment that the GC may ever impose upon the heap.
+  size_t displacement_due_to_null_page = align_size_up_(os::vm_page_size(),
+    Arguments::conservative_max_heap_alignment());
+
+  LP64_ONLY(return OopEncodingHeapMax - displacement_due_to_null_page);
   NOT_LP64(ShouldNotReachHere(); return 0);
 }
 
@@ -1439,7 +1450,7 @@ void Arguments::set_use_compressed_oops() {
     if (UseCompressedOops && !FLAG_IS_DEFAULT(UseCompressedOops)) {
       warning("Max heap size too large for Compressed Oops");
       FLAG_SET_DEFAULT(UseCompressedOops, false);
-      FLAG_SET_DEFAULT(UseCompressedKlassPointers, false);
+      FLAG_SET_DEFAULT(UseCompressedClassPointers, false);
     }
   }
 #endif // _LP64
@@ -1452,22 +1463,22 @@ void Arguments::set_use_compressed_oops() {
 void Arguments::set_use_compressed_klass_ptrs() {
 #ifndef ZERO
 #ifdef _LP64
-  // UseCompressedOops must be on for UseCompressedKlassPointers to be on.
+  // UseCompressedOops must be on for UseCompressedClassPointers to be on.
   if (!UseCompressedOops) {
-    if (UseCompressedKlassPointers) {
-      warning("UseCompressedKlassPointers requires UseCompressedOops");
+    if (UseCompressedClassPointers) {
+      warning("UseCompressedClassPointers requires UseCompressedOops");
     }
-    FLAG_SET_DEFAULT(UseCompressedKlassPointers, false);
+    FLAG_SET_DEFAULT(UseCompressedClassPointers, false);
   } else {
-    // Turn on UseCompressedKlassPointers too
-    if (FLAG_IS_DEFAULT(UseCompressedKlassPointers)) {
-      FLAG_SET_ERGO(bool, UseCompressedKlassPointers, true);
+    // Turn on UseCompressedClassPointers too
+    if (FLAG_IS_DEFAULT(UseCompressedClassPointers)) {
+      FLAG_SET_ERGO(bool, UseCompressedClassPointers, true);
     }
-    // Check the ClassMetaspaceSize to make sure we use compressed klass ptrs.
-    if (UseCompressedKlassPointers) {
-      if (ClassMetaspaceSize > KlassEncodingMetaspaceMax) {
-        warning("Class metaspace size is too large for UseCompressedKlassPointers");
-        FLAG_SET_DEFAULT(UseCompressedKlassPointers, false);
+    // Check the CompressedClassSpaceSize to make sure we use compressed klass ptrs.
+    if (UseCompressedClassPointers) {
+      if (CompressedClassSpaceSize > KlassEncodingMetaspaceMax) {
+        warning("CompressedClassSpaceSize is too large for UseCompressedClassPointers");
+        FLAG_SET_DEFAULT(UseCompressedClassPointers, false);
       }
     }
   }
@@ -1475,6 +1486,23 @@ void Arguments::set_use_compressed_klass_ptrs() {
 #endif // !ZERO
 }
 
+void Arguments::set_conservative_max_heap_alignment() {
+  // The conservative maximum required alignment for the heap is the maximum of
+  // the alignments imposed by several sources: any requirements from the heap
+  // itself, the collector policy and the maximum page size we may run the VM
+  // with.
+  size_t heap_alignment = GenCollectedHeap::conservative_max_heap_alignment();
+#if INCLUDE_ALL_GCS
+  if (UseParallelGC) {
+    heap_alignment = ParallelScavengeHeap::conservative_max_heap_alignment();
+  } else if (UseG1GC) {
+    heap_alignment = G1CollectedHeap::conservative_max_heap_alignment();
+  }
+#endif // INCLUDE_ALL_GCS
+  _conservative_max_heap_alignment = MAX3(heap_alignment, os::max_page_size(),
+    CollectorPolicy::compute_max_alignment());
+}
+
 void Arguments::set_ergonomics_flags() {
 
   if (os::is_server_class_machine()) {
@@ -1503,6 +1531,8 @@ void Arguments::set_ergonomics_flags() {
     }
   }
 
+  set_conservative_max_heap_alignment();
+
 #ifndef ZERO
 #ifdef _LP64
   set_use_compressed_oops();
@@ -2193,8 +2223,8 @@ bool Arguments::check_vm_args_consistency() {
 
   status = status && verify_object_alignment();
 
-  status = status && verify_interval(ClassMetaspaceSize, 1*M, 3*G,
-                                      "ClassMetaspaceSize");
+  status = status && verify_interval(CompressedClassSpaceSize, 1*M, 3*G,
+                                      "CompressedClassSpaceSize");
 
   status = status && verify_interval(MarkStackSizeMax,
                                   1, (max_jint - 1), "MarkStackSizeMax");
@@ -3326,13 +3356,13 @@ void Arguments::set_shared_spaces_flags() {
     }
     UseSharedSpaces = false;
 #ifdef _LP64
-    if (!UseCompressedOops || !UseCompressedKlassPointers) {
+    if (!UseCompressedOops || !UseCompressedClassPointers) {
       vm_exit_during_initialization(
-        "Cannot dump shared archive when UseCompressedOops or UseCompressedKlassPointers is off.", NULL);
+        "Cannot dump shared archive when UseCompressedOops or UseCompressedClassPointers is off.", NULL);
     }
   } else {
-    // UseCompressedOops and UseCompressedKlassPointers must be on for UseSharedSpaces.
-    if (!UseCompressedOops || !UseCompressedKlassPointers) {
+    // UseCompressedOops and UseCompressedClassPointers must be on for UseSharedSpaces.
+    if (!UseCompressedOops || !UseCompressedClassPointers) {
       no_shared_spaces();
     }
 #endif
@@ -3558,6 +3588,11 @@ jint Arguments::parse(const JavaVMInitArgs* args) {
   no_shared_spaces();
 #endif // INCLUDE_CDS
 
+  return JNI_OK;
+}
+
+jint Arguments::apply_ergo() {
+
   // Set flags based on ergonomics.
   set_ergonomics_flags();
 
@@ -3633,7 +3668,7 @@ jint Arguments::parse(const JavaVMInitArgs* args) {
   FLAG_SET_DEFAULT(ProfileInterpreter, false);
   FLAG_SET_DEFAULT(UseBiasedLocking, false);
   LP64_ONLY(FLAG_SET_DEFAULT(UseCompressedOops, false));
-  LP64_ONLY(FLAG_SET_DEFAULT(UseCompressedKlassPointers, false));
+  LP64_ONLY(FLAG_SET_DEFAULT(UseCompressedClassPointers, false));
 #endif // CC_INTERP
 
 #ifdef COMPILER2
@@ -3662,6 +3697,10 @@ jint Arguments::parse(const JavaVMInitArgs* args) {
     DebugNonSafepoints = true;
   }
 
+  if (FLAG_IS_CMDLINE(CompressedClassSpaceSize) && !UseCompressedClassPointers) {
+    warning("Setting CompressedClassSpaceSize has no effect when compressed class pointers are not used");
+  }
+
 #ifndef PRODUCT
   if (CompileTheWorld) {
     // Force NmethodSweeper to sweep whole CodeCache each time.