8007074: SIGSEGV at ParMarkBitMap::verify_clear()

Summary: Replace the broken large pages implementation on Linux. New flag: -XX:+UseTransparentHugePages - Linux specific flag to turn on transparent huge page hinting with madvise(..., MAP_HUGETLB). Changed behavior: -XX:+UseLargePages - tries to use -XX:+UseTransparentHugePages before trying other large pages implementations (on Linux). Changed behavior: -XX:+UseHugeTLBFS - Use upfront allocation of Large Pages instead of using the broken implementation to dynamically committing large pages. Changed behavior: -XX:LargePageSizeInBytes - Turned off the ability to use this flag on Linux and provides warning to user if set to a value different than the OS chosen large page size. Changed behavior: Setting no large page size - Now defaults to use -XX:UseTransparentHugePages if the OS supports it. Previously, -XX:+UseHugeTLBFS was chosen if the OS was configured to use large pages.
Reviewed-by: tschatzl, dcubed, brutisso

src/os/bsd/vm/os_bsd.cpp

@@ -2325,7 +2325,9 @@ void os::large_page_init() {
 }
 
 
-char* os::reserve_memory_special(size_t bytes, char* req_addr, bool exec) {
+char* os::reserve_memory_special(size_t bytes, size_t alignment, char* req_addr, bool exec) {
+  fatal("This code is not used or maintained.");
+
   // "exec" is passed in but not used.  Creating the shared image for
   // the code cache doesn't have an SHM_X executable permission to check.
   assert(UseLargePages && UseSHM, "only for SHM large pages");
@@ -4752,3 +4754,8 @@ int os::get_core_path(char* buffer, size_t bufferSize) {
   return n;
 }
 
+#ifndef PRODUCT
+void TestReserveMemorySpecial_test() {
+  // No tests available for this platform
+}
+#endif

src/os/linux/vm/globals_linux.hpp

@@ -40,6 +40,9 @@
   product(bool, UseHugeTLBFS, false,                                    \
           "Use MAP_HUGETLB for large pages")                            \
                                                                         \
+  product(bool, UseTransparentHugePages, false,                         \
+          "Use MADV_HUGEPAGE for large pages")                          \
+                                                                        \
   product(bool, LoadExecStackDllInVMThread, true,                       \
           "Load DLLs with executable-stack attribute in the VM Thread") \
                                                                         \

src/os/linux/vm/os_linux.hpp

@@ -32,6 +32,7 @@ typedef int (*pthread_getattr_func_type) (pthread_t, pthread_attr_t *);
 
 class Linux {
   friend class os;
+  friend class TestReserveMemorySpecial;
 
   // For signal-chaining
 #define MAXSIGNUM 32
@@ -92,8 +93,21 @@ class Linux {
   static void rebuild_cpu_to_node_map();
   static GrowableArray<int>* cpu_to_node()    { return _cpu_to_node; }
 
+  static size_t find_large_page_size();
+  static size_t setup_large_page_size();
+
+  static bool setup_large_page_type(size_t page_size);
+  static bool transparent_huge_pages_sanity_check(bool warn, size_t pages_size);
   static bool hugetlbfs_sanity_check(bool warn, size_t page_size);
 
+  static char* reserve_memory_special_shm(size_t bytes, size_t alignment, char* req_addr, bool exec);
+  static char* reserve_memory_special_huge_tlbfs(size_t bytes, size_t alignment, char* req_addr, bool exec);
+  static char* reserve_memory_special_huge_tlbfs_only(size_t bytes, char* req_addr, bool exec);
+  static char* reserve_memory_special_huge_tlbfs_mixed(size_t bytes, size_t alignment, char* req_addr, bool exec);
+
+  static bool release_memory_special_shm(char* base, size_t bytes);
+  static bool release_memory_special_huge_tlbfs(char* base, size_t bytes);
+
   static void print_full_memory_info(outputStream* st);
   static void print_distro_info(outputStream* st);
   static void print_libversion_info(outputStream* st);

src/os/solaris/vm/os_solaris.cpp

@@ -3385,7 +3385,7 @@ bool os::Solaris::setup_large_pages(caddr_t start, size_t bytes, size_t align) {
   return true;
 }
 
-char* os::reserve_memory_special(size_t size, char* addr, bool exec) {
+char* os::reserve_memory_special(size_t size, size_t alignment, char* addr, bool exec) {
   fatal("os::reserve_memory_special should not be called on Solaris.");
   return NULL;
 }
@@ -6601,3 +6601,9 @@ int os::get_core_path(char* buffer, size_t bufferSize) {
 
   return strlen(buffer);
 }
+
+#ifndef PRODUCT
+void TestReserveMemorySpecial_test() {
+  // No tests available for this platform
+}
+#endif

src/os/windows/vm/os_windows.cpp

@@ -3156,7 +3156,12 @@ bool os::can_execute_large_page_memory() {
   return true;
 }
 
-char* os::reserve_memory_special(size_t bytes, char* addr, bool exec) {
+char* os::reserve_memory_special(size_t bytes, size_t alignment, char* addr, bool exec) {
+  assert(UseLargePages, "only for large pages");
+
+  if (!is_size_aligned(bytes, os::large_page_size()) || alignment > os::large_page_size()) {
+    return NULL; // Fallback to small pages.
+  }
 
   const DWORD prot = exec ? PAGE_EXECUTE_READWRITE : PAGE_READWRITE;
   const DWORD flags = MEM_RESERVE | MEM_COMMIT | MEM_LARGE_PAGES;
@@ -5638,3 +5643,9 @@ BOOL os::Advapi32Dll::AdvapiAvailable() {
 }
 
 #endif
+
+#ifndef PRODUCT
+void TestReserveMemorySpecial_test() {
+  // No tests available for this platform
+}
+#endif

src/share/vm/gc_implementation/g1/g1CollectedHeap.cpp

@@ -2006,10 +2006,12 @@ jint G1CollectedHeap::initialize() {
 
   size_t init_byte_size = collector_policy()->initial_heap_byte_size();
   size_t max_byte_size = collector_policy()->max_heap_byte_size();
+  size_t heap_alignment = collector_policy()->max_alignment();
 
   // Ensure that the sizes are properly aligned.
   Universe::check_alignment(init_byte_size, HeapRegion::GrainBytes, "g1 heap");
   Universe::check_alignment(max_byte_size, HeapRegion::GrainBytes, "g1 heap");
+  Universe::check_alignment(max_byte_size, heap_alignment, "g1 heap");
 
   _cg1r = new ConcurrentG1Refine(this);
 
@@ -2026,12 +2028,8 @@ jint G1CollectedHeap::initialize() {
   // If this happens then we could end up using a non-optimal
   // compressed oops mode.
 
-  // Since max_byte_size is aligned to the size of a heap region (checked
-  // above).
-  Universe::check_alignment(max_byte_size, HeapRegion::GrainBytes, "g1 heap");
-
   ReservedSpace heap_rs = Universe::reserve_heap(max_byte_size,
-                                                 HeapRegion::GrainBytes);
+                                                 heap_alignment);
 
   // It is important to do this in a way such that concurrent readers can't
   // temporarily think something is in the heap.  (I've actually seen this

src/share/vm/gc_implementation/g1/g1CollectorPolicy.cpp

@@ -313,7 +313,8 @@ G1CollectorPolicy::G1CollectorPolicy() :
 void G1CollectorPolicy::initialize_flags() {
   set_min_alignment(HeapRegion::GrainBytes);
   size_t card_table_alignment = GenRemSet::max_alignment_constraint(rem_set_name());
-  set_max_alignment(MAX2(card_table_alignment, min_alignment()));
+  size_t page_size = UseLargePages ? os::large_page_size() : os::vm_page_size();
+  set_max_alignment(MAX3(card_table_alignment, min_alignment(), page_size));
   if (SurvivorRatio < 1) {
     vm_exit_during_initialization("Invalid survivor ratio specified");
   }

src/share/vm/memory/collectorPolicy.cpp

@@ -193,6 +193,8 @@ size_t GenCollectorPolicy::compute_max_alignment() {
       alignment = lcm(os::large_page_size(), alignment);
   }
 
+  assert(alignment >= min_alignment(), "Must be");
+
   return alignment;
 }
 

src/share/vm/memory/genCollectedHeap.cpp

@@ -95,13 +95,13 @@ jint GenCollectedHeap::initialize() {
   guarantee(HeapWordSize == wordSize, "HeapWordSize must equal wordSize");
 
   // The heap must be at least as aligned as generations.
-  size_t alignment = Generation::GenGrain;
+  size_t gen_alignment = Generation::GenGrain;
 
   _gen_specs = gen_policy()->generations();
 
   // Make sure the sizes are all aligned.
   for (i = 0; i < _n_gens; i++) {
-    _gen_specs[i]->align(alignment);
+    _gen_specs[i]->align(gen_alignment);
   }
 
   // Allocate space for the heap.
@@ -109,9 +109,11 @@ jint GenCollectedHeap::initialize() {
   char* heap_address;
   size_t total_reserved = 0;
   int n_covered_regions = 0;
-  ReservedSpace heap_rs(0);
+  ReservedSpace heap_rs;
 
-  heap_address = allocate(alignment, &total_reserved,
+  size_t heap_alignment = collector_policy()->max_alignment();
+
+  heap_address = allocate(heap_alignment, &total_reserved,
                           &n_covered_regions, &heap_rs);
 
   if (!heap_rs.is_reserved()) {
@@ -168,6 +170,8 @@ char* GenCollectedHeap::allocate(size_t alignment,
   const size_t pageSize = UseLargePages ?
       os::large_page_size() : os::vm_page_size();
 
+  assert(alignment % pageSize == 0, "Must be");
+
   for (int i = 0; i < _n_gens; i++) {
     total_reserved += _gen_specs[i]->max_size();
     if (total_reserved < _gen_specs[i]->max_size()) {
@@ -175,24 +179,17 @@ char* GenCollectedHeap::allocate(size_t alignment,
     }
     n_covered_regions += _gen_specs[i]->n_covered_regions();
   }
-  assert(total_reserved % pageSize == 0,
-         err_msg("Gen size; total_reserved=" SIZE_FORMAT ", pageSize="
-                 SIZE_FORMAT, total_reserved, pageSize));
+  assert(total_reserved % alignment == 0,
+         err_msg("Gen size; total_reserved=" SIZE_FORMAT ", alignment="
+                 SIZE_FORMAT, total_reserved, alignment));
 
   // Needed until the cardtable is fixed to have the right number
   // of covered regions.
   n_covered_regions += 2;
 
-  if (UseLargePages) {
-    assert(total_reserved != 0, "total_reserved cannot be 0");
-    total_reserved = round_to(total_reserved, os::large_page_size());
-    if (total_reserved < os::large_page_size()) {
-      vm_exit_during_initialization(overflow_msg);
-    }
-  }
+  *_total_reserved = total_reserved;
+  *_n_covered_regions = n_covered_regions;
 
-      *_total_reserved = total_reserved;
-      *_n_covered_regions = n_covered_regions;
   *heap_rs = Universe::reserve_heap(total_reserved, alignment);
   return heap_rs->base();
 }

src/share/vm/memory/metaspace.cpp

@@ -345,7 +345,7 @@ class VirtualSpaceNode : public CHeapObj<mtClass> {
 };
 
   // byte_size is the size of the associated virtualspace.
-VirtualSpaceNode::VirtualSpaceNode(size_t byte_size) : _top(NULL), _next(NULL), _rs(0), _container_count(0) {
+VirtualSpaceNode::VirtualSpaceNode(size_t byte_size) : _top(NULL), _next(NULL), _rs(), _container_count(0) {
   // align up to vm allocation granularity
   byte_size = align_size_up(byte_size, os::vm_allocation_granularity());
 

src/share/vm/memory/universe.cpp

@@ -681,17 +681,23 @@ static const uint64_t NarrowOopHeapMax = (uint64_t(max_juint) + 1);
 // 32Gb
 // OopEncodingHeapMax == NarrowOopHeapMax << LogMinObjAlignmentInBytes;
 
-char* Universe::preferred_heap_base(size_t heap_size, NARROW_OOP_MODE mode) {
+char* Universe::preferred_heap_base(size_t heap_size, size_t alignment, NARROW_OOP_MODE mode) {
+  assert(is_size_aligned((size_t)OopEncodingHeapMax, alignment), "Must be");
+  assert(is_size_aligned((size_t)NarrowOopHeapMax, alignment), "Must be");
+  assert(is_size_aligned(heap_size, alignment), "Must be");
+
+  uintx heap_base_min_address_aligned = align_size_up(HeapBaseMinAddress, alignment);
+
   size_t base = 0;
 #ifdef _LP64
   if (UseCompressedOops) {
     assert(mode == UnscaledNarrowOop  ||
            mode == ZeroBasedNarrowOop ||
            mode == HeapBasedNarrowOop, "mode is invalid");
-    const size_t total_size = heap_size + HeapBaseMinAddress;
+    const size_t total_size = heap_size + heap_base_min_address_aligned;
     // Return specified base for the first request.
     if (!FLAG_IS_DEFAULT(HeapBaseMinAddress) && (mode == UnscaledNarrowOop)) {
-      base = HeapBaseMinAddress;
+      base = heap_base_min_address_aligned;
 
     // If the total size is small enough to allow UnscaledNarrowOop then
     // just use UnscaledNarrowOop.
@@ -742,6 +748,8 @@ char* Universe::preferred_heap_base(size_t heap_size, NARROW_OOP_MODE mode) {
     }
   }
 #endif
+
+  assert(is_ptr_aligned((char*)base, alignment), "Must be");
   return (char*)base; // also return NULL (don't care) for 32-bit VM
 }
 
@@ -867,27 +875,33 @@ ReservedSpace Universe::reserve_heap(size_t heap_size, size_t alignment) {
   size_t total_reserved = align_size_up(heap_size, alignment);
   assert(!UseCompressedOops || (total_reserved <= (OopEncodingHeapMax - os::vm_page_size())),
       "heap size is too big for compressed oops");
-  char* addr = Universe::preferred_heap_base(total_reserved, Universe::UnscaledNarrowOop);
 
-  ReservedHeapSpace total_rs(total_reserved, alignment, UseLargePages, addr);
+  bool use_large_pages = UseLargePages && is_size_aligned(alignment, os::large_page_size());
+  assert(!UseLargePages
+      || UseParallelOldGC
+      || use_large_pages, "Wrong alignment to use large pages");
+
+  char* addr = Universe::preferred_heap_base(total_reserved, alignment, Universe::UnscaledNarrowOop);
+
+  ReservedHeapSpace total_rs(total_reserved, alignment, use_large_pages, addr);
 
   if (UseCompressedOops) {
     if (addr != NULL && !total_rs.is_reserved()) {
       // Failed to reserve at specified address - the requested memory
       // region is taken already, for example, by 'java' launcher.
       // Try again to reserver heap higher.
-      addr = Universe::preferred_heap_base(total_reserved, Universe::ZeroBasedNarrowOop);
+      addr = Universe::preferred_heap_base(total_reserved, alignment, Universe::ZeroBasedNarrowOop);
 
       ReservedHeapSpace total_rs0(total_reserved, alignment,
-                                  UseLargePages, addr);
+          use_large_pages, addr);
 
       if (addr != NULL && !total_rs0.is_reserved()) {
         // Failed to reserve at specified address again - give up.
-        addr = Universe::preferred_heap_base(total_reserved, Universe::HeapBasedNarrowOop);
+        addr = Universe::preferred_heap_base(total_reserved, alignment, Universe::HeapBasedNarrowOop);
         assert(addr == NULL, "");
 
         ReservedHeapSpace total_rs1(total_reserved, alignment,
-                                    UseLargePages, addr);
+            use_large_pages, addr);
         total_rs = total_rs1;
       } else {
         total_rs = total_rs0;

src/share/vm/memory/universe.hpp

@@ -346,7 +346,7 @@ class Universe: AllStatic {
   };
   static NARROW_OOP_MODE narrow_oop_mode();
   static const char* narrow_oop_mode_to_string(NARROW_OOP_MODE mode);
-  static char*    preferred_heap_base(size_t heap_size, NARROW_OOP_MODE mode);
+  static char*    preferred_heap_base(size_t heap_size, size_t alignment, NARROW_OOP_MODE mode);
   static char*    preferred_metaspace_base(size_t heap_size, NARROW_OOP_MODE mode);
   static address  narrow_oop_base()                       { return  _narrow_oop._base; }
   static bool  is_narrow_oop_base(void* addr)             { return (narrow_oop_base() == (address)addr); }

src/share/vm/prims/jni.cpp

@@ -5027,9 +5027,15 @@ _JNI_IMPORT_OR_EXPORT_ jint JNICALL JNI_GetDefaultJavaVMInitArgs(void *args_) {
   tty->print_cr("Running test: " #unit_test_function_call); \
   unit_test_function_call
 
+// Forward declaration
+void TestReservedSpace_test();
+void TestReserveMemorySpecial_test();
+
 void execute_internal_vm_tests() {
   if (ExecuteInternalVMTests) {
     tty->print_cr("Running internal VM tests");
+    run_unit_test(TestReservedSpace_test());
+    run_unit_test(TestReserveMemorySpecial_test());
     run_unit_test(GlobalDefinitions::test_globals());
     run_unit_test(GCTimerAllTest::all());
     run_unit_test(arrayOopDesc::test_max_array_length());

src/share/vm/runtime/globals.hpp

@@ -1933,6 +1933,9 @@ class CommandLineFlags {
   notproduct(bool, ExecuteInternalVMTests, false,                           \
           "Enable execution of internal VM tests.")                         \
                                                                             \
+  notproduct(bool, VerboseInternalVMTests, false,                           \
+          "Turn on logging for internal VM tests.")                         \
+                                                                            \
   product_pd(bool, UseTLAB, "Use thread-local object allocation")           \
                                                                             \
   product_pd(bool, ResizeTLAB,                                              \

src/share/vm/runtime/os.hpp

@@ -328,8 +328,8 @@ class os: AllStatic {
 
   static char*  non_memory_address_word();
   // reserve, commit and pin the entire memory region
-  static char*  reserve_memory_special(size_t size, char* addr = NULL,
-                bool executable = false);
+  static char*  reserve_memory_special(size_t size, size_t alignment,
+                                       char* addr, bool executable);
   static bool   release_memory_special(char* addr, size_t bytes);
   static void   large_page_init();
   static size_t large_page_size();

src/share/vm/runtime/virtualspace.cpp

@@ -42,8 +42,19 @@
 
 
 // ReservedSpace
+
+// Dummy constructor
+ReservedSpace::ReservedSpace() : _base(NULL), _size(0), _noaccess_prefix(0),
+    _alignment(0), _special(false), _executable(false) {
+}
+
 ReservedSpace::ReservedSpace(size_t size) {
-  initialize(size, 0, false, NULL, 0, false);
+  size_t page_size = os::page_size_for_region(size, size, 1);
+  bool large_pages = page_size != (size_t)os::vm_page_size();
+  // Don't force the alignment to be large page aligned,
+  // since that will waste memory.
+  size_t alignment = os::vm_allocation_granularity();
+  initialize(size, alignment, large_pages, NULL, 0, false);
 }
 
 ReservedSpace::ReservedSpace(size_t size, size_t alignment,
@@ -129,16 +140,18 @@ void ReservedSpace::initialize(size_t size, size_t alignment, bool large,
 
   if (special) {
 
-    base = os::reserve_memory_special(size, requested_address, executable);
+    base = os::reserve_memory_special(size, alignment, requested_address, executable);
 
     if (base != NULL) {
       if (failed_to_reserve_as_requested(base, requested_address, size, true)) {
         // OS ignored requested address. Try different address.
         return;
       }
-      // Check alignment constraints
+      // Check alignment constraints.
       assert((uintptr_t) base % alignment == 0,
-             "Large pages returned a non-aligned address");
+             err_msg("Large pages returned a non-aligned address, base: "
+                 PTR_FORMAT " alignment: " PTR_FORMAT,
+                 base, (void*)(uintptr_t)alignment));
       _special = true;
     } else {
       // failed; try to reserve regular memory below
@@ -715,4 +728,188 @@ void VirtualSpace::print() {
   tty->print_cr(" - [low_b, high_b]: [" INTPTR_FORMAT ", " INTPTR_FORMAT "]",  low_boundary(), high_boundary());
 }
 
+
+/////////////// Unit tests ///////////////
+
+#ifndef PRODUCT
+
+#define test_log(...) \
+  do {\
+    if (VerboseInternalVMTests) { \
+      tty->print_cr(__VA_ARGS__); \
+      tty->flush(); \
+    }\
+  } while (false)
+
+class TestReservedSpace : AllStatic {
+ public:
+  static void small_page_write(void* addr, size_t size) {
+    size_t page_size = os::vm_page_size();
+
+    char* end = (char*)addr + size;
+    for (char* p = (char*)addr; p < end; p += page_size) {
+      *p = 1;
+    }
+  }
+
+  static void release_memory_for_test(ReservedSpace rs) {
+    if (rs.special()) {
+      guarantee(os::release_memory_special(rs.base(), rs.size()), "Shouldn't fail");
+    } else {
+      guarantee(os::release_memory(rs.base(), rs.size()), "Shouldn't fail");
+    }
+  }
+
+  static void test_reserved_space1(size_t size, size_t alignment) {
+    test_log("test_reserved_space1(%p)", (void*) (uintptr_t) size);
+
+    assert(is_size_aligned(size, alignment), "Incorrect input parameters");
+
+    ReservedSpace rs(size,          // size
+                     alignment,     // alignment
+                     UseLargePages, // large
+                     NULL,          // requested_address
+                     0);            // noacces_prefix
+
+    test_log(" rs.special() == %d", rs.special());
+
+    assert(rs.base() != NULL, "Must be");
+    assert(rs.size() == size, "Must be");
+
+    assert(is_ptr_aligned(rs.base(), alignment), "aligned sizes should always give aligned addresses");
+    assert(is_size_aligned(rs.size(), alignment), "aligned sizes should always give aligned addresses");
+
+    if (rs.special()) {
+      small_page_write(rs.base(), size);
+    }
+
+    release_memory_for_test(rs);
+  }
+
+  static void test_reserved_space2(size_t size) {
+    test_log("test_reserved_space2(%p)", (void*)(uintptr_t)size);
+
+    assert(is_size_aligned(size, os::vm_allocation_granularity()), "Must be at least AG aligned");
+
+    ReservedSpace rs(size);
+
+    test_log(" rs.special() == %d", rs.special());
+
+    assert(rs.base() != NULL, "Must be");
+    assert(rs.size() == size, "Must be");
+
+    if (rs.special()) {
+      small_page_write(rs.base(), size);
+    }
+
+    release_memory_for_test(rs);
+  }
+
+  static void test_reserved_space3(size_t size, size_t alignment, bool maybe_large) {
+    test_log("test_reserved_space3(%p, %p, %d)",
+        (void*)(uintptr_t)size, (void*)(uintptr_t)alignment, maybe_large);
+
+    assert(is_size_aligned(size, os::vm_allocation_granularity()), "Must be at least AG aligned");
+    assert(is_size_aligned(size, alignment), "Must be at least aligned against alignment");
+
+    bool large = maybe_large && UseLargePages && size >= os::large_page_size();
+
+    ReservedSpace rs(size, alignment, large, false);
+
+    test_log(" rs.special() == %d", rs.special());
+
+    assert(rs.base() != NULL, "Must be");
+    assert(rs.size() == size, "Must be");
+
+    if (rs.special()) {
+      small_page_write(rs.base(), size);
+    }
+
+    release_memory_for_test(rs);
+  }
+
+
+  static void test_reserved_space1() {
+    size_t size = 2 * 1024 * 1024;
+    size_t ag   = os::vm_allocation_granularity();
+
+    test_reserved_space1(size,      ag);
+    test_reserved_space1(size * 2,  ag);
+    test_reserved_space1(size * 10, ag);
+  }
+
+  static void test_reserved_space2() {
+    size_t size = 2 * 1024 * 1024;
+    size_t ag = os::vm_allocation_granularity();
+
+    test_reserved_space2(size * 1);
+    test_reserved_space2(size * 2);
+    test_reserved_space2(size * 10);
+    test_reserved_space2(ag);
+    test_reserved_space2(size - ag);
+    test_reserved_space2(size);
+    test_reserved_space2(size + ag);
+    test_reserved_space2(size * 2);
+    test_reserved_space2(size * 2 - ag);
+    test_reserved_space2(size * 2 + ag);
+    test_reserved_space2(size * 3);
+    test_reserved_space2(size * 3 - ag);
+    test_reserved_space2(size * 3 + ag);
+    test_reserved_space2(size * 10);
+    test_reserved_space2(size * 10 + size / 2);
+  }
+
+  static void test_reserved_space3() {
+    size_t ag = os::vm_allocation_granularity();
+
+    test_reserved_space3(ag,      ag    , false);
+    test_reserved_space3(ag * 2,  ag    , false);
+    test_reserved_space3(ag * 3,  ag    , false);
+    test_reserved_space3(ag * 2,  ag * 2, false);
+    test_reserved_space3(ag * 4,  ag * 2, false);
+    test_reserved_space3(ag * 8,  ag * 2, false);
+    test_reserved_space3(ag * 4,  ag * 4, false);
+    test_reserved_space3(ag * 8,  ag * 4, false);
+    test_reserved_space3(ag * 16, ag * 4, false);
+
+    if (UseLargePages) {
+      size_t lp = os::large_page_size();
+
+      // Without large pages
+      test_reserved_space3(lp,     ag * 4, false);
+      test_reserved_space3(lp * 2, ag * 4, false);
+      test_reserved_space3(lp * 4, ag * 4, false);
+      test_reserved_space3(lp,     lp    , false);
+      test_reserved_space3(lp * 2, lp    , false);
+      test_reserved_space3(lp * 3, lp    , false);
+      test_reserved_space3(lp * 2, lp * 2, false);
+      test_reserved_space3(lp * 4, lp * 2, false);
+      test_reserved_space3(lp * 8, lp * 2, false);
+
+      // With large pages
+      test_reserved_space3(lp, ag * 4    , true);
+      test_reserved_space3(lp * 2, ag * 4, true);
+      test_reserved_space3(lp * 4, ag * 4, true);
+      test_reserved_space3(lp, lp        , true);
+      test_reserved_space3(lp * 2, lp    , true);
+      test_reserved_space3(lp * 3, lp    , true);
+      test_reserved_space3(lp * 2, lp * 2, true);
+      test_reserved_space3(lp * 4, lp * 2, true);
+      test_reserved_space3(lp * 8, lp * 2, true);
+    }
+  }
+
+  static void test_reserved_space() {
+    test_reserved_space1();
+    test_reserved_space2();
+    test_reserved_space3();
+  }
+};
+
+void TestReservedSpace_test() {
+  TestReservedSpace::test_reserved_space();
+}
+
+#endif // PRODUCT
+
 #endif

src/share/vm/runtime/virtualspace.hpp

@@ -53,6 +53,7 @@ class ReservedSpace VALUE_OBJ_CLASS_SPEC {
 
  public:
   // Constructor
+  ReservedSpace();
   ReservedSpace(size_t size);
   ReservedSpace(size_t size, size_t alignment, bool large,
                 char* requested_address = NULL,

src/share/vm/services/memTracker.hpp

@@ -87,6 +87,8 @@ class MemTracker : AllStatic {
         MEMFLAGS flags, address pc = 0, Thread* thread = NULL) { }
    static inline void record_virtual_memory_commit(address addr, size_t size,
         address pc = 0, Thread* thread = NULL) { }
+   static inline void record_virtual_memory_release(address addr, size_t size,
+        Thread* thread = NULL) { }
    static inline void record_virtual_memory_type(address base, MEMFLAGS flags,
         Thread* thread = NULL) { }
    static inline Tracker get_realloc_tracker() { return _tkr; }
@@ -372,6 +374,13 @@ class MemTracker : AllStatic {
     tkr.record(addr, size, flags, pc);
   }
 
+  static inline void record_virtual_memory_release(address addr, size_t size,
+      Thread* thread = NULL) {
+    if (is_on()) {
+      Tracker tkr(Tracker::Release, thread);
+      tkr.record(addr, size);
+    }
+  }
 
   // record memory type on virtual memory base address
   static inline void record_virtual_memory_type(address base, MEMFLAGS flags,

src/share/vm/utilities/globalDefinitions.hpp

@@ -402,6 +402,14 @@ const jlong CompressedKlassPointersBase = NOT_LP64(0) LP64_ONLY(CONST64(0x800000
 
 #define align_size_up_(size, alignment) (((size) + ((alignment) - 1)) & ~((alignment) - 1))
 
+inline bool is_size_aligned(size_t size, size_t alignment) {
+  return align_size_up_(size, alignment) == size;
+}
+
+inline bool is_ptr_aligned(void* ptr, size_t alignment) {
+  return align_size_up_((intptr_t)ptr, (intptr_t)alignment) == (intptr_t)ptr;
+}
+
 inline intptr_t align_size_up(intptr_t size, intptr_t alignment) {
   return align_size_up_(size, alignment);
 }
@@ -414,6 +422,14 @@ inline intptr_t align_size_down(intptr_t size, intptr_t alignment) {
 
 #define is_size_aligned_(size, alignment) ((size) == (align_size_up_(size, alignment)))
 
+inline void* align_ptr_up(void* ptr, size_t alignment) {
+  return (void*)align_size_up((intptr_t)ptr, (intptr_t)alignment);
+}
+
+inline void* align_ptr_down(void* ptr, size_t alignment) {
+  return (void*)align_size_down((intptr_t)ptr, (intptr_t)alignment);
+}
+
 // Align objects by rounding up their size, in HeapWord units.
 
 #define align_object_size_(size) align_size_up_(size, MinObjAlignment)