JEP387 review feedback round 2

src/hotspot/share/gc/shared/jvmFlagConstraintsGC.hpp

@@ -56,7 +56,6 @@
                                                                \
  f(uintx,  MaxGCPauseMillisConstraintFunc)                     \
  f(uintx,  GCPauseIntervalMillisConstraintFunc)                \
- f(size_t, InitialBootClassLoaderMetaspaceSizeConstraintFunc)  \
  f(size_t, MinHeapSizeConstraintFunc)                          \
  f(size_t, InitialHeapSizeConstraintFunc)                      \
  f(size_t, MaxHeapSizeConstraintFunc)                          \

src/hotspot/share/memory/metaspace.cpp

@@ -29,16 +29,16 @@
 #include "logging/log.hpp"
 #include "logging/logStream.hpp"
 #include "memory/filemap.hpp"
+#include "memory/metaspace/chunkHeaderPool.hpp"
+#include "memory/metaspace/chunkManager.hpp"
+#include "memory/metaspace/commitLimiter.hpp"
+#include "memory/metaspace/metaspaceCommon.hpp"
+#include "memory/metaspace/metaspaceContext.hpp"
+#include "memory/metaspace/metaspaceReporter.hpp"
+#include "memory/metaspace/metaspaceSettings.hpp"
 #include "memory/metaspace/metaspaceSizesSnapshot.hpp"
-#include "memory/metaspace/msChunkHeaderPool.hpp"
-#include "memory/metaspace/msChunkManager.hpp"
-#include "memory/metaspace/msCommitLimiter.hpp"
-#include "memory/metaspace/msCommon.hpp"
-#include "memory/metaspace/msContext.hpp"
-#include "memory/metaspace/msReport.hpp"
-#include "memory/metaspace/msRunningCounters.hpp"
-#include "memory/metaspace/msSettings.hpp"
-#include "memory/metaspace/msVirtualSpaceList.hpp"
+#include "memory/metaspace/runningCounters.hpp"
+#include "memory/metaspace/virtualSpaceList.hpp"
 #include "memory/metaspace.hpp"
 #include "memory/metaspaceShared.hpp"
 #include "memory/metaspaceTracer.hpp"

src/hotspot/share/memory/metaspace/msAllocationGuard.hpp → src/hotspot/share/memory/metaspace/allocationGuard.hpp

@@ -23,12 +23,11 @@
  *
  */
 
-#ifndef SHARE_MEMORY_METASPACE_MSALLOCATIONGUARD_HPP
-#define SHARE_MEMORY_METASPACE_MSALLOCATIONGUARD_HPP
+#ifndef SHARE_MEMORY_METASPACE_ALLOCATIONGUARD_HPP
+#define SHARE_MEMORY_METASPACE_ALLOCATIONGUARD_HPP
 
 #include "memory/allocation.hpp"
-#include "memory/metaspace/msChunklevel.hpp"
-#include "utilities/debug.hpp"
+#include "memory/metaspace/chunklevel.hpp"
 #include "utilities/globalDefinitions.hpp"
 
 // In Debug builds, Metadata in Metaspace can be optionally guarded - enclosed in canaries -
@@ -90,10 +89,8 @@ struct Prefix {
     return (MetaWord*)(this + 1);
   }
 
-  void check() const {
-    assert(_mark == EyeCatcher, "Corrupt block: missing eyecatcher (at " PTR_FORMAT ").", p2i(this));
-    assert(_word_size > 0 && _word_size < chunklevel::MAX_CHUNK_WORD_SIZE,
-           "Corrupt block: invalid size " SIZE_FORMAT " (at " PTR_FORMAT ").", _word_size, p2i(this));
+  bool is_valid() const {
+    return _mark == EyeCatcher && _word_size > 0 && _word_size < chunklevel::MAX_CHUNK_WORD_SIZE;
   }
 
 };
@@ -116,4 +113,4 @@ inline MetaWord* establish_prefix(MetaWord* p_raw, size_t raw_word_size) {
 
 } // namespace metaspace
 
-#endif // SHARE_MEMORY_METASPACE_MSALLOCATIONGUARD_HPP
+#endif // SHARE_MEMORY_METASPACE_ALLOCATIONGUARD_HPP

src/hotspot/share/memory/metaspace/msBinList.hpp → src/hotspot/share/memory/metaspace/binList.hpp

@@ -23,11 +23,11 @@
  *
  */
 
-#ifndef SHARE_MEMORY_METASPACE_MSBINLIST_HPP
-#define SHARE_MEMORY_METASPACE_MSBINLIST_HPP
+#ifndef SHARE_MEMORY_METASPACE_BINLIST_HPP
+#define SHARE_MEMORY_METASPACE_BINLIST_HPP
 
-#include "memory/metaspace/msCommon.hpp"
-#include "memory/metaspace/msCounter.hpp"
+#include "memory/metaspace/counters.hpp"
+#include "memory/metaspace/metaspaceCommon.hpp"
 #include "utilities/align.hpp"
 #include "utilities/debug.hpp"
 #include "utilities/globalDefinitions.hpp"
@@ -222,4 +222,4 @@ typedef BinListImpl<2, 32> BinList32;
 
 } // namespace metaspace
 
-#endif // SHARE_MEMORY_METASPACE_MSBINLIST_HPP
+#endif // SHARE_MEMORY_METASPACE_BINLIST_HPP

src/hotspot/share/memory/metaspace/msBlockTree.cpp → src/hotspot/share/memory/metaspace/blockTree.cpp

@@ -25,7 +25,7 @@
 
 #include "precompiled.hpp"
 
-#include "memory/metaspace/msBlockTree.hpp"
+#include "memory/metaspace/blockTree.hpp"
 #include "memory/resourceArea.hpp"
 #include "utilities/debug.hpp"
 #include "utilities/globalDefinitions.hpp"

src/hotspot/share/memory/metaspace/msBlockTree.hpp → src/hotspot/share/memory/metaspace/blockTree.hpp

@@ -23,12 +23,12 @@
  *
  */
 
-#ifndef SHARE_MEMORY_METASPACE_MSBLOCKTREE_HPP
-#define SHARE_MEMORY_METASPACE_MSBLOCKTREE_HPP
+#ifndef SHARE_MEMORY_METASPACE_BLOCKTREE_HPP
+#define SHARE_MEMORY_METASPACE_BLOCKTREE_HPP
 
 #include "memory/allocation.hpp"
-#include "memory/metaspace/msChunklevel.hpp"
-#include "memory/metaspace/msCounter.hpp"
+#include "memory/metaspace/chunklevel.hpp"
+#include "memory/metaspace/counters.hpp"
 #include "utilities/debug.hpp"
 #include "utilities/globalDefinitions.hpp"
 
@@ -404,4 +404,4 @@ class BlockTree: public CHeapObj<mtMetaspace> {
 
 } // namespace metaspace
 
-#endif // SHARE_MEMORY_METASPACE_MSBLOCKTREE_HPP
+#endif // SHARE_MEMORY_METASPACE_BLOCKTREE_HPP

src/hotspot/share/memory/metaspace/msChunkHeaderPool.cpp → src/hotspot/share/memory/metaspace/chunkHeaderPool.cpp

@@ -24,7 +24,7 @@
  */
 
 #include "precompiled.hpp"
-#include "memory/metaspace/msChunkHeaderPool.hpp"
+#include "memory/metaspace/chunkHeaderPool.hpp"
 #include "runtime/os.hpp"
 #include "utilities/debug.hpp"
 #include "utilities/globalDefinitions.hpp"

src/hotspot/share/memory/metaspace/msChunkHeaderPool.hpp → src/hotspot/share/memory/metaspace/chunkHeaderPool.hpp

@@ -23,13 +23,13 @@
  *
  */
 
-#ifndef SHARE_MEMORY_METASPACE_MSCHUNKHEADERPOOL_HPP
-#define SHARE_MEMORY_METASPACE_MSCHUNKHEADERPOOL_HPP
+#ifndef SHARE_MEMORY_METASPACE_CHUNKHEADERPOOL_HPP
+#define SHARE_MEMORY_METASPACE_CHUNKHEADERPOOL_HPP
 
 #include "memory/allocation.hpp"
-#include "memory/metaspace/msCounter.hpp"
-#include "memory/metaspace/msMetachunk.hpp"
-#include "memory/metaspace/msMetachunkList.hpp"
+#include "memory/metaspace/counters.hpp"
+#include "memory/metaspace/metachunk.hpp"
+#include "memory/metaspace/metachunkList.hpp"
 #include "utilities/debug.hpp"
 #include "utilities/globalDefinitions.hpp"
 
@@ -142,4 +142,4 @@ class ChunkHeaderPool : public CHeapObj<mtMetaspace> {
 
 } // namespace metaspace
 
-#endif // SHARE_MEMORY_METASPACE_MSCHUNKHEADERPOOL_HPP
+#endif // SHARE_MEMORY_METASPACE_CHUNKHEADERPOOL_HPP

src/hotspot/share/memory/metaspace/msChunkManager.cpp → src/hotspot/share/memory/metaspace/chunkManager.cpp

@@ -27,16 +27,16 @@
 
 #include "logging/log.hpp"
 #include "logging/logStream.hpp"
-#include "memory/metaspace/msArenaGrowthPolicy.hpp"
-#include "memory/metaspace/msChunkManager.hpp"
-#include "memory/metaspace/msCommon.hpp"
-#include "memory/metaspace/msContext.hpp"
-#include "memory/metaspace/msInternalStats.hpp"
-#include "memory/metaspace/msMetachunk.hpp"
-#include "memory/metaspace/msSettings.hpp"
-#include "memory/metaspace/msStatistics.hpp"
-#include "memory/metaspace/msVirtualSpaceList.hpp"
-#include "memory/metaspace/msVirtualSpaceNode.hpp"
+#include "memory/metaspace/chunkManager.hpp"
+#include "memory/metaspace/internalStats.hpp"
+#include "memory/metaspace/metaspaceArenaGrowthPolicy.hpp"
+#include "memory/metaspace/metaspaceCommon.hpp"
+#include "memory/metaspace/metaspaceContext.hpp"
+#include "memory/metaspace/metachunk.hpp"
+#include "memory/metaspace/metaspaceSettings.hpp"
+#include "memory/metaspace/metaspaceStatistics.hpp"
+#include "memory/metaspace/virtualSpaceList.hpp"
+#include "memory/metaspace/virtualSpaceNode.hpp"
 #include "runtime/mutexLocker.hpp"
 #include "utilities/debug.hpp"
 #include "utilities/globalDefinitions.hpp"
@@ -369,11 +369,22 @@ void ChunkManager::purge() {
   const size_t committed_before = _vslist->committed_words();
   int num_nodes_purged = 0;
 
-  // 1) purge virtual space list
+  // We purge to return unused memory to the Operating System. We do this in
+  //  two independent steps.
+
+  // 1) We purge the virtual space list: any memory mappings which are
+  //   completely deserted can be potentially unmapped. We iterate over the list
+  //   of mappings (VirtualSpaceList::purge) and delete every node whose memory
+  //   only contains free chunks. Deleting that node includes unmapping its memory,
+  //   so all chunk vanish automatically.
+  //   Of course we need to remove the chunk headers of those vanished chunks from
+  //   the ChunkManager freelist.
   num_nodes_purged = _vslist->purge(&_chunks);
   InternalStats::inc_num_purges();
 
-  // 2) uncommit free chunks
+  // 2) Since (1) is rather ineffective - it is rare that a whole node only contains
+  //   free chunks - we now iterate over all remaining free chunks and
+  //   and uncommit those which can be uncommitted (>= commit granule size).
   if (Settings::uncommit_free_chunks()) {
     const chunklevel_t max_level =
         chunklevel::level_fitting_word_size(Settings::commit_granule_words());

src/hotspot/share/memory/metaspace/msChunkManager.hpp → src/hotspot/share/memory/metaspace/chunkManager.hpp

@@ -23,14 +23,14 @@
  *
  */
 
-#ifndef SHARE_MEMORY_METASPACE_MSCHUNKMANAGER_HPP
-#define SHARE_MEMORY_METASPACE_MSCHUNKMANAGER_HPP
+#ifndef SHARE_MEMORY_METASPACE_CHUNKMANAGER_HPP
+#define SHARE_MEMORY_METASPACE_CHUNKMANAGER_HPP
 
 #include "memory/allocation.hpp"
-#include "memory/metaspace/msChunklevel.hpp"
-#include "memory/metaspace/msCounter.hpp"
-#include "memory/metaspace/msFreeChunkList.hpp"
-#include "memory/metaspace/msMetachunk.hpp"
+#include "memory/metaspace/chunklevel.hpp"
+#include "memory/metaspace/counters.hpp"
+#include "memory/metaspace/freeChunkList.hpp"
+#include "memory/metaspace/metachunk.hpp"
 
 namespace metaspace {
 
@@ -185,4 +185,4 @@ class ChunkManager : public CHeapObj<mtMetaspace> {
 
 } // namespace metaspace
 
-#endif // SHARE_MEMORY_METASPACE_MSCHUNKMANAGER_HPP
+#endif // SHARE_MEMORY_METASPACE_CHUNKMANAGER_HPP

src/hotspot/share/memory/metaspace/msChunklevel.cpp → src/hotspot/share/memory/metaspace/chunklevel.cpp

@@ -24,7 +24,7 @@
  */
 
 #include "precompiled.hpp"
-#include "memory/metaspace/msChunklevel.hpp"
+#include "memory/metaspace/chunklevel.hpp"
 #include "utilities/debug.hpp"
 #include "utilities/globalDefinitions.hpp"
 #include "utilities/ostream.hpp"

src/hotspot/share/memory/metaspace/msChunklevel.hpp → src/hotspot/share/memory/metaspace/chunklevel.hpp

@@ -23,8 +23,8 @@
  *
  */
 
-#ifndef SHARE_MEMORY_METASPACE_MSCHUNKLEVEL_HPP
-#define SHARE_MEMORY_METASPACE_MSCHUNKLEVEL_HPP
+#ifndef SHARE_MEMORY_METASPACE_CHUNKLEVEL_HPP
+#define SHARE_MEMORY_METASPACE_CHUNKLEVEL_HPP
 
 #include "utilities/globalDefinitions.hpp"
 
@@ -127,4 +127,4 @@ void print_chunk_size(outputStream* st, chunklevel_t lvl);
 
 } // namespace metaspace
 
-#endif // SHARE_MEMORY_METASPACE_MSCHUNKLEVEL_HPP
+#endif // SHARE_MEMORY_METASPACE_CHUNKLEVEL_HPP

src/hotspot/share/memory/metaspace/msClassLoaderMetaspace.cpp → src/hotspot/share/memory/metaspace/classLoaderMetaspace.cpp

@@ -26,13 +26,13 @@
 #include "precompiled.hpp"
 
 #include "logging/log.hpp"
-#include "memory/metaspace/msArena.hpp"
-#include "memory/metaspace/msArenaGrowthPolicy.hpp"
-#include "memory/metaspace/msChunkManager.hpp"
-#include "memory/metaspace/msInternalStats.hpp"
-#include "memory/metaspace/msRunningCounters.hpp"
-#include "memory/metaspace/msSettings.hpp"
-#include "memory/metaspace/msStatistics.hpp"
+#include "memory/metaspace/chunkManager.hpp"
+#include "memory/metaspace/internalStats.hpp"
+#include "memory/metaspace/metaspaceArena.hpp"
+#include "memory/metaspace/metaspaceArenaGrowthPolicy.hpp"
+#include "memory/metaspace/metaspaceSettings.hpp"
+#include "memory/metaspace/metaspaceStatistics.hpp"
+#include "memory/metaspace/runningCounters.hpp"
 #include "memory/metaspace.hpp"
 #include "memory/metaspaceTracer.hpp"
 #include "runtime/atomic.hpp"

src/hotspot/share/memory/metaspace/msCommitLimiter.cpp → src/hotspot/share/memory/metaspace/commitLimiter.cpp

@@ -25,7 +25,7 @@
 
 #include "precompiled.hpp"
 
-#include "memory/metaspace/msCommitLimiter.hpp"
+#include "memory/metaspace/commitLimiter.hpp"
 #include "memory/metaspace.hpp"
 #include "utilities/debug.hpp"
 #include "utilities/globalDefinitions.hpp"

src/hotspot/share/memory/metaspace/msCommitLimiter.hpp → src/hotspot/share/memory/metaspace/commitLimiter.hpp

@@ -23,11 +23,11 @@
  *
  */
 
-#ifndef SHARE_MEMORY_METASPACE_MSCOMMITLIMITER_HPP
-#define SHARE_MEMORY_METASPACE_MSCOMMITLIMITER_HPP
+#ifndef SHARE_MEMORY_METASPACE_COMMITLIMITER_HPP
+#define SHARE_MEMORY_METASPACE_COMMITLIMITER_HPP
 
 #include "memory/allocation.hpp"
-#include "memory/metaspace/msCounter.hpp"
+#include "memory/metaspace/counters.hpp"
 
 namespace metaspace {
 
@@ -81,4 +81,4 @@ class CommitLimiter : public CHeapObj<mtMetaspace> {
 
 } // namespace metaspace
 
-#endif // SHARE_MEMORY_METASPACE_MSCOMMITLIMITER_HPP
+#endif // SHARE_MEMORY_METASPACE_COMMITLIMITER_HPP

src/hotspot/share/memory/metaspace/msCommitMask.cpp → src/hotspot/share/memory/metaspace/commitMask.cpp

@@ -25,9 +25,9 @@
 
 #include "precompiled.hpp"
 
-#include "memory/metaspace/msCommitMask.hpp"
-#include "memory/metaspace/msCommon.hpp"
-#include "memory/metaspace/msSettings.hpp"
+#include "memory/metaspace/commitMask.hpp"
+#include "memory/metaspace/metaspaceCommon.hpp"
+#include "memory/metaspace/metaspaceSettings.hpp"
 #include "runtime/stubRoutines.hpp"
 
 #include "utilities/align.hpp"

src/hotspot/share/memory/metaspace/msCommitMask.hpp → src/hotspot/share/memory/metaspace/commitMask.hpp

@@ -23,8 +23,8 @@
  *
  */
 
-#ifndef SHARE_MEMORY_METASPACE_MSCOMMITMASK_HPP
-#define SHARE_MEMORY_METASPACE_MSCOMMITMASK_HPP
+#ifndef SHARE_MEMORY_METASPACE_COMMITMASK_HPP
+#define SHARE_MEMORY_METASPACE_COMMITMASK_HPP
 
 #include "utilities/debug.hpp"
 #include "utilities/bitMap.hpp"
@@ -175,4 +175,4 @@ class CommitMask : public CHeapBitMap {
 
 } // namespace metaspace
 
-#endif // SHARE_MEMORY_METASPACE_MSCOMMITMASK_HPP
+#endif // SHARE_MEMORY_METASPACE_COMMITMASK_HPP

src/hotspot/share/memory/metaspace/msCounter.hpp → src/hotspot/share/memory/metaspace/counters.hpp

@@ -23,8 +23,8 @@
  *
  */
 
-#ifndef SHARE_MEMORY_METASPACE_MSCOUNTER_HPP
-#define SHARE_MEMORY_METASPACE_MSCOUNTER_HPP
+#ifndef SHARE_MEMORY_METASPACE_COUNTERS_HPP
+#define SHARE_MEMORY_METASPACE_COUNTERS_HPP
 
 #include "metaprogramming/isSigned.hpp"
 #include "runtime/atomic.hpp"
@@ -179,5 +179,5 @@ typedef AbstractMemoryRangeCounter<unsigned, size_t> MemRangeCounter;
 
 } // namespace metaspace
 
-#endif // SHARE_MEMORY_METASPACE_MSCOUNTER_HPP
+#endif // SHARE_MEMORY_METASPACE_COUNTERS_HPP
 

src/hotspot/share/memory/metaspace/msFreeBlocks.cpp → src/hotspot/share/memory/metaspace/freeBlocks.cpp

@@ -24,7 +24,7 @@
  */
 
 #include "precompiled.hpp"
-#include "memory/metaspace/msFreeBlocks.hpp"
+#include "memory/metaspace/freeBlocks.hpp"
 #include "utilities/globalDefinitions.hpp"
 #include "utilities/debug.hpp"
 

src/hotspot/share/memory/metaspace/msFreeBlocks.hpp → src/hotspot/share/memory/metaspace/freeBlocks.hpp

@@ -23,14 +23,14 @@
  *
  */
 
-#ifndef SHARE_MEMORY_METASPACE_MSFREEBLOCKS_HPP
-#define SHARE_MEMORY_METASPACE_MSFREEBLOCKS_HPP
+#ifndef SHARE_MEMORY_METASPACE_FREEBLOCKS_HPP
+#define SHARE_MEMORY_METASPACE_FREEBLOCKS_HPP
 
 #include "memory/allocation.hpp"
 
-#include "memory/metaspace/msBinList.hpp"
-#include "memory/metaspace/msBlockTree.hpp"
-#include "memory/metaspace/msCounter.hpp"
+#include "memory/metaspace/binList.hpp"
+#include "memory/metaspace/blockTree.hpp"
+#include "memory/metaspace/counters.hpp"
 
 #include "utilities/debug.hpp"
 #include "utilities/globalDefinitions.hpp"
@@ -112,4 +112,4 @@ class FreeBlocks : public CHeapObj<mtMetaspace> {
 
 } // namespace metaspace
 
-#endif // SHARE_MEMORY_METASPACE_MSFREEBLOCKS_HPP
+#endif // SHARE_MEMORY_METASPACE_FREEBLOCKS_HPP