8307958: Metaspace verification is slow causing extreme class unloading times

Reviewed-by: stuefe, coleenp

Author: xmas92

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

@@ -49,7 +49,7 @@ namespace metaspace {
 // Return a single chunk to the freelist and adjust accounting. No merge is attempted.
 void ChunkManager::return_chunk_simple_locked(Metachunk* c) {
   assert_lock_strong(Metaspace_lock);
-  DEBUG_ONLY(c->verify());
+  SOMETIMES(c->verify();)
   _chunks.add(c);
   c->reset_used_words();
   // Tracing
@@ -82,7 +82,7 @@ void ChunkManager::split_chunk_and_add_splinters(Metachunk* c, chunklevel_t targ
   assert(c->prev() == nullptr && c->next() == nullptr, "Chunk must be outside of any list.");
 
   DEBUG_ONLY(chunklevel::check_valid_level(target_level);)
-  DEBUG_ONLY(c->verify();)
+  SOMETIMES(c->verify();)
 
   UL2(debug, "splitting chunk " METACHUNK_FORMAT " to " CHKLVL_FORMAT ".",
       METACHUNK_FORMAT_ARGS(c), target_level);
@@ -101,8 +101,8 @@ void ChunkManager::split_chunk_and_add_splinters(Metachunk* c, chunklevel_t targ
   } else {
     assert(c->committed_words() == committed_words_before, "Sanity");
   }
-  c->verify();
-  verify_locked();
+  SOMETIMES(c->verify();)
+  SOMETIMES(verify_locked();)
   SOMETIMES(c->vsnode()->verify_locked();)
 #endif
   InternalStats::inc_num_chunk_splits();
@@ -136,7 +136,7 @@ Metachunk* ChunkManager::get_chunk(chunklevel_t preferred_level, chunklevel_t ma
 //   This may be either the GC threshold or MaxMetaspaceSize.
 Metachunk* ChunkManager::get_chunk_locked(chunklevel_t preferred_level, chunklevel_t max_level, size_t min_committed_words) {
   assert_lock_strong(Metaspace_lock);
-  DEBUG_ONLY(verify_locked();)
+  SOMETIMES(verify_locked();)
   DEBUG_ONLY(chunklevel::check_valid_level(max_level);)
   DEBUG_ONLY(chunklevel::check_valid_level(preferred_level);)
 
@@ -255,8 +255,8 @@ void ChunkManager::return_chunk(Metachunk* c) {
 void ChunkManager::return_chunk_locked(Metachunk* c) {
   assert_lock_strong(Metaspace_lock);
   UL2(debug, ": returning chunk " METACHUNK_FORMAT ".", METACHUNK_FORMAT_ARGS(c));
-  DEBUG_ONLY(c->verify();)
-  assert(contains_chunk(c) == false, "A chunk to be added to the freelist must not be in the freelist already.");
+  SOMETIMES(c->verify();)
+  ASSERT_SOMETIMES(contains_chunk(c) == false, "A chunk to be added to the freelist must not be in the freelist already.");
   assert(c->is_in_use() || c->is_free(), "Unexpected chunk state");
   assert(!c->in_list(), "Remove from list first");
 
@@ -272,15 +272,15 @@ void ChunkManager::return_chunk_locked(Metachunk* c) {
 
   if (merged != nullptr) {
     InternalStats::inc_num_chunk_merges();
-    DEBUG_ONLY(merged->verify());
+    SOMETIMES(merged->verify();)
     // We did merge chunks and now have a bigger chunk.
     assert(merged->level() < orig_lvl, "Sanity");
     UL2(debug, "merged into chunk " METACHUNK_FORMAT ".", METACHUNK_FORMAT_ARGS(merged));
     c = merged;
   }
 
   return_chunk_simple_locked(c);
-  DEBUG_ONLY(verify_locked();)
+  SOMETIMES(verify_locked();)
   SOMETIMES(c->vsnode()->verify_locked();)
   InternalStats::inc_num_chunks_returned_to_freelist();
 }
@@ -373,8 +373,8 @@ void ChunkManager::purge() {
       ls.cr();
     }
   }
-  DEBUG_ONLY(_vslist->verify_locked());
-  DEBUG_ONLY(verify_locked());
+  SOMETIMES(_vslist->verify_locked();)
+  SOMETIMES(verify_locked();)
 }
 
 // Convenience methods to return the global class-space chunkmanager

src/hotspot/share/memory/metaspace/freeChunkList.hpp

@@ -31,6 +31,7 @@
 #include "memory/metaspace/counters.hpp"
 #include "memory/metaspace/metachunk.hpp"
 #include "memory/metaspace/metachunkList.hpp"
+#include "memory/metaspace/metaspaceCommon.hpp"
 
 class outputStream;
 
@@ -102,7 +103,7 @@ class FreeChunkList {
 
   // Remove given chunk from anywhere in the list.
   Metachunk* remove(Metachunk* c) {
-    assert(contains(c), "Must be contained here");
+    ASSERT_SOMETIMES(contains(c), "Must be contained here");
     Metachunk* pred = c->prev();
     Metachunk* succ = c->next();
     if (pred) {
@@ -124,7 +125,7 @@ class FreeChunkList {
   }
 
   void add(Metachunk* c) {
-    assert(contains(c) == false, "Chunk already in freelist");
+    ASSERT_SOMETIMES(contains(c) == false, "Chunk already in freelist");
     assert(_first == nullptr || _first->level() == c->level(),
            "List should only contains chunks of the same level.");
     // Uncommitted chunks go to the back, fully or partially committed to the front.

src/hotspot/share/memory/metaspace/metaspaceArena.cpp

@@ -129,9 +129,9 @@ MetaspaceArena::MetaspaceArena(ChunkManager* chunk_manager, const ArenaGrowthPol
 
 MetaspaceArena::~MetaspaceArena() {
 #ifdef ASSERT
-  verify();
+  SOMETIMES(verify();)
   if (Settings::use_allocation_guard()) {
-    verify_allocation_guards();
+    SOMETIMES(verify_allocation_guards();)
   }
 #endif
 
@@ -156,7 +156,7 @@ MetaspaceArena::~MetaspaceArena() {
       return_counter.count(), return_counter.total_size());
 
   _total_used_words_counter->decrement_by(return_counter.total_size());
-  DEBUG_ONLY(chunk_manager()->verify();)
+  SOMETIMES(chunk_manager()->verify();)
   delete _fbl;
   UL(debug, ": dies.");
 
@@ -368,7 +368,7 @@ void MetaspaceArena::deallocate_locked(MetaWord* p, size_t word_size) {
   size_t raw_word_size = get_raw_word_size_for_requested_word_size(word_size);
   add_allocation_to_fbl(p, raw_word_size);
 
-  DEBUG_ONLY(verify_locked();)
+  SOMETIMES(verify_locked();)
 }
 
 // Prematurely returns a metaspace allocation to the _block_freelists because it is not

src/hotspot/share/memory/metaspace/rootChunkArea.cpp

@@ -98,7 +98,7 @@ void RootChunkArea::split(chunklevel_t target_level, Metachunk* c, FreeChunkList
   //
 
   DEBUG_ONLY(check_pointer(c->base());)
-  DEBUG_ONLY(c->verify();)
+  SOMETIMES(c->verify();)
   assert(c->is_free(), "Can only split free chunks.");
 
   DEBUG_ONLY(chunklevel::check_valid_level(target_level));
@@ -139,8 +139,8 @@ void RootChunkArea::split(chunklevel_t target_level, Metachunk* c, FreeChunkList
 
   assert(c->level() == target_level, "Sanity");
 
-  DEBUG_ONLY(verify();)
-  DEBUG_ONLY(c->verify();)
+  SOMETIMES(verify();)
+  SOMETIMES(c->verify();)
 }
 
 // Given a chunk, attempt to merge it recursively with its neighboring chunks.
@@ -194,7 +194,7 @@ Metachunk* RootChunkArea::merge(Metachunk* c, FreeChunkListVector* freelists) {
   assert(!c->is_root_chunk(), "Cannot be merged further.");
   assert(c->is_free(), "Can only merge free chunks.");
 
-  DEBUG_ONLY(c->verify();)
+  SOMETIMES(c->verify();)
 
   log_trace(metaspace)("Attempting to merge chunk " METACHUNK_FORMAT ".", METACHUNK_FORMAT_ARGS(c));
 
@@ -208,7 +208,7 @@ Metachunk* RootChunkArea::merge(Metachunk* c, FreeChunkListVector* freelists) {
 
     // Note: this is either our buddy or a splinter of the buddy.
     Metachunk* const buddy = c->is_leader() ? c->next_in_vs() : c->prev_in_vs();
-    DEBUG_ONLY(buddy->verify();)
+    SOMETIMES(buddy->verify();)
 
     // A buddy chunk must be of the same or higher level (so, same size or smaller)
     // never be larger.
@@ -270,14 +270,14 @@ Metachunk* RootChunkArea::merge(Metachunk* c, FreeChunkListVector* freelists) {
       }
 
       result = c = leader;
-      DEBUG_ONLY(leader->verify();)
+      SOMETIMES(leader->verify();)
     }
   } while (!stop);
 
 #ifdef ASSERT
-  verify();
+  SOMETIMES(verify();)
   if (result != nullptr) {
-    result->verify();
+    SOMETIMES(result->verify();)
   }
 #endif // ASSERT
   return result;
@@ -299,15 +299,15 @@ bool RootChunkArea::attempt_enlarge_chunk(Metachunk* c, FreeChunkListVector* fre
   // There is no real reason for this limitation other than it is not
   // needed on free chunks since they should be merged already:
   assert(c->is_in_use(), "Can only enlarge in use chunks.");
-  DEBUG_ONLY(c->verify();)
+  SOMETIMES(c->verify();)
 
   if (!c->is_leader()) {
     return false;
   }
 
   // We are the leader, so the buddy must follow us.
   Metachunk* const buddy = c->next_in_vs();
-  DEBUG_ONLY(buddy->verify();)
+  SOMETIMES(buddy->verify();)
 
   // Of course buddy cannot be larger than us.
   assert(buddy->level() >= c->level(), "Sanity");
@@ -352,7 +352,7 @@ bool RootChunkArea::attempt_enlarge_chunk(Metachunk* c, FreeChunkListVector* fre
 
   log_debug(metaspace)("Enlarged chunk " METACHUNK_FULL_FORMAT ".", METACHUNK_FULL_FORMAT_ARGS(c));
 
-  DEBUG_ONLY(verify());
+  SOMETIMES(verify();)
   return true;
 }
 

src/hotspot/share/memory/metaspace/virtualSpaceNode.cpp

@@ -322,7 +322,7 @@ Metachunk* VirtualSpaceNode::allocate_root_chunk() {
     Metachunk* c = rca->alloc_root_chunk_header(this);
     assert(c->base() == loc && c->vsnode() == this &&
            c->is_free(), "Sanity");
-    DEBUG_ONLY(c->verify();)
+    SOMETIMES(c->verify();)
 
     UL2(debug, "new root chunk " METACHUNK_FORMAT ".", METACHUNK_FORMAT_ARGS(c));
     return c;
@@ -338,7 +338,7 @@ void VirtualSpaceNode::split(chunklevel_t target_level, Metachunk* c, FreeChunkL
   assert_lock_strong(Metaspace_lock);
   // Get the area associated with this chunk and let it handle the splitting
   RootChunkArea* rca = _root_chunk_area_lut.get_area_by_address(c->base());
-  DEBUG_ONLY(rca->verify_area_is_ideally_merged();)
+  SOMETIMES(rca->verify_area_is_ideally_merged();)
   rca->split(target_level, c, freelists);
 }
 
@@ -358,7 +358,7 @@ Metachunk* VirtualSpaceNode::merge(Metachunk* c, FreeChunkListVector* freelists)
   // Get the rca associated with this chunk and let it handle the merging
   RootChunkArea* rca = _root_chunk_area_lut.get_area_by_address(c->base());
   Metachunk* c2 = rca->merge(c, freelists);
-  DEBUG_ONLY(rca->verify_area_is_ideally_merged();)
+  SOMETIMES(rca->verify_area_is_ideally_merged();)
   return c2;
 }
 
@@ -379,7 +379,7 @@ bool VirtualSpaceNode::attempt_enlarge_chunk(Metachunk* c, FreeChunkListVector*
   RootChunkArea* rca = _root_chunk_area_lut.get_area_by_address(c->base());
 
   bool rc = rca->attempt_enlarge_chunk(c, freelists);
-  DEBUG_ONLY(rca->verify_area_is_ideally_merged();)
+  SOMETIMES(rca->verify_area_is_ideally_merged();)
   if (rc) {
     InternalStats::inc_num_chunks_enlarged();
   }

test/hotspot/jtreg/gtest/MetaspaceGtests.java

@@ -37,7 +37,7 @@
  *          java.xml
  * @requires vm.debug
  * @requires vm.flagless
- * @run main/native GTestWrapper --gtest_filter=metaspace* -XX:+UnlockDiagnosticVMOptions -XX:VerifyMetaspaceInterval=3
+ * @run main/native GTestWrapper --gtest_filter=metaspace* -XX:+UnlockDiagnosticVMOptions -XX:VerifyMetaspaceInterval=1
  */
 
 /* @test id=balanced-with-guards
@@ -47,7 +47,7 @@
  *          java.xml
  * @requires vm.debug
  * @requires vm.flagless
- * @run main/native GTestWrapper --gtest_filter=metaspace* -XX:VerifyMetaspaceInterval=3 -XX:+MetaspaceGuardAllocations
+ * @run main/native GTestWrapper --gtest_filter=metaspace* -XX:VerifyMetaspaceInterval=1 -XX:+MetaspaceGuardAllocations
  */
 
 /* @test id=balanced-no-ccs