jdk8-mips64-public/hotspot: src/share/vm/gc_implementation/g1/g1CodeCacheRemSet.cpp@7baf47cb97cb (annotated)

src/share/vm/gc_implementation/g1/g1CodeCacheRemSet.cpp@7baf47cb97cb (annotated)

src/share/vm/gc_implementation/g1/g1CodeCacheRemSet.cpp

Fri, 29 Aug 2014 13:12:21 +0200

author: mgerdin
date: Fri, 29 Aug 2014 13:12:21 +0200
changeset 7208: 7baf47cb97cb
parent 6993: 870c03421152
child 7209: 58925d1f325e
permissions: -rw-r--r--

8048268: G1 Code Root Migration performs poorly
Summary: Replace G1CodeRootSet with a Hashtable based implementation, merge Code Root Migration phase into Code Root Scanning
Reviewed-by: jmasa, brutisso, tschatzl

 /*
  * Copyright (c) 2014, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
  * under the terms of the GNU General Public License version 2 only, as
  * published by the Free Software Foundation.
  *
  * This code is distributed in the hope that it will be useful, but WITHOUT
  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  * version 2 for more details (a copy is included in the LICENSE file that
  * accompanied this code).
  *
  * You should have received a copy of the GNU General Public License version
  * 2 along with this work; if not, write to the Free Software Foundation,
  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  *
  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  * or visit www.oracle.com if you need additional information or have any
  * questions.
  *
  */
 #include "precompiled.hpp"
 #include "code/codeCache.hpp"
 #include "code/nmethod.hpp"
 #include "gc_implementation/g1/g1CodeCacheRemSet.hpp"
 #include "gc_implementation/g1/heapRegion.hpp"
 #include "memory/heap.hpp"
 #include "memory/iterator.hpp"
 #include "oops/oop.inline.hpp"
 #include "utilities/hashtable.inline.hpp"
 #include "utilities/stack.inline.hpp"
 PRAGMA_FORMAT_MUTE_WARNINGS_FOR_GCC
 class CodeRootSetTable : public Hashtable<nmethod*, mtGC> {
   friend class G1CodeRootSetTest;
   typedef HashtableEntry<nmethod*, mtGC> Entry;
   static CodeRootSetTable* volatile _purge_list;
   CodeRootSetTable* _purge_next;
   unsigned int compute_hash(nmethod* nm) {
     uintptr_t hash = (uintptr_t)nm;
     return hash ^ (hash >> 7); // code heap blocks are 128byte aligned
   }
   Entry* new_entry(nmethod* nm);
  public:
   CodeRootSetTable(int size) : Hashtable<nmethod*, mtGC>(size, sizeof(Entry)), _purge_next(NULL) {}
   ~CodeRootSetTable();
   // Needs to be protected locks
   bool add(nmethod* nm);
   bool remove(nmethod* nm);
   // Can be called without locking
   bool contains(nmethod* nm);
   int entry_size() const { return BasicHashtable<mtGC>::entry_size(); }
   void copy_to(CodeRootSetTable* new_table);
   void nmethods_do(CodeBlobClosure* blk);
   template<typename CB>
   void remove_if(CB& should_remove);
   static void purge_list_append(CodeRootSetTable* tbl);
   static void purge();
   static size_t static_mem_size() {
     return sizeof(_purge_list);
   }
 };
 CodeRootSetTable* volatile CodeRootSetTable::_purge_list = NULL;
 CodeRootSetTable::Entry* CodeRootSetTable::new_entry(nmethod* nm) {
   unsigned int hash = compute_hash(nm);
   Entry* entry = (Entry*) new_entry_free_list();
   if (entry == NULL) {
     entry = (Entry*) NEW_C_HEAP_ARRAY2(char, entry_size(), mtGC, CURRENT_PC);
   }
   entry->set_next(NULL);
   entry->set_hash(hash);
   entry->set_literal(nm);
   return entry;
 }
 CodeRootSetTable::~CodeRootSetTable() {
   for (int index = 0; index < table_size(); ++index) {
     for (Entry* e = bucket(index); e != NULL; ) {
       Entry* to_remove = e;
       // read next before freeing.
       e = e->next();
       unlink_entry(to_remove);
       FREE_C_HEAP_ARRAY(char, to_remove, mtGC);
     }
   }
   assert(number_of_entries() == 0, "should have removed all entries");
   free_buckets();
   for (BasicHashtableEntry<mtGC>* e = new_entry_free_list(); e != NULL; e = new_entry_free_list()) {
     FREE_C_HEAP_ARRAY(char, e, mtGC);
   }
 }
 bool CodeRootSetTable::add(nmethod* nm) {
   if (!contains(nm)) {
     Entry* e = new_entry(nm);
     int index = hash_to_index(e->hash());
     add_entry(index, e);
     return true;
   }
   return false;
 }
 bool CodeRootSetTable::contains(nmethod* nm) {
   int index = hash_to_index(compute_hash(nm));
   for (Entry* e = bucket(index); e != NULL; e = e->next()) {
     if (e->literal() == nm) {
       return true;
     }
   }
   return false;
 }
 bool CodeRootSetTable::remove(nmethod* nm) {
   int index = hash_to_index(compute_hash(nm));
   Entry* previous = NULL;
   for (Entry* e = bucket(index); e != NULL; previous = e, e = e->next()) {
     if (e->literal() == nm) {
       if (previous != NULL) {
         previous->set_next(e->next());
       } else {
         set_entry(index, e->next());
       }
       free_entry(e);
       return true;
     }
   }
   return false;
 }
 void CodeRootSetTable::copy_to(CodeRootSetTable* new_table) {
   for (int index = 0; index < table_size(); ++index) {
     for (Entry* e = bucket(index); e != NULL; e = e->next()) {
       new_table->add(e->literal());
     }
   }
   new_table->copy_freelist(this);
 }
 void CodeRootSetTable::nmethods_do(CodeBlobClosure* blk) {
   for (int index = 0; index < table_size(); ++index) {
     for (Entry* e = bucket(index); e != NULL; e = e->next()) {
       blk->do_code_blob(e->literal());
     }
   }
 }
 template<typename CB>
 void CodeRootSetTable::remove_if(CB& should_remove) {
   for (int index = 0; index < table_size(); ++index) {
     Entry* previous = NULL;
     Entry* e = bucket(index);
     while (e != NULL) {
       Entry* next = e->next();
       if (should_remove(e->literal())) {
         if (previous != NULL) {
           previous->set_next(next);
         } else {
           set_entry(index, next);
         }
         free_entry(e);
       } else {
         previous = e;
       }
       e = next;
     }
   }
 }
 G1CodeRootSet::~G1CodeRootSet() {
   delete _table;
 }
 CodeRootSetTable* G1CodeRootSet::load_acquire_table() {
   return (CodeRootSetTable*) OrderAccess::load_ptr_acquire(&_table);
 }
 void G1CodeRootSet::allocate_small_table() {
   _table = new CodeRootSetTable(SmallSize);
 }
 void CodeRootSetTable::purge_list_append(CodeRootSetTable* table) {
   for (;;) {
     table->_purge_next = _purge_list;
     CodeRootSetTable* old = (CodeRootSetTable*) Atomic::cmpxchg_ptr(table, &_purge_list, table->_purge_next);
     if (old == table->_purge_next) {
       break;
     }
   }
 }
 void CodeRootSetTable::purge() {
   CodeRootSetTable* table = _purge_list;
   _purge_list = NULL;
   while (table != NULL) {
     CodeRootSetTable* to_purge = table;
     table = table->_purge_next;
     delete to_purge;
   }
 }
 void G1CodeRootSet::move_to_large() {
   CodeRootSetTable* temp = new CodeRootSetTable(LargeSize);
   _table->copy_to(temp);
   CodeRootSetTable::purge_list_append(_table);
   OrderAccess::release_store_ptr(&_table, temp);
 }
 void G1CodeRootSet::purge() {
   CodeRootSetTable::purge();
 }
 size_t G1CodeRootSet::static_mem_size() {
   return CodeRootSetTable::static_mem_size();
 }
 void G1CodeRootSet::add(nmethod* method) {
   bool added = false;
   if (is_empty()) {
     allocate_small_table();
   }
   added = _table->add(method);
   if (_length == Threshold) {
     move_to_large();
   }
   if (added) {
     ++_length;
   }
 }
 bool G1CodeRootSet::remove(nmethod* method) {
   bool removed = false;
   if (_table != NULL) {
     removed = _table->remove(method);
   }
   if (removed) {
     _length--;
     if (_length == 0) {
       clear();
     }
   }
   return removed;
 }
 bool G1CodeRootSet::contains(nmethod* method) {
   CodeRootSetTable* table = load_acquire_table();
   if (table != NULL) {
     return table->contains(method);
   }
   return false;
 }
 void G1CodeRootSet::clear() {
   delete _table;
   _table = NULL;
   _length = 0;
 }
 size_t G1CodeRootSet::mem_size() {
   return sizeof(*this) +
       (_table != NULL ? sizeof(CodeRootSetTable) + _table->entry_size() * _length : 0);
 }
 void G1CodeRootSet::nmethods_do(CodeBlobClosure* blk) const {
   if (_table != NULL) {
     _table->nmethods_do(blk);
   }
 }
 class CleanCallback : public StackObj {
   class PointsIntoHRDetectionClosure : public OopClosure {
     HeapRegion* _hr;
    public:
     bool _points_into;
     PointsIntoHRDetectionClosure(HeapRegion* hr) : _hr(hr), _points_into(false) {}
     void do_oop(narrowOop* o) {
       do_oop_work(o);
     }
     void do_oop(oop* o) {
       do_oop_work(o);
     }
     template <typename T>
     void do_oop_work(T* p) {
       if (_hr->is_in(oopDesc::load_decode_heap_oop(p))) {
         _points_into = true;
       }
     }
   };
   PointsIntoHRDetectionClosure _detector;
   CodeBlobToOopClosure _blobs;
  public:
   CleanCallback(HeapRegion* hr) : _detector(hr), _blobs(&_detector, !CodeBlobToOopClosure::FixRelocations) {}
   bool operator() (nmethod* nm) {
     _detector._points_into = false;
     _blobs.do_code_blob(nm);
     return _detector._points_into;
   }
 };
 void G1CodeRootSet::clean(HeapRegion* owner) {
   CleanCallback should_clean(owner);
   if (_table != NULL) {
     _table->remove_if(should_clean);
   }
 }
 #ifndef PRODUCT
 class G1CodeRootSetTest {
  public:
   static void test() {
     {
       G1CodeRootSet set1;
       assert(set1.is_empty(), "Code root set must be initially empty but is not.");
       assert(G1CodeRootSet::static_mem_size() == sizeof(void*),
           err_msg("The code root set's static memory usage is incorrect, "SIZE_FORMAT" bytes", G1CodeRootSet::static_mem_size()));
       set1.add((nmethod*)1);
       assert(set1.length() == 1, err_msg("Added exactly one element, but set contains "
           SIZE_FORMAT" elements", set1.length()));
       const size_t num_to_add = (size_t)G1CodeRootSet::Threshold + 1;
       for (size_t i = 1; i <= num_to_add; i++) {
         set1.add((nmethod*)1);
       }
       assert(set1.length() == 1,
           err_msg("Duplicate detection should not have increased the set size but "
               "is "SIZE_FORMAT, set1.length()));
       for (size_t i = 2; i <= num_to_add; i++) {
         set1.add((nmethod*)(uintptr_t)(i));
       }
       assert(set1.length() == num_to_add,
           err_msg("After adding in total "SIZE_FORMAT" distinct code roots, they "
               "need to be in the set, but there are only "SIZE_FORMAT,
               num_to_add, set1.length()));
       assert(CodeRootSetTable::_purge_list != NULL, "should have grown to large hashtable");
       size_t num_popped = 0;
       for (size_t i = 1; i <= num_to_add; i++) {
         bool removed = set1.remove((nmethod*)i);
         if (removed) {
           num_popped += 1;
         } else {
           break;
         }
       }
       assert(num_popped == num_to_add,
           err_msg("Managed to pop "SIZE_FORMAT" code roots, but only "SIZE_FORMAT" "
               "were added", num_popped, num_to_add));
       assert(CodeRootSetTable::_purge_list != NULL, "should have grown to large hashtable");
       G1CodeRootSet::purge();
       assert(CodeRootSetTable::_purge_list == NULL, "should have purged old small tables");
     }
   }
 };
 void TestCodeCacheRemSet_test() {
   G1CodeRootSetTest::test();
 }
 #endif

Mercurial > jdk8-mips64-public > hotspot / annotate

src/share/vm/gc_implementation/g1/g1CodeCacheRemSet.cpp@7baf47cb97cb (annotated)

src/share/vm/gc_implementation/g1/g1CodeCacheRemSet.cpp