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8048268: G1 Code Root Migration performs poorly

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Replace G1CodeRootSet with a Hashtable based implementation, merge Code Root Migration phase into Code Root Scanning

Reviewed-by: jmasa, brutisso, tschatzl
This commit is contained in:
Mikael Gerdin 2014-08-29 13:12:21 +02:00
parent 6fc8764c65
commit 10379e7e82
17 changed files with 437 additions and 677 deletions
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617
hotspot/src/share/vm/gc_implementation/g1/g1CodeCacheRemSet.cpp
View File

@ -22,372 +22,375 @@
*
*/
#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
G1CodeRootChunk::G1CodeRootChunk() : _top(NULL), _next(NULL), _prev(NULL), _free(NULL) {
_top = bottom();
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;
}
void G1CodeRootChunk::reset() {
_next = _prev = NULL;
_free = NULL;
_top = bottom();
}
void G1CodeRootChunk::nmethods_do(CodeBlobClosure* cl) {
NmethodOrLink* cur = bottom();
while (cur != _top) {
if (is_nmethod(cur)) {
cl->do_code_blob(cur->_nmethod);
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);
}
cur++;
}
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 G1CodeRootChunk::remove_lock_free(nmethod* method) {
NmethodOrLink* cur = bottom();
for (NmethodOrLink* cur = bottom(); cur != _top; cur++) {
if (cur->_nmethod == method) {
bool result = Atomic::cmpxchg_ptr(NULL, &cur->_nmethod, method) == method;
if (!result) {
// Someone else cleared out this entry.
return false;
}
// The method was cleared. Time to link it into the free list.
NmethodOrLink* prev_free;
do {
prev_free = (NmethodOrLink*)_free;
cur->_link = prev_free;
} while (Atomic::cmpxchg_ptr(cur, &_free, prev_free) != prev_free);
return true;
}
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;
}
G1CodeRootChunkManager::G1CodeRootChunkManager() : _free_list(), _num_chunks_handed_out(0) {
_free_list.initialize();
_free_list.set_size(G1CodeRootChunk::word_size());
}
size_t G1CodeRootChunkManager::fl_mem_size() {
return _free_list.count() * _free_list.size();
}
void G1CodeRootChunkManager::free_all_chunks(FreeList<G1CodeRootChunk>* list) {
_num_chunks_handed_out -= list->count();
_free_list.prepend(list);
}
void G1CodeRootChunkManager::free_chunk(G1CodeRootChunk* chunk) {
_free_list.return_chunk_at_head(chunk);
_num_chunks_handed_out--;
}
void G1CodeRootChunkManager::purge_chunks(size_t keep_ratio) {
size_t keep = _num_chunks_handed_out * keep_ratio / 100;
if (keep >= (size_t)_free_list.count()) {
return;
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;
}
FreeList<G1CodeRootChunk> temp;
temp.initialize();
temp.set_size(G1CodeRootChunk::word_size());
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;
}
_free_list.getFirstNChunksFromList((size_t)_free_list.count() - keep, &temp);
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);
}
G1CodeRootChunk* cur = temp.get_chunk_at_head();
while (cur != NULL) {
delete cur;
cur = temp.get_chunk_at_head();
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());
}
}
}
size_t G1CodeRootChunkManager::static_mem_size() {
return sizeof(G1CodeRootChunkManager);
}
G1CodeRootChunk* G1CodeRootChunkManager::new_chunk() {
G1CodeRootChunk* result = _free_list.get_chunk_at_head();
if (result == NULL) {
result = new G1CodeRootChunk();
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;
}
}
_num_chunks_handed_out++;
result->reset();
return result;
}
#ifndef PRODUCT
size_t G1CodeRootChunkManager::num_chunks_handed_out() const {
return _num_chunks_handed_out;
}
size_t G1CodeRootChunkManager::num_free_chunks() const {
return (size_t)_free_list.count();
}
#endif
G1CodeRootChunkManager G1CodeRootSet::_default_chunk_manager;
void G1CodeRootSet::purge_chunks(size_t keep_ratio) {
_default_chunk_manager.purge_chunks(keep_ratio);
}
size_t G1CodeRootSet::free_chunks_static_mem_size() {
return _default_chunk_manager.static_mem_size();
}
size_t G1CodeRootSet::free_chunks_mem_size() {
return _default_chunk_manager.fl_mem_size();
}
G1CodeRootSet::G1CodeRootSet(G1CodeRootChunkManager* manager) : _manager(manager), _list(), _length(0) {
if (_manager == NULL) {
_manager = &_default_chunk_manager;
}
_list.initialize();
_list.set_size(G1CodeRootChunk::word_size());
}
G1CodeRootSet::~G1CodeRootSet() {
clear();
delete _table;
}
void G1CodeRootSet::add(nmethod* method) {
if (!contains(method)) {
// Find the first chunk that isn't full.
G1CodeRootChunk* cur = _list.head();
while (cur != NULL) {
if (!cur->is_full()) {
break;
}
cur = cur->next();
}
// All chunks are full, get a new chunk.
if (cur == NULL) {
cur = new_chunk();
_list.return_chunk_at_head(cur);
}
// Add the nmethod.
bool result = cur->add(method);
guarantee(result, err_msg("Not able to add nmethod "PTR_FORMAT" to newly allocated chunk.", method));
_length++;
}
CodeRootSetTable* G1CodeRootSet::load_acquire_table() {
return (CodeRootSetTable*) OrderAccess::load_ptr_acquire(&_table);
}
void G1CodeRootSet::remove_lock_free(nmethod* method) {
G1CodeRootChunk* found = find(method);
if (found != NULL) {
bool result = found->remove_lock_free(method);
if (result) {
Atomic::dec_ptr((volatile intptr_t*)&_length);
}
}
assert(!contains(method), err_msg(PTR_FORMAT" still contains nmethod "PTR_FORMAT, this, method));
void G1CodeRootSet::allocate_small_table() {
_table = new CodeRootSetTable(SmallSize);
}
nmethod* G1CodeRootSet::pop() {
while (true) {
G1CodeRootChunk* cur = _list.head();
if (cur == NULL) {
assert(_length == 0, "when there are no chunks, there should be no elements");
return NULL;
}
nmethod* result = cur->pop();
if (result != NULL) {
_length--;
return result;
} else {
free(_list.get_chunk_at_head());
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;
}
}
}
G1CodeRootChunk* G1CodeRootSet::find(nmethod* method) {
G1CodeRootChunk* cur = _list.head();
while (cur != NULL) {
if (cur->contains(method)) {
return cur;
}
cur = (G1CodeRootChunk*)cur->next();
void CodeRootSetTable::purge() {
CodeRootSetTable* table = _purge_list;
_purge_list = NULL;
while (table != NULL) {
CodeRootSetTable* to_purge = table;
table = table->_purge_next;
delete to_purge;
}
return NULL;
}
void G1CodeRootSet::free(G1CodeRootChunk* chunk) {
free_chunk(chunk);
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);
}
bool G1CodeRootSet::contains(nmethod* method) {
return find(method) != NULL;
}
void G1CodeRootSet::clear() {
free_all_chunks(&_list);
_length = 0;
}
void G1CodeRootSet::nmethods_do(CodeBlobClosure* blk) const {
G1CodeRootChunk* cur = _list.head();
while (cur != NULL) {
cur->nmethods_do(blk);
cur = (G1CodeRootChunk*)cur->next();
}
void G1CodeRootSet::purge() {
CodeRootSetTable::purge();
}
size_t G1CodeRootSet::static_mem_size() {
return sizeof(G1CodeRootSet);
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 G1CodeRootSet::static_mem_size() + _list.count() * _list.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
void G1CodeRootSet::test() {
G1CodeRootChunkManager mgr;
assert(mgr.num_chunks_handed_out() == 0, "Must not have handed out chunks yet");
assert(G1CodeRootChunkManager::static_mem_size() > sizeof(void*),
err_msg("The chunk manager's static memory usage seems too small, is only "SIZE_FORMAT" bytes.", G1CodeRootChunkManager::static_mem_size()));
// The number of chunks that we allocate for purge testing.
size_t const num_chunks = 10;
{
G1CodeRootSet set1(&mgr);
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 seems too small, is only "SIZE_FORMAT" bytes", G1CodeRootSet::static_mem_size()));
set1.add((nmethod*)1);
assert(mgr.num_chunks_handed_out() == 1,
err_msg("Must have allocated and handed out one chunk, but handed out "
SIZE_FORMAT" chunks", mgr.num_chunks_handed_out()));
assert(set1.length() == 1, err_msg("Added exactly one element, but set contains "
SIZE_FORMAT" elements", set1.length()));
// G1CodeRootChunk::word_size() is larger than G1CodeRootChunk::num_entries which
// we cannot access.
for (uint i = 0; i < G1CodeRootChunk::word_size() + 1; i++) {
set1.add((nmethod*)1);
}
assert(mgr.num_chunks_handed_out() == 1,
err_msg("Duplicate detection must have prevented allocation of further "
"chunks but allocated "SIZE_FORMAT, mgr.num_chunks_handed_out()));
assert(set1.length() == 1,
err_msg("Duplicate detection should not have increased the set size but "
"is "SIZE_FORMAT, set1.length()));
size_t num_total_after_add = G1CodeRootChunk::word_size() + 1;
for (size_t i = 0; i < num_total_after_add - 1; i++) {
set1.add((nmethod*)(uintptr_t)(2 + i));
}
assert(mgr.num_chunks_handed_out() > 1,
"After adding more code roots, more than one additional chunk should have been handed out");
assert(set1.length() == num_total_after_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_total_after_add, set1.length()));
size_t num_popped = 0;
while (set1.pop() != NULL) {
num_popped++;
}
assert(num_popped == num_total_after_add,
err_msg("Managed to pop "SIZE_FORMAT" code roots, but only "SIZE_FORMAT" "
"were added", num_popped, num_total_after_add));
assert(mgr.num_chunks_handed_out() == 0,
err_msg("After popping all elements, all chunks must have been returned "
"but there are still "SIZE_FORMAT" additional", mgr.num_chunks_handed_out()));
mgr.purge_chunks(0);
assert(mgr.num_free_chunks() == 0,
err_msg("After purging everything, the free list must be empty but still "
"contains "SIZE_FORMAT" chunks", mgr.num_free_chunks()));
// Add some more handed out chunks.
size_t i = 0;
while (mgr.num_chunks_handed_out() < num_chunks) {
set1.add((nmethod*)i);
i++;
}
class G1CodeRootSetTest {
public:
static void test() {
{
// Generate chunks on the free list.
G1CodeRootSet set2(&mgr);
size_t i = 0;
while (mgr.num_chunks_handed_out() < (num_chunks * 2)) {
set2.add((nmethod*)i);
i++;
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);
}
// Exit of the scope of the set2 object will call the destructor that generates
// num_chunks elements on the free list.
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");
}
assert(mgr.num_chunks_handed_out() == num_chunks,
err_msg("Deletion of the second set must have resulted in giving back "
"those, but there are still "SIZE_FORMAT" additional handed out, expecting "
SIZE_FORMAT, mgr.num_chunks_handed_out(), num_chunks));
assert(mgr.num_free_chunks() == num_chunks,
err_msg("After freeing "SIZE_FORMAT" chunks, they must be on the free list "
"but there are only "SIZE_FORMAT, num_chunks, mgr.num_free_chunks()));
size_t const test_percentage = 50;
mgr.purge_chunks(test_percentage);
assert(mgr.num_chunks_handed_out() == num_chunks,
err_msg("Purging must not hand out chunks but there are "SIZE_FORMAT,
mgr.num_chunks_handed_out()));
assert(mgr.num_free_chunks() == (size_t)(mgr.num_chunks_handed_out() * test_percentage / 100),
err_msg("Must have purged "SIZE_FORMAT" percent of "SIZE_FORMAT" chunks"
"but there are "SIZE_FORMAT, test_percentage, num_chunks,
mgr.num_free_chunks()));
// Purge the remainder of the chunks on the free list.
mgr.purge_chunks(0);
assert(mgr.num_free_chunks() == 0, "Free List must be empty");
assert(mgr.num_chunks_handed_out() == num_chunks,
err_msg("Expected to be "SIZE_FORMAT" chunks handed out from the first set "
"but there are "SIZE_FORMAT, num_chunks, mgr.num_chunks_handed_out()));
// Exit of the scope of the set1 object will call the destructor that generates
// num_chunks additional elements on the free list.
}
assert(mgr.num_chunks_handed_out() == 0,
err_msg("Deletion of the only set must have resulted in no chunks handed "
"out, but there is still "SIZE_FORMAT" handed out", mgr.num_chunks_handed_out()));
assert(mgr.num_free_chunks() == num_chunks,
err_msg("After freeing "SIZE_FORMAT" chunks, they must be on the free list "
"but there are only "SIZE_FORMAT, num_chunks, mgr.num_free_chunks()));
// Restore initial state.
mgr.purge_chunks(0);
assert(mgr.num_free_chunks() == 0, "Free List must be empty");
assert(mgr.num_chunks_handed_out() == 0, "No additional elements must have been handed out yet");
}
}
};
void TestCodeCacheRemSet_test() {
G1CodeRootSet::test();
G1CodeRootSetTest::test();
}
#endif

208
hotspot/src/share/vm/gc_implementation/g1/g1CodeCacheRemSet.hpp
View File

@ -26,222 +26,64 @@
#define SHARE_VM_GC_IMPLEMENTATION_G1_G1CODECACHEREMSET_HPP
#include "memory/allocation.hpp"
#include "memory/freeList.hpp"
#include "runtime/globals.hpp"
class CodeBlobClosure;
// The elements of the G1CodeRootChunk is either:
// 1) nmethod pointers
// 2) nodes in an internally chained free list
typedef union {
nmethod* _nmethod;
void* _link;
} NmethodOrLink;
class G1CodeRootChunk : public CHeapObj<mtGC> {
private:
static const int NUM_ENTRIES = 32;
public:
G1CodeRootChunk* _next;
G1CodeRootChunk* _prev;
NmethodOrLink* _top;
// First free position within the chunk.
volatile NmethodOrLink* _free;
NmethodOrLink _data[NUM_ENTRIES];
NmethodOrLink* bottom() const {
return (NmethodOrLink*) &(_data[0]);
}
NmethodOrLink* end() const {
return (NmethodOrLink*) &(_data[NUM_ENTRIES]);
}
bool is_link(NmethodOrLink* nmethod_or_link) {
return nmethod_or_link->_link == NULL ||
(bottom() <= nmethod_or_link->_link
&& nmethod_or_link->_link < end());
}
bool is_nmethod(NmethodOrLink* nmethod_or_link) {
return !is_link(nmethod_or_link);
}
public:
G1CodeRootChunk();
~G1CodeRootChunk() {}
static size_t word_size() { return (size_t)(align_size_up_(sizeof(G1CodeRootChunk), HeapWordSize) / HeapWordSize); }
// FreeList "interface" methods
G1CodeRootChunk* next() const { return _next; }
G1CodeRootChunk* prev() const { return _prev; }
void set_next(G1CodeRootChunk* v) { _next = v; assert(v != this, "Boom");}
void set_prev(G1CodeRootChunk* v) { _prev = v; assert(v != this, "Boom");}
void clear_next() { set_next(NULL); }
void clear_prev() { set_prev(NULL); }
size_t size() const { return word_size(); }
void link_next(G1CodeRootChunk* ptr) { set_next(ptr); }
void link_prev(G1CodeRootChunk* ptr) { set_prev(ptr); }
void link_after(G1CodeRootChunk* ptr) {
link_next(ptr);
if (ptr != NULL) ptr->link_prev((G1CodeRootChunk*)this);
}
bool is_free() { return true; }
// New G1CodeRootChunk routines
void reset();
bool is_empty() const {
return _top == bottom();
}
bool is_full() const {
return _top == end() && _free == NULL;
}
bool contains(nmethod* method) {
NmethodOrLink* cur = bottom();
while (cur != _top) {
if (cur->_nmethod == method) return true;
cur++;
}
return false;
}
bool add(nmethod* method) {
if (is_full()) {
return false;
}
if (_free != NULL) {
// Take from internally chained free list
NmethodOrLink* first_free = (NmethodOrLink*)_free;
_free = (NmethodOrLink*)_free->_link;
first_free->_nmethod = method;
} else {
// Take from top.
_top->_nmethod = method;
_top++;
}
return true;
}
bool remove_lock_free(nmethod* method);
void nmethods_do(CodeBlobClosure* blk);
nmethod* pop() {
if (_free != NULL) {
// Kill the free list.
_free = NULL;
}
while (!is_empty()) {
_top--;
if (is_nmethod(_top)) {
return _top->_nmethod;
}
}
return NULL;
}
};
// Manages free chunks.
class G1CodeRootChunkManager VALUE_OBJ_CLASS_SPEC {
private:
// Global free chunk list management
FreeList<G1CodeRootChunk> _free_list;
// Total number of chunks handed out
size_t _num_chunks_handed_out;
public:
G1CodeRootChunkManager();
G1CodeRootChunk* new_chunk();
void free_chunk(G1CodeRootChunk* chunk);
// Free all elements of the given list.
void free_all_chunks(FreeList<G1CodeRootChunk>* list);
void initialize();
void purge_chunks(size_t keep_ratio);
static size_t static_mem_size();
size_t fl_mem_size();
#ifndef PRODUCT
size_t num_chunks_handed_out() const;
size_t num_free_chunks() const;
#endif
};
class CodeRootSetTable;
class HeapRegion;
class nmethod;
// Implements storage for a set of code roots.
// All methods that modify the set are not thread-safe except if otherwise noted.
class G1CodeRootSet VALUE_OBJ_CLASS_SPEC {
friend class G1CodeRootSetTest;
private:
// Global default free chunk manager instance.
static G1CodeRootChunkManager _default_chunk_manager;
G1CodeRootChunk* new_chunk() { return _manager->new_chunk(); }
void free_chunk(G1CodeRootChunk* chunk) { _manager->free_chunk(chunk); }
// Free all elements of the given list.
void free_all_chunks(FreeList<G1CodeRootChunk>* list) { _manager->free_all_chunks(list); }
const static size_t SmallSize = 32;
const static size_t Threshold = 24;
const static size_t LargeSize = 512;
// Return the chunk that contains the given nmethod, NULL otherwise.
// Scans the list of chunks backwards, as this method is used to add new
// entries, which are typically added in bulk for a single nmethod.
G1CodeRootChunk* find(nmethod* method);
void free(G1CodeRootChunk* chunk);
CodeRootSetTable* _table;
CodeRootSetTable* load_acquire_table();
size_t _length;
FreeList<G1CodeRootChunk> _list;
G1CodeRootChunkManager* _manager;
void move_to_large();
void allocate_small_table();
public:
// If an instance is initialized with a chunk manager of NULL, use the global
// default one.
G1CodeRootSet(G1CodeRootChunkManager* manager = NULL);
G1CodeRootSet() : _table(NULL), _length(0) {}
~G1CodeRootSet();
static void purge_chunks(size_t keep_ratio);
static void purge();
static size_t free_chunks_static_mem_size();
static size_t free_chunks_mem_size();
static size_t static_mem_size();
// Search for the code blob from the recently allocated ones to find duplicates more quickly, as this
// method is likely to be repeatedly called with the same nmethod.
void add(nmethod* method);
void remove_lock_free(nmethod* method);
nmethod* pop();
bool remove(nmethod* method);
// Safe to call without synchronization, but may return false negatives.
bool contains(nmethod* method);
void clear();
void nmethods_do(CodeBlobClosure* blk) const;
bool is_empty() { return length() == 0; }
// Remove all nmethods which no longer contain pointers into our "owner" region
void clean(HeapRegion* owner);
bool is_empty() {
bool empty = length() == 0;
assert(empty == (_table == NULL), "is empty only if table is deallocated");
return empty;
}
// Length in elements
size_t length() const { return _length; }
// Static data memory size in bytes of this set.
static size_t static_mem_size();
// Memory size in bytes taken by this set.
size_t mem_size();
static void test() PRODUCT_RETURN;
};
#endif // SHARE_VM_GC_IMPLEMENTATION_G1_G1CODECACHEREMSET_HPP

107
hotspot/src/share/vm/gc_implementation/g1/g1CollectedHeap.cpp
View File

@ -4670,6 +4670,56 @@ class G1KlassScanClosure : public KlassClosure {
}
};
class G1CodeBlobClosure : public CodeBlobClosure {
class HeapRegionGatheringOopClosure : public OopClosure {
G1CollectedHeap* _g1h;
OopClosure* _work;
nmethod* _nm;
template <typename T>
void do_oop_work(T* p) {
_work->do_oop(p);
T oop_or_narrowoop = oopDesc::load_heap_oop(p);
if (!oopDesc::is_null(oop_or_narrowoop)) {
oop o = oopDesc::decode_heap_oop_not_null(oop_or_narrowoop);
HeapRegion* hr = _g1h->heap_region_containing_raw(o);
assert(!_g1h->obj_in_cs(o) || hr->rem_set()->strong_code_roots_list_contains(_nm), "if o still in CS then evacuation failed and nm must already be in the remset");
hr->add_strong_code_root(_nm);
}
}
public:
HeapRegionGatheringOopClosure(OopClosure* oc) : _g1h(G1CollectedHeap::heap()), _work(oc), _nm(NULL) {}
void do_oop(oop* o) {
do_oop_work(o);
}
void do_oop(narrowOop* o) {
do_oop_work(o);
}
void set_nm(nmethod* nm) {
_nm = nm;
}
};
HeapRegionGatheringOopClosure _oc;
public:
G1CodeBlobClosure(OopClosure* oc) : _oc(oc) {}
void do_code_blob(CodeBlob* cb) {
nmethod* nm = cb->as_nmethod_or_null();
if (nm != NULL) {
if (!nm->test_set_oops_do_mark()) {
_oc.set_nm(nm);
nm->oops_do(&_oc);
nm->fix_oop_relocations();
}
}
}
};
class G1ParTask : public AbstractGangTask {
protected:
G1CollectedHeap* _g1h;
@ -4738,22 +4788,6 @@ public:
}
};
class G1CodeBlobClosure: public CodeBlobClosure {
OopClosure* _f;
public:
G1CodeBlobClosure(OopClosure* f) : _f(f) {}
void do_code_blob(CodeBlob* blob) {
nmethod* that = blob->as_nmethod_or_null();
if (that != NULL) {
if (!that->test_set_oops_do_mark()) {
that->oops_do(_f);
that->fix_oop_relocations();
}
}
}
};
void work(uint worker_id) {
if (worker_id >= _n_workers) return; // no work needed this round
@ -4944,7 +4978,7 @@ g1_process_roots(OopClosure* scan_non_heap_roots,
g1_policy()->phase_times()->record_satb_filtering_time(worker_i, satb_filtering_ms);
// Now scan the complement of the collection set.
MarkingCodeBlobClosure scavenge_cs_nmethods(scan_non_heap_weak_roots, CodeBlobToOopClosure::FixRelocations);
G1CodeBlobClosure scavenge_cs_nmethods(scan_non_heap_weak_roots);
g1_rem_set()->oops_into_collection_set_do(scan_rs, &scavenge_cs_nmethods, worker_i);
@ -5991,12 +6025,6 @@ void G1CollectedHeap::evacuate_collection_set(EvacuationInfo& evacuation_info) {
hot_card_cache->reset_hot_cache();
hot_card_cache->set_use_cache(true);
// Migrate the strong code roots attached to each region in
// the collection set. Ideally we would like to do this
// after we have finished the scanning/evacuation of the
// strong code roots for a particular heap region.
migrate_strong_code_roots();
purge_code_root_memory();
if (g1_policy()->during_initial_mark_pause()) {
@ -7049,13 +7077,8 @@ class RegisterNMethodOopClosure: public OopClosure {
" starting at "HR_FORMAT,
_nm, HR_FORMAT_PARAMS(hr), HR_FORMAT_PARAMS(hr->humongous_start_region())));
// HeapRegion::add_strong_code_root() avoids adding duplicate
// entries but having duplicates is OK since we "mark" nmethods
// as visited when we scan the strong code root lists during the GC.
hr->add_strong_code_root(_nm);
assert(hr->rem_set()->strong_code_roots_list_contains(_nm),
err_msg("failed to add code root "PTR_FORMAT" to remembered set of region "HR_FORMAT,
_nm, HR_FORMAT_PARAMS(hr)));
// HeapRegion::add_strong_code_root_locked() avoids adding duplicate entries.
hr->add_strong_code_root_locked(_nm);
}
}
@ -7082,9 +7105,6 @@ class UnregisterNMethodOopClosure: public OopClosure {
_nm, HR_FORMAT_PARAMS(hr), HR_FORMAT_PARAMS(hr->humongous_start_region())));
hr->remove_strong_code_root(_nm);
assert(!hr->rem_set()->strong_code_roots_list_contains(_nm),
err_msg("failed to remove code root "PTR_FORMAT" of region "HR_FORMAT,
_nm, HR_FORMAT_PARAMS(hr)));
}
}
@ -7112,28 +7132,9 @@ void G1CollectedHeap::unregister_nmethod(nmethod* nm) {
nm->oops_do(&reg_cl, true);
}
class MigrateCodeRootsHeapRegionClosure: public HeapRegionClosure {
public:
bool doHeapRegion(HeapRegion *hr) {
assert(!hr->isHumongous(),
err_msg("humongous region "HR_FORMAT" should not have been added to collection set",
HR_FORMAT_PARAMS(hr)));
hr->migrate_strong_code_roots();
return false;
}
};
void G1CollectedHeap::migrate_strong_code_roots() {
MigrateCodeRootsHeapRegionClosure cl;
double migrate_start = os::elapsedTime();
collection_set_iterate(&cl);
double migration_time_ms = (os::elapsedTime() - migrate_start) * 1000.0;
g1_policy()->phase_times()->record_strong_code_root_migration_time(migration_time_ms);
}
void G1CollectedHeap::purge_code_root_memory() {
double purge_start = os::elapsedTime();
G1CodeRootSet::purge_chunks(G1CodeRootsChunkCacheKeepPercent);
G1CodeRootSet::purge();
double purge_time_ms = (os::elapsedTime() - purge_start) * 1000.0;
g1_policy()->phase_times()->record_strong_code_root_purge_time(purge_time_ms);
}

6
hotspot/src/share/vm/gc_implementation/g1/g1CollectedHeap.hpp
View File

@ -1662,12 +1662,6 @@ public:
// Unregister the given nmethod from the G1 heap.
virtual void unregister_nmethod(nmethod* nm);
// Migrate the nmethods in the code root lists of the regions
// in the collection set to regions in to-space. In the event
// of an evacuation failure, nmethods that reference objects
// that were not successfully evacuated are not migrated.
void migrate_strong_code_roots();
// Free up superfluous code root memory.
void purge_code_root_memory();

2
hotspot/src/share/vm/gc_implementation/g1/g1EvacFailure.hpp
View File

@ -217,6 +217,8 @@ public:
_update_rset_cl->set_region(hr);
hr->object_iterate(&rspc);
hr->rem_set()->clean_strong_code_roots(hr);
hr->note_self_forwarding_removal_end(during_initial_mark,
during_conc_mark,
rspc.marked_bytes());

4
hotspot/src/share/vm/gc_implementation/g1/g1GCPhaseTimes.cpp
View File

@ -275,9 +275,6 @@ double G1GCPhaseTimes::accounted_time_ms() {
// Now subtract the time taken to fix up roots in generated code
misc_time_ms += _cur_collection_code_root_fixup_time_ms;
// Strong code root migration time
misc_time_ms += _cur_strong_code_root_migration_time_ms;
// Strong code root purge time
misc_time_ms += _cur_strong_code_root_purge_time_ms;
@ -328,7 +325,6 @@ void G1GCPhaseTimes::print(double pause_time_sec) {
_last_obj_copy_times_ms.print(1, "Object Copy (ms)");
}
print_stats(1, "Code Root Fixup", _cur_collection_code_root_fixup_time_ms);
print_stats(1, "Code Root Migration", _cur_strong_code_root_migration_time_ms);
print_stats(1, "Code Root Purge", _cur_strong_code_root_purge_time_ms);
if (G1StringDedup::is_enabled()) {
print_stats(1, "String Dedup Fixup", _cur_string_dedup_fixup_time_ms, _active_gc_threads);

5
hotspot/src/share/vm/gc_implementation/g1/g1GCPhaseTimes.hpp
View File

@ -129,7 +129,6 @@ class G1GCPhaseTimes : public CHeapObj<mtGC> {
double _cur_collection_par_time_ms;
double _cur_collection_code_root_fixup_time_ms;
double _cur_strong_code_root_migration_time_ms;
double _cur_strong_code_root_purge_time_ms;
double _cur_evac_fail_recalc_used;
@ -233,10 +232,6 @@ class G1GCPhaseTimes : public CHeapObj<mtGC> {
_cur_collection_code_root_fixup_time_ms = ms;
}
void record_strong_code_root_migration_time(double ms) {
_cur_strong_code_root_migration_time_ms = ms;
}
void record_strong_code_root_purge_time(double ms) {
_cur_strong_code_root_purge_time_ms = ms;
}

8
hotspot/src/share/vm/gc_implementation/g1/g1RemSet.cpp
View File

@ -110,7 +110,7 @@ class ScanRSClosure : public HeapRegionClosure {
G1CollectedHeap* _g1h;
OopsInHeapRegionClosure* _oc;
CodeBlobToOopClosure* _code_root_cl;
CodeBlobClosure* _code_root_cl;
G1BlockOffsetSharedArray* _bot_shared;
G1SATBCardTableModRefBS *_ct_bs;
@ -122,7 +122,7 @@ class ScanRSClosure : public HeapRegionClosure {
public:
ScanRSClosure(OopsInHeapRegionClosure* oc,
CodeBlobToOopClosure* code_root_cl,
CodeBlobClosure* code_root_cl,
uint worker_i) :
_oc(oc),
_code_root_cl(code_root_cl),
@ -242,7 +242,7 @@ public:
};
void G1RemSet::scanRS(OopsInHeapRegionClosure* oc,
CodeBlobToOopClosure* code_root_cl,
CodeBlobClosure* code_root_cl,
uint worker_i) {
double rs_time_start = os::elapsedTime();
HeapRegion *startRegion = _g1->start_cset_region_for_worker(worker_i);
@ -321,7 +321,7 @@ void G1RemSet::cleanupHRRS() {
}
void G1RemSet::oops_into_collection_set_do(OopsInHeapRegionClosure* oc,
CodeBlobToOopClosure* code_root_cl,
CodeBlobClosure* code_root_cl,
uint worker_i) {
#if CARD_REPEAT_HISTO
ct_freq_update_histo_and_reset();

4
hotspot/src/share/vm/gc_implementation/g1/g1RemSet.hpp
View File

@ -96,7 +96,7 @@ public:
// the "i" passed to the calling thread's work(i) function.
// In the sequential case this param will be ignored.
void oops_into_collection_set_do(OopsInHeapRegionClosure* blk,
CodeBlobToOopClosure* code_root_cl,
CodeBlobClosure* code_root_cl,
uint worker_i);
// Prepare for and cleanup after an oops_into_collection_set_do
@ -108,7 +108,7 @@ public:
void cleanup_after_oops_into_collection_set_do();
void scanRS(OopsInHeapRegionClosure* oc,
CodeBlobToOopClosure* code_root_cl,
CodeBlobClosure* code_root_cl,
uint worker_i);
void updateRS(DirtyCardQueue* into_cset_dcq, uint worker_i);

1
hotspot/src/share/vm/gc_implementation/g1/g1RemSetSummary.cpp
View File

@ -253,6 +253,7 @@ public:
size_t occupied_cards = hrrs->occupied();
size_t code_root_mem_sz = hrrs->strong_code_roots_mem_size();
if (code_root_mem_sz > max_code_root_mem_sz()) {
_max_code_root_mem_sz = code_root_mem_sz;
_max_code_root_mem_sz_region = r;
}
size_t code_root_elems = hrrs->strong_code_roots_list_length();

4
hotspot/src/share/vm/gc_implementation/g1/g1_globals.hpp
View File

@ -277,10 +277,6 @@
product(uintx, G1MixedGCCountTarget, 8, \
"The target number of mixed GCs after a marking cycle.") \
\
experimental(uintx, G1CodeRootsChunkCacheKeepPercent, 10, \
"The amount of code root chunks that should be kept at most " \
"as percentage of already allocated.") \
\
experimental(bool, G1ReclaimDeadHumongousObjectsAtYoungGC, true, \
"Try to reclaim dead large objects at every young GC.") \
\

16
hotspot/src/share/vm/gc_implementation/g1/heapRegion.cpp
View File

@ -540,21 +540,17 @@ void HeapRegion::add_strong_code_root(nmethod* nm) {
hrrs->add_strong_code_root(nm);
}
void HeapRegion::add_strong_code_root_locked(nmethod* nm) {
assert_locked_or_safepoint(CodeCache_lock);
HeapRegionRemSet* hrrs = rem_set();
hrrs->add_strong_code_root_locked(nm);
}
void HeapRegion::remove_strong_code_root(nmethod* nm) {
HeapRegionRemSet* hrrs = rem_set();
hrrs->remove_strong_code_root(nm);
}
void HeapRegion::migrate_strong_code_roots() {
assert(in_collection_set(), "only collection set regions");
assert(!isHumongous(),
err_msg("humongous region "HR_FORMAT" should not have been added to collection set",
HR_FORMAT_PARAMS(this)));
HeapRegionRemSet* hrrs = rem_set();
hrrs->migrate_strong_code_roots();
}
void HeapRegion::strong_code_roots_do(CodeBlobClosure* blk) const {
HeapRegionRemSet* hrrs = rem_set();
hrrs->strong_code_roots_do(blk);

7
hotspot/src/share/vm/gc_implementation/g1/heapRegion.hpp
View File

@ -756,14 +756,9 @@ class HeapRegion: public G1OffsetTableContigSpace {
// Routines for managing a list of code roots (attached to the
// this region's RSet) that point into this heap region.
void add_strong_code_root(nmethod* nm);
void add_strong_code_root_locked(nmethod* nm);
void remove_strong_code_root(nmethod* nm);
// During a collection, migrate the successfully evacuated
// strong code roots that referenced into this region to the
// new regions that they now point into. Unsuccessfully
// evacuated code roots are not migrated.
void migrate_strong_code_roots();
// Applies blk->do_code_blob() to each of the entries in
// the strong code roots list for this region
void strong_code_roots_do(CodeBlobClosure* blk) const;

105
hotspot/src/share/vm/gc_implementation/g1/heapRegionRemSet.cpp
View File

@ -926,8 +926,24 @@ void HeapRegionRemSet::scrub(CardTableModRefBS* ctbs,
}
// Code roots support
//
// The code root set is protected by two separate locking schemes
// When at safepoint the per-hrrs lock must be held during modifications
// except when doing a full gc.
// When not at safepoint the CodeCache_lock must be held during modifications.
// When concurrent readers access the contains() function
// (during the evacuation phase) no removals are allowed.
void HeapRegionRemSet::add_strong_code_root(nmethod* nm) {
assert(nm != NULL, "sanity");
// Optimistic unlocked contains-check
if (!_code_roots.contains(nm)) {
MutexLockerEx ml(&_m, Mutex::_no_safepoint_check_flag);
add_strong_code_root_locked(nm);
}
}
void HeapRegionRemSet::add_strong_code_root_locked(nmethod* nm) {
assert(nm != NULL, "sanity");
_code_roots.add(nm);
}
@ -936,98 +952,21 @@ void HeapRegionRemSet::remove_strong_code_root(nmethod* nm) {
assert(nm != NULL, "sanity");
assert_locked_or_safepoint(CodeCache_lock);
_code_roots.remove_lock_free(nm);
MutexLockerEx ml(CodeCache_lock->owned_by_self() ? NULL : &_m, Mutex::_no_safepoint_check_flag);
_code_roots.remove(nm);
// Check that there were no duplicates
guarantee(!_code_roots.contains(nm), "duplicate entry found");
}
class NMethodMigrationOopClosure : public OopClosure {
G1CollectedHeap* _g1h;
HeapRegion* _from;
nmethod* _nm;
uint _num_self_forwarded;
template <class T> void do_oop_work(T* p) {
T heap_oop = oopDesc::load_heap_oop(p);
if (!oopDesc::is_null(heap_oop)) {
oop obj = oopDesc::decode_heap_oop_not_null(heap_oop);
if (_from->is_in(obj)) {
// Reference still points into the source region.
// Since roots are immediately evacuated this means that
// we must have self forwarded the object
assert(obj->is_forwarded(),
err_msg("code roots should be immediately evacuated. "
"Ref: "PTR_FORMAT", "
"Obj: "PTR_FORMAT", "
"Region: "HR_FORMAT,
p, (void*) obj, HR_FORMAT_PARAMS(_from)));
assert(obj->forwardee() == obj,
err_msg("not self forwarded? obj = "PTR_FORMAT, (void*)obj));
// The object has been self forwarded.
// Note, if we're during an initial mark pause, there is
// no need to explicitly mark object. It will be marked
// during the regular evacuation failure handling code.
_num_self_forwarded++;
} else {
// The reference points into a promotion or to-space region
HeapRegion* to = _g1h->heap_region_containing(obj);
to->rem_set()->add_strong_code_root(_nm);
}
}
}
public:
NMethodMigrationOopClosure(G1CollectedHeap* g1h, HeapRegion* from, nmethod* nm):
_g1h(g1h), _from(from), _nm(nm), _num_self_forwarded(0) {}
void do_oop(narrowOop* p) { do_oop_work(p); }
void do_oop(oop* p) { do_oop_work(p); }
uint retain() { return _num_self_forwarded > 0; }
};
void HeapRegionRemSet::migrate_strong_code_roots() {
assert(hr()->in_collection_set(), "only collection set regions");
assert(!hr()->isHumongous(),
err_msg("humongous region "HR_FORMAT" should not have been added to the collection set",
HR_FORMAT_PARAMS(hr())));
ResourceMark rm;
// List of code blobs to retain for this region
GrowableArray<nmethod*> to_be_retained(10);
G1CollectedHeap* g1h = G1CollectedHeap::heap();
while (!_code_roots.is_empty()) {
nmethod *nm = _code_roots.pop();
if (nm != NULL) {
NMethodMigrationOopClosure oop_cl(g1h, hr(), nm);
nm->oops_do(&oop_cl);
if (oop_cl.retain()) {
to_be_retained.push(nm);
}
}
}
// Now push any code roots we need to retain
assert(to_be_retained.is_empty() || hr()->evacuation_failed(),
"Retained nmethod list must be empty or "
"evacuation of this region failed");
while (to_be_retained.is_nonempty()) {
nmethod* nm = to_be_retained.pop();
assert(nm != NULL, "sanity");
add_strong_code_root(nm);
}
}
void HeapRegionRemSet::strong_code_roots_do(CodeBlobClosure* blk) const {
_code_roots.nmethods_do(blk);
}
void HeapRegionRemSet::clean_strong_code_roots(HeapRegion* hr) {
_code_roots.clean(hr);
}
size_t HeapRegionRemSet::strong_code_roots_mem_size() {
return _code_roots.mem_size();
}

13
hotspot/src/share/vm/gc_implementation/g1/heapRegionRemSet.hpp
View File

@ -349,13 +349,13 @@ public:
// Returns the memory occupancy of all static data structures associated
// with remembered sets.
static size_t static_mem_size() {
return OtherRegionsTable::static_mem_size() + G1CodeRootSet::free_chunks_static_mem_size();
return OtherRegionsTable::static_mem_size() + G1CodeRootSet::static_mem_size();
}
// Returns the memory occupancy of all free_list data structures associated
// with remembered sets.
static size_t fl_mem_size() {
return OtherRegionsTable::fl_mem_size() + G1CodeRootSet::free_chunks_mem_size();
return OtherRegionsTable::fl_mem_size();
}
bool contains_reference(OopOrNarrowOopStar from) const {
@ -365,18 +365,15 @@ public:
// Routines for managing the list of code roots that point into
// the heap region that owns this RSet.
void add_strong_code_root(nmethod* nm);
void add_strong_code_root_locked(nmethod* nm);
void remove_strong_code_root(nmethod* nm);
// During a collection, migrate the successfully evacuated strong
// code roots that referenced into the region that owns this RSet
// to the RSets of the new regions that they now point into.
// Unsuccessfully evacuated code roots are not migrated.
void migrate_strong_code_roots();
// Applies blk->do_code_blob() to each of the entries in
// the strong code roots list
void strong_code_roots_do(CodeBlobClosure* blk) const;
void clean_strong_code_roots(HeapRegion* hr);
// Returns the number of elements in the strong code roots list
size_t strong_code_roots_list_length() const {
return _code_roots.length();

2
hotspot/src/share/vm/memory/freeList.cpp
View File

@ -34,7 +34,6 @@
#if INCLUDE_ALL_GCS
#include "gc_implementation/concurrentMarkSweep/freeChunk.hpp"
#include "gc_implementation/g1/g1CodeCacheRemSet.hpp"
#endif // INCLUDE_ALL_GCS
// Free list. A FreeList is used to access a linked list of chunks
@ -333,5 +332,4 @@ template class FreeList<Metablock>;
template class FreeList<Metachunk>;
#if INCLUDE_ALL_GCS
template class FreeList<FreeChunk>;
template class FreeList<G1CodeRootChunk>;
#endif // INCLUDE_ALL_GCS

5
hotspot/src/share/vm/utilities/hashtable.cpp
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@ -355,6 +355,11 @@ template <MEMFLAGS F> void BasicHashtable<F>::verify_lookup_length(double load)
// Explicitly instantiate these types
#if INCLUDE_ALL_GCS
template class Hashtable<nmethod*, mtGC>;
template class HashtableEntry<nmethod*, mtGC>;
template class BasicHashtable<mtGC>;
#endif
template class Hashtable<ConstantPool*, mtClass>;
template class RehashableHashtable<Symbol*, mtSymbol>;
template class RehashableHashtable<oopDesc*, mtSymbol>;