jdk8-mips64-public/hotspot: comparison src/share/vm/gc_implementation/g1/concurrentG1Refine.cpp

-:923ac8d1df95
+:194f52aa2f23
 /*
-* Copyright (c) 2001, 2012, Oracle and/or its affiliates. All rights reserved.
+* Copyright (c) 2001, 2013, 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.
 #include "precompiled.hpp"
 #include "gc_implementation/g1/concurrentG1Refine.hpp"
 #include "gc_implementation/g1/concurrentG1RefineThread.hpp"
 #include "gc_implementation/g1/g1CollectedHeap.inline.hpp"
-#include "gc_implementation/g1/g1CollectorPolicy.hpp"
+#include "gc_implementation/g1/g1HotCardCache.hpp"
-#include "gc_implementation/g1/g1GCPhaseTimes.hpp"
-#include "gc_implementation/g1/g1RemSet.hpp"
-#include "gc_implementation/g1/heapRegionSeq.inline.hpp"
-#include "memory/space.inline.hpp"
-#include "runtime/atomic.hpp"
-#include "runtime/java.hpp"
-#include "utilities/copy.hpp"
-// Possible sizes for the card counts cache: odd primes that roughly double in size.
+ConcurrentG1Refine::ConcurrentG1Refine(G1CollectedHeap* g1h) :
-// (See jvmtiTagMap.cpp).
+_threads(NULL), _n_threads(0),
+_hot_card_cache(g1h)
-#define MAX_SIZE ((size_t) -1)
-size_t ConcurrentG1Refine::_cc_cache_sizes[] = {
-16381,    32771,    76831,    150001,   307261,
-614563,  1228891,  2457733,   4915219,  9830479,
-19660831, 39321619, 78643219, 157286461,  MAX_SIZE
-};
-ConcurrentG1Refine::ConcurrentG1Refine() :
-_card_counts(NULL), _card_epochs(NULL),
-_n_card_counts(0), _max_cards(0), _max_n_card_counts(0),
-_cache_size_index(0), _expand_card_counts(false),
-_hot_cache(NULL),
-_def_use_cache(false), _use_cache(false),
-// We initialize the epochs of the array to 0. By initializing
-// _n_periods to 1 and not 0 we automatically invalidate all the
-// entries on the array. Otherwise we might accidentally think that
-// we claimed a card that was in fact never set (see CR7033292).
-_n_periods(1),
-_threads(NULL), _n_threads(0)
 {
 // Ergomonically select initial concurrent refinement parameters
 if (FLAG_IS_DEFAULT(G1ConcRefinementGreenZone)) {
 FLAG_SET_DEFAULT(G1ConcRefinementGreenZone, MAX2<int>(ParallelGCThreads, 1));
 }
 set_green_zone(G1ConcRefinementGreenZone);
 if (FLAG_IS_DEFAULT(G1ConcRefinementRedZone)) {
 FLAG_SET_DEFAULT(G1ConcRefinementRedZone, yellow_zone() * 2);
 }
 set_red_zone(MAX2<int>(G1ConcRefinementRedZone, yellow_zone()));
 _n_worker_threads = thread_num();
 // We need one extra thread to do the young gen rset size sampling.
 _n_threads = _n_worker_threads + 1;
 reset_threshold_step();
 _threads = NEW_C_HEAP_ARRAY(ConcurrentG1RefineThread*, _n_threads, mtGC);
 int worker_id_offset = (int)DirtyCardQueueSet::num_par_ids();
 ConcurrentG1RefineThread *next = NULL;
 for (int i = _n_threads - 1; i >= 0; i--) {
 ConcurrentG1RefineThread* t = new ConcurrentG1RefineThread(this, next, worker_id_offset, i);
 assert(t != NULL, "Conc refine should have been created");
 assert(t->cg1r() == this, "Conc refine thread should refer to this");
 } else {
 _thread_threshold_step = G1ConcRefinementThresholdStep;
 }
 }
-int ConcurrentG1Refine::thread_num() {
-return MAX2<int>((G1ConcRefinementThreads > 0) ? G1ConcRefinementThreads : ParallelGCThreads, 1);
-}
 void ConcurrentG1Refine::init() {
-if (G1ConcRSLogCacheSize > 0) {
+_hot_card_cache.initialize();
-_g1h = G1CollectedHeap::heap();
-_max_cards = _g1h->max_capacity() >> CardTableModRefBS::card_shift;
-_max_n_card_counts = _max_cards * G1MaxHotCardCountSizePercent / 100;
-size_t max_card_num = ((size_t)1 << (sizeof(unsigned)*BitsPerByte-1)) - 1;
-guarantee(_max_cards < max_card_num, "card_num representation");
-// We need _n_card_counts to be less than _max_n_card_counts here
-// so that the expansion call (below) actually allocates the
-// _counts and _epochs arrays.
-assert(_n_card_counts == 0, "pre-condition");
-assert(_max_n_card_counts > 0, "pre-condition");
-// Find the index into cache size array that is of a size that's
-// large enough to hold desired_sz.
-size_t desired_sz = _max_cards / InitialCacheFraction;
-int desired_sz_index = 0;
-while (_cc_cache_sizes[desired_sz_index] < desired_sz) {
-desired_sz_index += 1;
-assert(desired_sz_index <  MAX_CC_CACHE_INDEX, "invariant");
-}
-assert(desired_sz_index <  MAX_CC_CACHE_INDEX, "invariant");
-// If the desired_sz value is between two sizes then
-// _cc_cache_sizes[desired_sz_index-1] < desired_sz <= _cc_cache_sizes[desired_sz_index]
-// we will start with the lower size in the optimistic expectation that
-// we will not need to expand up. Note desired_sz_index could also be 0.
-if (desired_sz_index > 0 &&
-_cc_cache_sizes[desired_sz_index] > desired_sz) {
-desired_sz_index -= 1;
-}
-if (!expand_card_count_cache(desired_sz_index)) {
-// Allocation was unsuccessful - exit
-vm_exit_during_initialization("Could not reserve enough space for card count cache");
-}
-assert(_n_card_counts > 0, "post-condition");
-assert(_cache_size_index == desired_sz_index, "post-condition");
-Copy::fill_to_bytes(&_card_counts[0],
-_n_card_counts * sizeof(CardCountCacheEntry));
-Copy::fill_to_bytes(&_card_epochs[0], _n_card_counts * sizeof(CardEpochCacheEntry));
-ModRefBarrierSet* bs = _g1h->mr_bs();
-guarantee(bs->is_a(BarrierSet::CardTableModRef), "Precondition");
-_ct_bs = (CardTableModRefBS*)bs;
-_ct_bot = _ct_bs->byte_for_const(_g1h->reserved_region().start());
-_def_use_cache = true;
-_use_cache = true;
-_hot_cache_size = (1 << G1ConcRSLogCacheSize);
-_hot_cache = NEW_C_HEAP_ARRAY(jbyte*, _hot_cache_size, mtGC);
-_n_hot = 0;
-_hot_cache_idx = 0;
-// For refining the cards in the hot cache in parallel
-int n_workers = (ParallelGCThreads > 0 ?
-_g1h->workers()->total_workers() : 1);
-_hot_cache_par_chunk_size = MAX2(1, _hot_cache_size / n_workers);
-_hot_cache_par_claimed_idx = 0;
-}
 }
 void ConcurrentG1Refine::stop() {
 if (_threads != NULL) {
 for (int i = 0; i < _n_threads; i++) {
 }
 }
 }
 ConcurrentG1Refine::~ConcurrentG1Refine() {
-if (G1ConcRSLogCacheSize > 0) {
-// Please see the comment in allocate_card_count_cache
-// for why we call os::malloc() and os::free() directly.
-assert(_card_counts != NULL, "Logic");
-os::free(_card_counts, mtGC);
-assert(_card_epochs != NULL, "Logic");
-os::free(_card_epochs, mtGC);
-assert(_hot_cache != NULL, "Logic");
-FREE_C_HEAP_ARRAY(jbyte*, _hot_cache, mtGC);
-}
 if (_threads != NULL) {
 for (int i = 0; i < _n_threads; i++) {
 delete _threads[i];
 }
 FREE_C_HEAP_ARRAY(ConcurrentG1RefineThread*, _threads, mtGC);
 tc->do_thread(_threads[i]);
 }
 }
 }
-bool ConcurrentG1Refine::is_young_card(jbyte* card_ptr) {
+int ConcurrentG1Refine::thread_num() {
-HeapWord* start = _ct_bs->addr_for(card_ptr);
+int n_threads = (G1ConcRefinementThreads > 0) ? G1ConcRefinementThreads
-HeapRegion* r = _g1h->heap_region_containing(start);
+: ParallelGCThreads;
-if (r != NULL && r->is_young()) {
+return MAX2<int>(n_threads, 1);
-return true;
-}
-// This card is not associated with a heap region
-// so can't be young.
-return false;
-}
-jbyte* ConcurrentG1Refine::add_card_count(jbyte* card_ptr, int* count, bool* defer) {
-unsigned new_card_num = ptr_2_card_num(card_ptr);
-unsigned bucket = hash(new_card_num);
-assert(0 <= bucket && bucket < _n_card_counts, "Bounds");
-CardCountCacheEntry* count_ptr = &_card_counts[bucket];
-CardEpochCacheEntry* epoch_ptr = &_card_epochs[bucket];
-// We have to construct a new entry if we haven't updated the counts
-// during the current period, or if the count was updated for a
-// different card number.
-unsigned int new_epoch = (unsigned int) _n_periods;
-julong new_epoch_entry = make_epoch_entry(new_card_num, new_epoch);
-while (true) {
-// Fetch the previous epoch value
-julong prev_epoch_entry = epoch_ptr->_value;
-julong cas_res;
-if (extract_epoch(prev_epoch_entry) != new_epoch) {
-// This entry has not yet been updated during this period.
-// Note: we update the epoch value atomically to ensure
-// that there is only one winner that updates the cached
-// card_ptr value even though all the refine threads share
-// the same epoch value.
-cas_res = (julong) Atomic::cmpxchg((jlong) new_epoch_entry,
-(volatile jlong*)&epoch_ptr->_value,
-(jlong) prev_epoch_entry);
-if (cas_res == prev_epoch_entry) {
-// We have successfully won the race to update the
-// epoch and card_num value. Make it look like the
-// count and eviction count were previously cleared.
-count_ptr->_count = 1;
-count_ptr->_evict_count = 0;
-*count = 0;
-// We can defer the processing of card_ptr
-*defer = true;
-return card_ptr;
-}
-// We did not win the race to update the epoch field, so some other
-// thread must have done it. The value that gets returned by CAS
-// should be the new epoch value.
-assert(extract_epoch(cas_res) == new_epoch, "unexpected epoch");
-// We could 'continue' here or just re-read the previous epoch value
-prev_epoch_entry = epoch_ptr->_value;
-}
-// The epoch entry for card_ptr has been updated during this period.
-unsigned old_card_num = extract_card_num(prev_epoch_entry);
-// The card count that will be returned to caller
-*count = count_ptr->_count;
-// Are we updating the count for the same card?
-if (new_card_num == old_card_num) {
-// Same card - just update the count. We could have more than one
-// thread racing to update count for the current card. It should be
-// OK not to use a CAS as the only penalty should be some missed
-// increments of the count which delays identifying the card as "hot".
-if (*count < max_jubyte) count_ptr->_count++;
-// We can defer the processing of card_ptr
-*defer = true;
-return card_ptr;
-}
-// Different card - evict old card info
-if (count_ptr->_evict_count < max_jubyte) count_ptr->_evict_count++;
-if (count_ptr->_evict_count > G1CardCountCacheExpandThreshold) {
-// Trigger a resize the next time we clear
-_expand_card_counts = true;
-}
-cas_res = (julong) Atomic::cmpxchg((jlong) new_epoch_entry,
-(volatile jlong*)&epoch_ptr->_value,
-(jlong) prev_epoch_entry);
-if (cas_res == prev_epoch_entry) {
-// We successfully updated the card num value in the epoch entry
-count_ptr->_count = 0; // initialize counter for new card num
-jbyte* old_card_ptr = card_num_2_ptr(old_card_num);
-// Even though the region containg the card at old_card_num was not
-// in the young list when old_card_num was recorded in the epoch
-// cache it could have been added to the free list and subsequently
-// added to the young list in the intervening time. See CR 6817995.
-// We do not deal with this case here - it will be handled in
-// HeapRegion::oops_on_card_seq_iterate_careful after it has been
-// determined that the region containing the card has been allocated
-// to, and it's safe to check the young type of the region.
-// We do not want to defer processing of card_ptr in this case
-// (we need to refine old_card_ptr and card_ptr)
-*defer = false;
-return old_card_ptr;
-}
-// Someone else beat us - try again.
-}
-}
-jbyte* ConcurrentG1Refine::cache_insert(jbyte* card_ptr, bool* defer) {
-int count;
-jbyte* cached_ptr = add_card_count(card_ptr, &count, defer);
-assert(cached_ptr != NULL, "bad cached card ptr");
-// We've just inserted a card pointer into the card count cache
-// and got back the card that we just inserted or (evicted) the
-// previous contents of that count slot.
-// The card we got back could be in a young region. When the
-// returned card (if evicted) was originally inserted, we had
-// determined that its containing region was not young. However
-// it is possible for the region to be freed during a cleanup
-// pause, then reallocated and tagged as young which will result
-// in the returned card residing in a young region.
-//
-// We do not deal with this case here - the change from non-young
-// to young could be observed at any time - it will be handled in
-// HeapRegion::oops_on_card_seq_iterate_careful after it has been
-// determined that the region containing the card has been allocated
-// to.
-// The card pointer we obtained from card count cache is not hot
-// so do not store it in the cache; return it for immediate
-// refining.
-if (count < G1ConcRSHotCardLimit) {
-return cached_ptr;
-}
-// Otherwise, the pointer we got from the _card_counts cache is hot.
-jbyte* res = NULL;
-MutexLockerEx x(HotCardCache_lock, Mutex::_no_safepoint_check_flag);
-if (_n_hot == _hot_cache_size) {
-res = _hot_cache[_hot_cache_idx];
-_n_hot--;
-}
-// Now _n_hot < _hot_cache_size, and we can insert at _hot_cache_idx.
-_hot_cache[_hot_cache_idx] = cached_ptr;
-_hot_cache_idx++;
-if (_hot_cache_idx == _hot_cache_size) _hot_cache_idx = 0;
-_n_hot++;
-// The card obtained from the hot card cache could be in a young
-// region. See above on how this can happen.
-return res;
-}
-void ConcurrentG1Refine::clean_up_cache(int worker_i,
-G1RemSet* g1rs,
-DirtyCardQueue* into_cset_dcq) {
-assert(!use_cache(), "cache should be disabled");
-int start_idx;
-while ((start_idx = _hot_cache_par_claimed_idx) < _n_hot) { // read once
-int end_idx = start_idx + _hot_cache_par_chunk_size;
-if (start_idx ==
-Atomic::cmpxchg(end_idx, &_hot_cache_par_claimed_idx, start_idx)) {
-// The current worker has successfully claimed the chunk [start_idx..end_idx)
-end_idx = MIN2(end_idx, _n_hot);
-for (int i = start_idx; i < end_idx; i++) {
-jbyte* entry = _hot_cache[i];
-if (entry != NULL) {
-if (g1rs->concurrentRefineOneCard(entry, worker_i, true)) {
-// 'entry' contains references that point into the current
-// collection set. We need to record 'entry' in the DCQS
-// that's used for that purpose.
-//
-// The only time we care about recording cards that contain
-// references that point into the collection set is during
-// RSet updating while within an evacuation pause.
-// In this case worker_i should be the id of a GC worker thread
-assert(SafepointSynchronize::is_at_safepoint(), "not during an evacuation pause");
-assert(worker_i < (int) (ParallelGCThreads == 0 ? 1 : ParallelGCThreads), "incorrect worker id");
-into_cset_dcq->enqueue(entry);
-}
-}
-}
-}
-}
-}
-// The arrays used to hold the card counts and the epochs must have
-// a 1:1 correspondence. Hence they are allocated and freed together
-// Returns true if the allocations of both the counts and epochs
-// were successful; false otherwise.
-bool ConcurrentG1Refine::allocate_card_count_cache(size_t n,
-CardCountCacheEntry** counts,
-CardEpochCacheEntry** epochs) {
-// We call the allocation/free routines directly for the counts
-// and epochs arrays. The NEW_C_HEAP_ARRAY/FREE_C_HEAP_ARRAY
-// macros call AllocateHeap and FreeHeap respectively.
-// AllocateHeap will call vm_exit_out_of_memory in the event
-// of an allocation failure and abort the JVM. With the
-// _counts/epochs arrays we only need to abort the JVM if the
-// initial allocation of these arrays fails.
-//
-// Additionally AllocateHeap/FreeHeap do some tracing of
-// allocate/free calls so calling one without calling the
-// other can cause inconsistencies in the tracing. So we
-// call neither.
-assert(*counts == NULL, "out param");
-assert(*epochs == NULL, "out param");
-size_t counts_size = n * sizeof(CardCountCacheEntry);
-size_t epochs_size = n * sizeof(CardEpochCacheEntry);
-*counts = (CardCountCacheEntry*) os::malloc(counts_size, mtGC);
-if (*counts == NULL) {
-// allocation was unsuccessful
-return false;
-}
-*epochs = (CardEpochCacheEntry*) os::malloc(epochs_size, mtGC);
-if (*epochs == NULL) {
-// allocation was unsuccessful - free counts array
-assert(*counts != NULL, "must be");
-os::free(*counts, mtGC);
-*counts = NULL;
-return false;
-}
-// We successfully allocated both counts and epochs
-return true;
-}
-// Returns true if the card counts/epochs cache was
-// successfully expanded; false otherwise.
-bool ConcurrentG1Refine::expand_card_count_cache(int cache_size_idx) {
-// Can we expand the card count and epoch tables?
-if (_n_card_counts < _max_n_card_counts) {
-assert(cache_size_idx >= 0 && cache_size_idx  < MAX_CC_CACHE_INDEX, "oob");
-size_t cache_size = _cc_cache_sizes[cache_size_idx];
-// Make sure we don't go bigger than we will ever need
-cache_size = MIN2(cache_size, _max_n_card_counts);
-// Should we expand the card count and card epoch tables?
-if (cache_size > _n_card_counts) {
-// We have been asked to allocate new, larger, arrays for
-// the card counts and the epochs. Attempt the allocation
-// of both before we free the existing arrays in case
-// the allocation is unsuccessful...
-CardCountCacheEntry* counts = NULL;
-CardEpochCacheEntry* epochs = NULL;
-if (allocate_card_count_cache(cache_size, &counts, &epochs)) {
-// Allocation was successful.
-// We can just free the old arrays; we're
-// not interested in preserving the contents
-if (_card_counts != NULL) os::free(_card_counts, mtGC);
-if (_card_epochs != NULL) os::free(_card_epochs, mtGC);
-// Cache the size of the arrays and the index that got us there.
-_n_card_counts = cache_size;
-_cache_size_index = cache_size_idx;
-_card_counts = counts;
-_card_epochs = epochs;
-// We successfully allocated/expanded the caches.
-return true;
-}
-}
-}
-// We did not successfully expand the caches.
-return false;
-}
-void ConcurrentG1Refine::clear_and_record_card_counts() {
-if (G1ConcRSLogCacheSize == 0) {
-return;
-}
-double start = os::elapsedTime();
-if (_expand_card_counts) {
-int new_idx = _cache_size_index + 1;
-if (expand_card_count_cache(new_idx)) {
-// Allocation was successful and  _n_card_counts has
-// been updated to the new size. We only need to clear
-// the epochs so we don't read a bogus epoch value
-// when inserting a card into the hot card cache.
-Copy::fill_to_bytes(&_card_epochs[0], _n_card_counts * sizeof(CardEpochCacheEntry));
-}
-_expand_card_counts = false;
-}
-int this_epoch = (int) _n_periods;
-assert((this_epoch+1) <= max_jint, "to many periods");
-// Update epoch
-_n_periods++;
-double cc_clear_time_ms = (os::elapsedTime() - start) * 1000;
-_g1h->g1_policy()->phase_times()->record_cc_clear_time_ms(cc_clear_time_ms);
 }
 void ConcurrentG1Refine::print_worker_threads_on(outputStream* st) const {
 for (int i = 0; i < _n_threads; ++i) {
 _threads[i]->print_on(st);

Mercurial > jdk8-mips64-public > hotspot / file comparison

comparison: src/share/vm/gc_implementation/g1/concurrentG1Refine.cpp

src/share/vm/gc_implementation/g1/concurrentG1Refine.cpp