jdk8-mips64-public/hotspot: src/share/vm/gc_implementation/g1/g1HotCardCache.cpp@ae374055ebce (annotated)

src/share/vm/gc_implementation/g1/g1HotCardCache.cpp@ae374055ebce (annotated)

src/share/vm/gc_implementation/g1/g1HotCardCache.cpp

Thu, 18 Sep 2014 11:27:59 +0200

author: mlarsson
date: Thu, 18 Sep 2014 11:27:59 +0200
changeset 7652: ae374055ebce
parent 7195: c02ec279b062
child 7653: b6a1bf5222c5
permissions: -rw-r--r--

8053998: Hot card cache flush chunk size too coarse grained
Summary: Changed the chunk size to a smaller fixed number.
Reviewed-by: tschatzl, mgerdin

 /*
  * Copyright (c) 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.
  *
  * 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 "gc_implementation/g1/dirtyCardQueue.hpp"
 #include "gc_implementation/g1/g1CollectedHeap.inline.hpp"
 #include "gc_implementation/g1/g1HotCardCache.hpp"
 #include "gc_implementation/g1/g1RemSet.hpp"
 #include "runtime/atomic.hpp"
 G1HotCardCache::G1HotCardCache(G1CollectedHeap *g1h):
   _g1h(g1h), _hot_cache(NULL), _use_cache(false), _card_counts(g1h) {}
 void G1HotCardCache::initialize(G1RegionToSpaceMapper* card_counts_storage) {
   if (default_use_cache()) {
     _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
     _hot_cache_par_chunk_size = (int)(ParallelGCThreads > 0 ? ClaimChunkSize : _hot_cache_size);
     _hot_cache_par_claimed_idx = 0;
     _card_counts.initialize(card_counts_storage);
   }
 }
 G1HotCardCache::~G1HotCardCache() {
   if (default_use_cache()) {
     assert(_hot_cache != NULL, "Logic");
     FREE_C_HEAP_ARRAY(jbyte*, _hot_cache, mtGC);
   }
 }
 jbyte* G1HotCardCache::insert(jbyte* card_ptr) {
   uint count = _card_counts.add_card_count(card_ptr);
   if (!_card_counts.is_hot(count)) {
     // The card is not hot so do not store it in the cache;
     // return it for immediate refining.
     return card_ptr;
   }
   // Otherwise, the card 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] = card_ptr;
   _hot_cache_idx++;
   if (_hot_cache_idx == _hot_cache_size) {
     // Wrap around
     _hot_cache_idx = 0;
   }
   _n_hot++;
   return res;
 }
 void G1HotCardCache::drain(uint worker_i,
                            G1RemSet* g1rs,
                            DirtyCardQueue* into_cset_dcq) {
   if (!default_use_cache()) {
     assert(_hot_cache == NULL, "Logic");
     return;
   }
   assert(_hot_cache != NULL, "Logic");
   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* card_ptr = _hot_cache[i];
         if (card_ptr != NULL) {
           if (g1rs->refine_card(card_ptr, worker_i, true)) {
             // The part of the heap spanned by the card contains references
             // that point into the current collection set.
             // We need to record the card pointer in the DirtyCardQueueSet
             // that we use for such cards.
             //
             // 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(), "Should be at a safepoint");
             assert(worker_i < (ParallelGCThreads == 0 ? 1 : ParallelGCThreads),
                    err_msg("incorrect worker id: "UINT32_FORMAT, worker_i));
             into_cset_dcq->enqueue(card_ptr);
           }
         }
       }
     }
   }
   // The existing entries in the hot card cache, which were just refined
   // above, are discarded prior to re-enabling the cache near the end of the GC.
 }
 void G1HotCardCache::reset_card_counts(HeapRegion* hr) {
   _card_counts.clear_region(hr);
 }
 void G1HotCardCache::reset_card_counts() {
   _card_counts.clear_all();
 }

Mercurial > jdk8-mips64-public > hotspot / annotate

src/share/vm/gc_implementation/g1/g1HotCardCache.cpp@ae374055ebce (annotated)

src/share/vm/gc_implementation/g1/g1HotCardCache.cpp