jdk8-mips64-public/hotspot: src/share/vm/gc_implementation/g1/dirtyCardQueue.cpp@e7d0505c8a30 (annotated)

src/share/vm/gc_implementation/g1/dirtyCardQueue.cpp@e7d0505c8a30 (annotated)

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

Fri, 10 Oct 2014 15:51:58 +0200

author: tschatzl
date: Fri, 10 Oct 2014 15:51:58 +0200
changeset 7257: e7d0505c8a30
parent 6930: 570cb6369f17
child 7535: 7ae4e26cb1e0
child 8662: 9975dd8382d5
permissions: -rw-r--r--

8059758: Footprint regressions with JDK-8038423
Summary: Changes in JDK-8038423 always initialize (zero out) virtual memory used for auxiliary data structures. This causes a footprint regression for G1 in startup benchmarks. This is because they do not touch that memory at all, so the operating system does not actually commit these pages. The fix is to, if the initialization value of the data structures matches the default value of just committed memory (=0), do not do anything.
Reviewed-by: jwilhelm, brutisso

 /*
  * Copyright (c) 2001, 2010, 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/heapRegionRemSet.hpp"
 #include "runtime/atomic.hpp"
 #include "runtime/mutexLocker.hpp"
 #include "runtime/safepoint.hpp"
 #include "runtime/thread.inline.hpp"
 #include "utilities/workgroup.hpp"
 bool DirtyCardQueue::apply_closure(CardTableEntryClosure* cl,
                                    bool consume,
                                    uint worker_i) {
   bool res = true;
   if (_buf != NULL) {
     res = apply_closure_to_buffer(cl, _buf, _index, _sz,
                                   consume,
                                   worker_i);
     if (res && consume) _index = _sz;
   }
   return res;
 }
 bool DirtyCardQueue::apply_closure_to_buffer(CardTableEntryClosure* cl,
                                              void** buf,
                                              size_t index, size_t sz,
                                              bool consume,
                                              uint worker_i) {
   if (cl == NULL) return true;
   for (size_t i = index; i < sz; i += oopSize) {
     int ind = byte_index_to_index((int)i);
     jbyte* card_ptr = (jbyte*)buf[ind];
     if (card_ptr != NULL) {
       // Set the entry to null, so we don't do it again (via the test
       // above) if we reconsider this buffer.
       if (consume) buf[ind] = NULL;
       if (!cl->do_card_ptr(card_ptr, worker_i)) return false;
     }
   }
   return true;
 }
 #ifdef _MSC_VER // the use of 'this' below gets a warning, make it go away
 #pragma warning( disable:4355 ) // 'this' : used in base member initializer list
 #endif // _MSC_VER
 DirtyCardQueueSet::DirtyCardQueueSet(bool notify_when_complete) :
   PtrQueueSet(notify_when_complete),
   _mut_process_closure(NULL),
   _shared_dirty_card_queue(this, true /*perm*/),
   _free_ids(NULL),
   _processed_buffers_mut(0), _processed_buffers_rs_thread(0)
 {
   _all_active = true;
 }
 // Determines how many mutator threads can process the buffers in parallel.
 uint DirtyCardQueueSet::num_par_ids() {
   return (uint)os::processor_count();
 }
 void DirtyCardQueueSet::initialize(CardTableEntryClosure* cl, Monitor* cbl_mon, Mutex* fl_lock,
                                    int process_completed_threshold,
                                    int max_completed_queue,
                                    Mutex* lock, PtrQueueSet* fl_owner) {
   _mut_process_closure = cl;
   PtrQueueSet::initialize(cbl_mon, fl_lock, process_completed_threshold,
                           max_completed_queue, fl_owner);
   set_buffer_size(G1UpdateBufferSize);
   _shared_dirty_card_queue.set_lock(lock);
   _free_ids = new FreeIdSet((int) num_par_ids(), _cbl_mon);
 }
 void DirtyCardQueueSet::handle_zero_index_for_thread(JavaThread* t) {
   t->dirty_card_queue().handle_zero_index();
 }
 void DirtyCardQueueSet::iterate_closure_all_threads(CardTableEntryClosure* cl,
                                                     bool consume,
                                                     uint worker_i) {
   assert(SafepointSynchronize::is_at_safepoint(), "Must be at safepoint.");
   for(JavaThread* t = Threads::first(); t; t = t->next()) {
     bool b = t->dirty_card_queue().apply_closure(cl, consume);
     guarantee(b, "Should not be interrupted.");
   }
   bool b = shared_dirty_card_queue()->apply_closure(cl,
                                                     consume,
                                                     worker_i);
   guarantee(b, "Should not be interrupted.");
 }
 bool DirtyCardQueueSet::mut_process_buffer(void** buf) {
   // Used to determine if we had already claimed a par_id
   // before entering this method.
   bool already_claimed = false;
   // We grab the current JavaThread.
   JavaThread* thread = JavaThread::current();
   // We get the the number of any par_id that this thread
   // might have already claimed.
   uint worker_i = thread->get_claimed_par_id();
   // If worker_i is not UINT_MAX then the thread has already claimed
   // a par_id. We make note of it using the already_claimed value
   if (worker_i != UINT_MAX) {
     already_claimed = true;
   } else {
     // Otherwise we need to claim a par id
     worker_i = _free_ids->claim_par_id();
     // And store the par_id value in the thread
     thread->set_claimed_par_id(worker_i);
   }
   bool b = false;
   if (worker_i != UINT_MAX) {
     b = DirtyCardQueue::apply_closure_to_buffer(_mut_process_closure, buf, 0,
                                                 _sz, true, worker_i);
     if (b) Atomic::inc(&_processed_buffers_mut);
     // If we had not claimed an id before entering the method
     // then we must release the id.
     if (!already_claimed) {
       // we release the id
       _free_ids->release_par_id(worker_i);
       // and set the claimed_id in the thread to UINT_MAX
       thread->set_claimed_par_id(UINT_MAX);
     }
   }
   return b;
 }
 BufferNode*
 DirtyCardQueueSet::get_completed_buffer(int stop_at) {
   BufferNode* nd = NULL;
   MutexLockerEx x(_cbl_mon, Mutex::_no_safepoint_check_flag);
   if ((int)_n_completed_buffers <= stop_at) {
     _process_completed = false;
     return NULL;
   }
   if (_completed_buffers_head != NULL) {
     nd = _completed_buffers_head;
     _completed_buffers_head = nd->next();
     if (_completed_buffers_head == NULL)
       _completed_buffers_tail = NULL;
     _n_completed_buffers--;
     assert(_n_completed_buffers >= 0, "Invariant");
   }
   debug_only(assert_completed_buffer_list_len_correct_locked());
   return nd;
 }
 bool DirtyCardQueueSet::
 apply_closure_to_completed_buffer_helper(CardTableEntryClosure* cl,
                                          uint worker_i,
                                          BufferNode* nd) {
   if (nd != NULL) {
     void **buf = BufferNode::make_buffer_from_node(nd);
     size_t index = nd->index();
     bool b =
       DirtyCardQueue::apply_closure_to_buffer(cl, buf,
                                               index, _sz,
                                               true, worker_i);
     if (b) {
       deallocate_buffer(buf);
       return true;  // In normal case, go on to next buffer.
     } else {
       enqueue_complete_buffer(buf, index);
       return false;
     }
   } else {
     return false;
   }
 }
 bool DirtyCardQueueSet::apply_closure_to_completed_buffer(CardTableEntryClosure* cl,
                                                           uint worker_i,
                                                           int stop_at,
                                                           bool during_pause) {
   assert(!during_pause || stop_at == 0, "Should not leave any completed buffers during a pause");
   BufferNode* nd = get_completed_buffer(stop_at);
   bool res = apply_closure_to_completed_buffer_helper(cl, worker_i, nd);
   if (res) Atomic::inc(&_processed_buffers_rs_thread);
   return res;
 }
 void DirtyCardQueueSet::apply_closure_to_all_completed_buffers(CardTableEntryClosure* cl) {
   BufferNode* nd = _completed_buffers_head;
   while (nd != NULL) {
     bool b =
       DirtyCardQueue::apply_closure_to_buffer(cl,
                                               BufferNode::make_buffer_from_node(nd),
 , _sz, false);
     guarantee(b, "Should not stop early.");
     nd = nd->next();
   }
 }
 void DirtyCardQueueSet::par_apply_closure_to_all_completed_buffers(CardTableEntryClosure* cl) {
   BufferNode* nd = _cur_par_buffer_node;
   while (nd != NULL) {
     BufferNode* next = (BufferNode*)nd->next();
     BufferNode* actual = (BufferNode*)Atomic::cmpxchg_ptr((void*)next, (volatile void*)&_cur_par_buffer_node, (void*)nd);
     if (actual == nd) {
       bool b =
         DirtyCardQueue::apply_closure_to_buffer(cl,
                                                 BufferNode::make_buffer_from_node(actual),
 , _sz, false);
       guarantee(b, "Should not stop early.");
       nd = next;
     } else {
       nd = actual;
     }
   }
 }
 // Deallocates any completed log buffers
 void DirtyCardQueueSet::clear() {
   BufferNode* buffers_to_delete = NULL;
   {
     MutexLockerEx x(_cbl_mon, Mutex::_no_safepoint_check_flag);
     while (_completed_buffers_head != NULL) {
       BufferNode* nd = _completed_buffers_head;
       _completed_buffers_head = nd->next();
       nd->set_next(buffers_to_delete);
       buffers_to_delete = nd;
     }
     _n_completed_buffers = 0;
     _completed_buffers_tail = NULL;
     debug_only(assert_completed_buffer_list_len_correct_locked());
   }
   while (buffers_to_delete != NULL) {
     BufferNode* nd = buffers_to_delete;
     buffers_to_delete = nd->next();
     deallocate_buffer(BufferNode::make_buffer_from_node(nd));
   }
 }
 void DirtyCardQueueSet::abandon_logs() {
   assert(SafepointSynchronize::is_at_safepoint(), "Must be at safepoint.");
   clear();
   // Since abandon is done only at safepoints, we can safely manipulate
   // these queues.
   for (JavaThread* t = Threads::first(); t; t = t->next()) {
     t->dirty_card_queue().reset();
   }
   shared_dirty_card_queue()->reset();
 }
 void DirtyCardQueueSet::concatenate_logs() {
   // Iterate over all the threads, if we find a partial log add it to
   // the global list of logs.  Temporarily turn off the limit on the number
   // of outstanding buffers.
   int save_max_completed_queue = _max_completed_queue;
   _max_completed_queue = max_jint;
   assert(SafepointSynchronize::is_at_safepoint(), "Must be at safepoint.");
   for (JavaThread* t = Threads::first(); t; t = t->next()) {
     DirtyCardQueue& dcq = t->dirty_card_queue();
     if (dcq.size() != 0) {
       void **buf = t->dirty_card_queue().get_buf();
       // We must NULL out the unused entries, then enqueue.
       for (size_t i = 0; i < t->dirty_card_queue().get_index(); i += oopSize) {
         buf[PtrQueue::byte_index_to_index((int)i)] = NULL;
       }
       enqueue_complete_buffer(dcq.get_buf(), dcq.get_index());
       dcq.reinitialize();
     }
   }
   if (_shared_dirty_card_queue.size() != 0) {
     enqueue_complete_buffer(_shared_dirty_card_queue.get_buf(),
                             _shared_dirty_card_queue.get_index());
     _shared_dirty_card_queue.reinitialize();
   }
   // Restore the completed buffer queue limit.
   _max_completed_queue = save_max_completed_queue;
 }

Mercurial > jdk8-mips64-public > hotspot / annotate

src/share/vm/gc_implementation/g1/dirtyCardQueue.cpp@e7d0505c8a30 (annotated)

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