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

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

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

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 7476: c2844108a708
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, 2012, 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
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 #ifndef SHARE_VM_GC_IMPLEMENTATION_G1_DIRTYCARDQUEUE_HPP
 #define SHARE_VM_GC_IMPLEMENTATION_G1_DIRTYCARDQUEUE_HPP
 #include "gc_implementation/g1/ptrQueue.hpp"
 #include "memory/allocation.hpp"
 class FreeIdSet;
 // A closure class for processing card table entries.  Note that we don't
 // require these closure objects to be stack-allocated.
 class CardTableEntryClosure: public CHeapObj<mtGC> {
 public:
   // Process the card whose card table entry is "card_ptr".  If returns
   // "false", terminate the iteration early.
   virtual bool do_card_ptr(jbyte* card_ptr, uint worker_i = 0) = 0;
 };
 // A ptrQueue whose elements are "oops", pointers to object heads.
 class DirtyCardQueue: public PtrQueue {
 public:
   DirtyCardQueue(PtrQueueSet* qset_, bool perm = false) :
     // Dirty card queues are always active, so we create them with their
     // active field set to true.
     PtrQueue(qset_, perm, true /* active */) { }
   // Apply the closure to all elements, and reset the index to make the
   // buffer empty.  If a closure application returns "false", return
   // "false" immediately, halting the iteration.  If "consume" is true,
   // deletes processed entries from logs.
   bool apply_closure(CardTableEntryClosure* cl,
                      bool consume = true,
                      uint worker_i = 0);
   // Apply the closure to all elements of "buf", down to "index"
   // (inclusive.)  If returns "false", then a closure application returned
   // "false", and we return immediately.  If "consume" is true, entries are
   // set to NULL as they are processed, so they will not be processed again
   // later.
   static bool apply_closure_to_buffer(CardTableEntryClosure* cl,
                                       void** buf, size_t index, size_t sz,
                                       bool consume = true,
                                       uint worker_i = 0);
   void **get_buf() { return _buf;}
   void set_buf(void **buf) {_buf = buf;}
   size_t get_index() { return _index;}
   void reinitialize() { _buf = 0; _sz = 0; _index = 0;}
 };
 class DirtyCardQueueSet: public PtrQueueSet {
   // The closure used in mut_process_buffer().
   CardTableEntryClosure* _mut_process_closure;
   DirtyCardQueue _shared_dirty_card_queue;
   // Override.
   bool mut_process_buffer(void** buf);
   // Protected by the _cbl_mon.
   FreeIdSet* _free_ids;
   // The number of completed buffers processed by mutator and rs thread,
   // respectively.
   jint _processed_buffers_mut;
   jint _processed_buffers_rs_thread;
   // Current buffer node used for parallel iteration.
   BufferNode* volatile _cur_par_buffer_node;
 public:
   DirtyCardQueueSet(bool notify_when_complete = true);
   void initialize(CardTableEntryClosure* cl, Monitor* cbl_mon, Mutex* fl_lock,
                   int process_completed_threshold,
                   int max_completed_queue,
                   Mutex* lock, PtrQueueSet* fl_owner = NULL);
   // The number of parallel ids that can be claimed to allow collector or
   // mutator threads to do card-processing work.
   static uint num_par_ids();
   static void handle_zero_index_for_thread(JavaThread* t);
   // Apply the given closure to all entries in all currently-active buffers.
   // This should only be applied at a safepoint. (Currently must not be called
   // in parallel; this should change in the future.)  If "consume" is true,
   // processed entries are discarded.
   void iterate_closure_all_threads(CardTableEntryClosure* cl,
                                    bool consume = true,
                                    uint worker_i = 0);
   // If there exists some completed buffer, pop it, then apply the
   // specified closure to all its elements, nulling out those elements
   // processed.  If all elements are processed, returns "true".  If no
   // completed buffers exist, returns false.  If a completed buffer exists,
   // but is only partially completed before a "yield" happens, the
   // partially completed buffer (with its processed elements set to NULL)
   // is returned to the completed buffer set, and this call returns false.
   bool apply_closure_to_completed_buffer(CardTableEntryClosure* cl,
                                          uint worker_i = 0,
                                          int stop_at = 0,
                                          bool during_pause = false);
   // Helper routine for the above.
   bool apply_closure_to_completed_buffer_helper(CardTableEntryClosure* cl,
                                                 uint worker_i,
                                                 BufferNode* nd);
   BufferNode* get_completed_buffer(int stop_at);
   // Applies the current closure to all completed buffers,
   // non-consumptively.
   void apply_closure_to_all_completed_buffers(CardTableEntryClosure* cl);
   void reset_for_par_iteration() { _cur_par_buffer_node = _completed_buffers_head; }
   // Applies the current closure to all completed buffers, non-consumptively.
   // Parallel version.
   void par_apply_closure_to_all_completed_buffers(CardTableEntryClosure* cl);
   DirtyCardQueue* shared_dirty_card_queue() {
     return &_shared_dirty_card_queue;
   }
   // Deallocate any completed log buffers
   void clear();
   // If a full collection is happening, reset partial logs, and ignore
   // completed ones: the full collection will make them all irrelevant.
   void abandon_logs();
   // If any threads have partial logs, add them to the global list of logs.
   void concatenate_logs();
   void clear_n_completed_buffers() { _n_completed_buffers = 0;}
   jint processed_buffers_mut() {
     return _processed_buffers_mut;
   }
   jint processed_buffers_rs_thread() {
     return _processed_buffers_rs_thread;
   }
 };
 #endif // SHARE_VM_GC_IMPLEMENTATION_G1_DIRTYCARDQUEUE_HPP

Mercurial > jdk8-mips64-public > hotspot / annotate

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

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