jdk8-mips64-public/hotspot: src/share/vm/gc_implementation/g1/heapRegionSet.inline.hpp@e7d0505c8a30

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

     1 /*

     2  * Copyright (c) 2011, 2014, Oracle and/or its affiliates. All rights reserved.

     3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

     4  *

     5  * This code is free software; you can redistribute it and/or modify it

     6  * under the terms of the GNU General Public License version 2 only, as

     7  * published by the Free Software Foundation.

     8  *

     9  * This code is distributed in the hope that it will be useful, but WITHOUT

    10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or

    11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License

    12  * version 2 for more details (a copy is included in the LICENSE file that

    13  * accompanied this code).

    14  *

    15  * You should have received a copy of the GNU General Public License version

    16  * 2 along with this work; if not, write to the Free Software Foundation,

    17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

    18  *

    19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA

    20  * or visit www.oracle.com if you need additional information or have any

    21  * questions.

    22  *

    23  */

    25 #ifndef SHARE_VM_GC_IMPLEMENTATION_G1_HEAPREGIONSET_INLINE_HPP

    26 #define SHARE_VM_GC_IMPLEMENTATION_G1_HEAPREGIONSET_INLINE_HPP

    28 #include "gc_implementation/g1/heapRegionSet.hpp"

    30 inline void HeapRegionSetBase::add(HeapRegion* hr) {

    31   check_mt_safety();

    32   assert(hr->containing_set() == NULL, hrs_ext_msg(this, "should not already have a containing set %u"));

    33   assert(hr->next() == NULL, hrs_ext_msg(this, "should not already be linked"));

    34   assert(hr->prev() == NULL, hrs_ext_msg(this, "should not already be linked"));

    36   _count.increment(1u, hr->capacity());

    37   hr->set_containing_set(this);

    38   verify_region(hr);

    39 }

    41 inline void HeapRegionSetBase::remove(HeapRegion* hr) {

    42   check_mt_safety();

    43   verify_region(hr);

    44   assert(hr->next() == NULL, hrs_ext_msg(this, "should already be unlinked"));

    45   assert(hr->prev() == NULL, hrs_ext_msg(this, "should already be unlinked"));

    47   hr->set_containing_set(NULL);

    48   assert(_count.length() > 0, hrs_ext_msg(this, "pre-condition"));

    49   _count.decrement(1u, hr->capacity());

    50 }

    52 inline void FreeRegionList::add_ordered(HeapRegion* hr) {

    53   assert((length() == 0 && _head == NULL && _tail == NULL && _last == NULL) ||

    54          (length() >  0 && _head != NULL && _tail != NULL),

    55          hrs_ext_msg(this, "invariant"));

    56   // add() will verify the region and check mt safety.

    57   add(hr);

    59   // Now link the region

    60   if (_head != NULL) {

    61     HeapRegion* curr;

    63     if (_last != NULL && _last->hrm_index() < hr->hrm_index()) {

    64       curr = _last;

    65     } else {

    66       curr = _head;

    67     }

    69     // Find first entry with a Region Index larger than entry to insert.

    70     while (curr != NULL && curr->hrm_index() < hr->hrm_index()) {

    71       curr = curr->next();

    72     }

    74     hr->set_next(curr);

    76     if (curr == NULL) {

    77       // Adding at the end

    78       hr->set_prev(_tail);

    79       _tail->set_next(hr);

    80       _tail = hr;

    81     } else if (curr->prev() == NULL) {

    82       // Adding at the beginning

    83       hr->set_prev(NULL);

    84       _head = hr;

    85       curr->set_prev(hr);

    86     } else {

    87       hr->set_prev(curr->prev());

    88       hr->prev()->set_next(hr);

    89       curr->set_prev(hr);

    90     }

    91   } else {

    92     // The list was empty

    93     _tail = hr;

    94     _head = hr;

    95   }

    96   _last = hr;

    97 }

    99 inline HeapRegion* FreeRegionList::remove_from_head_impl() {

   100   HeapRegion* result = _head;

   101   _head = result->next();

   102   if (_head == NULL) {

   103     _tail = NULL;

   104   } else {

   105     _head->set_prev(NULL);

   106   }

   107   result->set_next(NULL);

   108   return result;

   109 }

   111 inline HeapRegion* FreeRegionList::remove_from_tail_impl() {

   112   HeapRegion* result = _tail;

   114   _tail = result->prev();

   115   if (_tail == NULL) {

   116     _head = NULL;

   117   } else {

   118     _tail->set_next(NULL);

   119   }

   120   result->set_prev(NULL);

   121   return result;

   122 }

   124 inline HeapRegion* FreeRegionList::remove_region(bool from_head) {

   125   check_mt_safety();

   126   verify_optional();

   128   if (is_empty()) {

   129     return NULL;

   130   }

   131   assert(length() > 0 && _head != NULL && _tail != NULL,

   132          hrs_ext_msg(this, "invariant"));

   134   HeapRegion* hr;

   136   if (from_head) {

   137     hr = remove_from_head_impl();

   138   } else {

   139     hr = remove_from_tail_impl();

   140   }

   142   if (_last == hr) {

   143     _last = NULL;

   144   }

   146   // remove() will verify the region and check mt safety.

   147   remove(hr);

   148   return hr;

   149 }

   151 #endif // SHARE_VM_GC_IMPLEMENTATION_G1_HEAPREGIONSET_INLINE_HPP

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

src/share/vm/gc_implementation/g1/heapRegionSet.inline.hpp@e7d0505c8a30

src/share/vm/gc_implementation/g1/heapRegionSet.inline.hpp