jdk8-mips64-public/hotspot: src/share/vm/gc_implementation/concurrentMarkSweep/freeChunk.cpp@e018e6884bd8

6631166: CMS: better heuristics when combatting fragmentation
Summary: Autonomic per-worker free block cache sizing, tunable coalition policies, fixes to per-size block statistics, retuned gain and bandwidth of some feedback loop filters to allow quicker reactivity to abrupt changes in ambient demand, and other heuristics to reduce fragmentation of the CMS old gen. Also tightened some assertions, including those related to locking.
Reviewed-by: jmasa

     1 /*

     2  * Copyright 2001-2008 Sun Microsystems, Inc.  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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,

    20  * CA 95054 USA or visit www.sun.com if you need additional information or

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    23  */

    25 # include "incls/_precompiled.incl"

    26 # include "incls/_freeChunk.cpp.incl"

    28 #ifndef PRODUCT

    30 #define baadbabeHeapWord badHeapWordVal

    31 #define deadbeefHeapWord 0xdeadbeef

    33 size_t const FreeChunk::header_size() {

    34   return sizeof(FreeChunk)/HeapWordSize;

    35 }

    37 void FreeChunk::mangleAllocated(size_t size) {

    38   // mangle all but the header of a just-allocated block

    39   // of storage

    40   assert(size >= MinChunkSize, "smallest size of object");

    41   // we can't assert that _size == size because this may be an

    42   // allocation out of a linear allocation block

    43   assert(sizeof(FreeChunk) % HeapWordSize == 0,

    44          "shouldn't write beyond chunk");

    45   HeapWord* addr = (HeapWord*)this;

    46   size_t hdr = header_size();

    47   Copy::fill_to_words(addr + hdr, size - hdr, baadbabeHeapWord);

    48 }

    50 void FreeChunk::mangleFreed(size_t sz) {

    51   assert(baadbabeHeapWord != deadbeefHeapWord, "Need distinct patterns");

    52   // mangle all but the header of a just-freed block of storage

    53   // just prior to passing it to the storage dictionary

    54   assert(sz >= MinChunkSize, "smallest size of object");

    55   assert(sz == size(), "just checking");

    56   HeapWord* addr = (HeapWord*)this;

    57   size_t hdr = header_size();

    58   Copy::fill_to_words(addr + hdr, sz - hdr, deadbeefHeapWord);

    59 }

    61 void FreeChunk::verifyList() const {

    62   FreeChunk* nextFC = next();

    63   if (nextFC != NULL) {

    64     assert(this == nextFC->prev(), "broken chain");

    65     assert(size() == nextFC->size(), "wrong size");

    66     nextFC->verifyList();

    67   }

    68 }

    69 #endif

    71 void FreeChunk::print_on(outputStream* st) {

    72   st->print_cr("Next: " PTR_FORMAT " Prev: " PTR_FORMAT " %s",

    73     next(), prev(), cantCoalesce() ? "[can't coalesce]" : "");

    74 }

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

src/share/vm/gc_implementation/concurrentMarkSweep/freeChunk.cpp@e018e6884bd8

src/share/vm/gc_implementation/concurrentMarkSweep/freeChunk.cpp