src/share/vm/gc_implementation/parallelScavenge/asPSOldGen.cpp

Fri, 16 Jul 2010 21:33:21 -0700

author
jcoomes
date
Fri, 16 Jul 2010 21:33:21 -0700
changeset 2020
a93a9eda13f7
parent 1907
c18cbe5936b8
child 2314
f95d63e2154a
permissions
-rw-r--r--

6962947: shared TaskQueue statistics
Reviewed-by: tonyp, ysr

     1 /*
     2  * Copyright (c) 2003, 2006, 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 # include "incls/_precompiled.incl"
    26 # include "incls/_asPSOldGen.cpp.incl"
    28 // Whereas PSOldGen takes the maximum size of the generation
    29 // (which doesn't change in the case of PSOldGen) as a parameter,
    30 // ASPSOldGen takes the upper limit on the size of
    31 // the generation as a parameter.  In ASPSOldGen the
    32 // maximum size of the generation can change as the boundary
    33 // moves.  The "maximum size of the generation" is still a valid
    34 // concept since the generation can grow and shrink within that
    35 // maximum.  There are lots of useful checks that use that
    36 // maximum.  In PSOldGen the method max_gen_size() returns
    37 // _max_gen_size (as set by the PSOldGen constructor).  This
    38 // is how it always worked.  In ASPSOldGen max_gen_size()
    39 // returned the size of the reserved space for the generation.
    40 // That can change as the boundary moves.  Below the limit of
    41 // the size of the generation is passed to the PSOldGen constructor
    42 // for "_max_gen_size" (have to pass something) but it is not used later.
    43 //
    44 ASPSOldGen::ASPSOldGen(size_t initial_size,
    45                        size_t min_size,
    46                        size_t size_limit,
    47                        const char* gen_name,
    48                        int level) :
    49   PSOldGen(initial_size, min_size, size_limit, gen_name, level),
    50   _gen_size_limit(size_limit)
    52 {}
    54 ASPSOldGen::ASPSOldGen(PSVirtualSpace* vs,
    55                        size_t initial_size,
    56                        size_t min_size,
    57                        size_t size_limit,
    58                        const char* gen_name,
    59                        int level) :
    60   PSOldGen(initial_size, min_size, size_limit, gen_name, level),
    61   _gen_size_limit(size_limit)
    63 {
    64   _virtual_space = vs;
    65 }
    67 void ASPSOldGen::reset_after_change() {
    68   _reserved = MemRegion((HeapWord*)virtual_space()->low_boundary(),
    69                         (HeapWord*)virtual_space()->high_boundary());
    70   post_resize();
    71 }
    74 size_t ASPSOldGen::available_for_expansion() {
    75   assert(virtual_space()->is_aligned(gen_size_limit()), "not aligned");
    76   assert(gen_size_limit() >= virtual_space()->committed_size(), "bad gen size");
    78   ParallelScavengeHeap* heap = (ParallelScavengeHeap*)Universe::heap();
    79   size_t result =  gen_size_limit() - virtual_space()->committed_size();
    80   size_t result_aligned = align_size_down(result, heap->old_gen_alignment());
    81   return result_aligned;
    82 }
    84 size_t ASPSOldGen::available_for_contraction() {
    85   size_t uncommitted_bytes = virtual_space()->uncommitted_size();
    86   if (uncommitted_bytes != 0) {
    87     return uncommitted_bytes;
    88   }
    90   ParallelScavengeHeap* heap = (ParallelScavengeHeap*)Universe::heap();
    91   const size_t gen_alignment = heap->old_gen_alignment();
    92   PSAdaptiveSizePolicy* policy = heap->size_policy();
    93   const size_t working_size =
    94     used_in_bytes() + (size_t) policy->avg_promoted()->padded_average();
    95   const size_t working_aligned = align_size_up(working_size, gen_alignment);
    96   const size_t working_or_min = MAX2(working_aligned, min_gen_size());
    97   if (working_or_min > reserved().byte_size()) {
    98     // If the used or minimum gen size (aligned up) is greater
    99     // than the total reserved size, then the space available
   100     // for contraction should (after proper alignment) be 0
   101     return 0;
   102   }
   103   const size_t max_contraction =
   104     reserved().byte_size() - working_or_min;
   106   // Use the "increment" fraction instead of the "decrement" fraction
   107   // to allow the other gen to expand more aggressively.  The
   108   // "decrement" fraction is conservative because its intent is to
   109   // only reduce the footprint.
   111   size_t result = policy->promo_increment_aligned_down(max_contraction);
   112   // Also adjust for inter-generational alignment
   113   size_t result_aligned = align_size_down(result, gen_alignment);
   114   if (PrintAdaptiveSizePolicy && Verbose) {
   115     gclog_or_tty->print_cr("\nASPSOldGen::available_for_contraction:"
   116       " %d K / 0x%x", result_aligned/K, result_aligned);
   117     gclog_or_tty->print_cr(" reserved().byte_size() %d K / 0x%x ",
   118       reserved().byte_size()/K, reserved().byte_size());
   119     size_t working_promoted = (size_t) policy->avg_promoted()->padded_average();
   120     gclog_or_tty->print_cr(" padded promoted %d K / 0x%x",
   121       working_promoted/K, working_promoted);
   122     gclog_or_tty->print_cr(" used %d K / 0x%x",
   123       used_in_bytes()/K, used_in_bytes());
   124     gclog_or_tty->print_cr(" min_gen_size() %d K / 0x%x",
   125       min_gen_size()/K, min_gen_size());
   126     gclog_or_tty->print_cr(" max_contraction %d K / 0x%x",
   127       max_contraction/K, max_contraction);
   128     gclog_or_tty->print_cr("    without alignment %d K / 0x%x",
   129       policy->promo_increment(max_contraction)/K,
   130       policy->promo_increment(max_contraction));
   131     gclog_or_tty->print_cr(" alignment 0x%x", gen_alignment);
   132   }
   133   assert(result_aligned <= max_contraction, "arithmetic is wrong");
   134   return result_aligned;
   135 }

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