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 */ 24 25 # include "incls/_precompiled.incl" 26 # include "incls/_asPSOldGen.cpp.incl" 27 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) 51 52 {} 53 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) 62 63 { 64 _virtual_space = vs; 65 } 66 67 void ASPSOldGen::reset_after_change() { 68 _reserved = MemRegion((HeapWord*)virtual_space()->low_boundary(), 69 (HeapWord*)virtual_space()->high_boundary()); 70 post_resize(); 71 } 72 73 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"); 77 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 } 83 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 } 89 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; 105 106 // 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. 110 111 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 }