1 /* 2 * Copyright (c) 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 */ 24 25 #include "precompiled.hpp" 26 #include "gc_implementation/g1/g1PageBasedVirtualSpace.hpp" 27 #include "oops/markOop.hpp" 28 #include "oops/oop.inline.hpp" 29 #include "services/memTracker.hpp" 30 #ifdef TARGET_OS_FAMILY_linux 31 # include "os_linux.inline.hpp" 32 #endif 33 #ifdef TARGET_OS_FAMILY_solaris 34 # include "os_solaris.inline.hpp" 35 #endif 36 #ifdef TARGET_OS_FAMILY_windows 37 # include "os_windows.inline.hpp" 38 #endif 39 #ifdef TARGET_OS_FAMILY_aix 40 # include "os_aix.inline.hpp" 41 #endif 42 #ifdef TARGET_OS_FAMILY_bsd 43 # include "os_bsd.inline.hpp" 44 #endif 45 #include "utilities/bitMap.inline.hpp" 46 #include "utilities/copy.hpp" 47 48 G1PageBasedVirtualSpace::G1PageBasedVirtualSpace() : _low_boundary(NULL), 49 _high_boundary(NULL), _committed(), _page_size(0), _special(false), 50 _needs_clear_on_commit(), _executable(false) { 51 } 52 53 bool G1PageBasedVirtualSpace::initialize_with_granularity(ReservedSpace rs, size_t page_size) { 54 if (!rs.is_reserved()) { 55 return false; // Allocation failed. 56 } 57 assert(_low_boundary == NULL, "VirtualSpace already initialized"); 58 assert(page_size > 0, "Granularity must be non-zero."); 59 60 _low_boundary = rs.base(); 61 _high_boundary = _low_boundary + rs.size(); 62 63 _special = rs.special(); 64 _executable = rs.executable(); 65 66 _page_size = page_size; 67 68 assert(_committed.size() == 0, "virtual space initialized more than once"); 69 uintx size_in_bits = rs.size() / page_size; 70 _committed.resize(size_in_bits, /* in_resource_area */ false); 71 if (_special) { 72 _needs_clear_on_commit.resize(size_in_bits, /* in_resource_area */ false); 73 } 74 75 return true; 76 } 77 78 79 G1PageBasedVirtualSpace::~G1PageBasedVirtualSpace() { 80 release(); 81 } 82 83 void G1PageBasedVirtualSpace::release() { 84 // This does not release memory it never reserved. 85 // Caller must release via rs.release(); 86 _low_boundary = NULL; 87 _high_boundary = NULL; 88 _special = false; 89 _executable = false; 90 _page_size = 0; 91 _committed.resize(0, false); 92 _needs_clear_on_commit.resize(0, false); 93 } 94 95 size_t G1PageBasedVirtualSpace::committed_size() const { 96 return _committed.count_one_bits() * _page_size; 97 } 98 99 size_t G1PageBasedVirtualSpace::reserved_size() const { 100 return pointer_delta(_high_boundary, _low_boundary, sizeof(char)); 101 } 102 103 size_t G1PageBasedVirtualSpace::uncommitted_size() const { 104 return reserved_size() - committed_size(); 105 } 106 107 uintptr_t G1PageBasedVirtualSpace::addr_to_page_index(char* addr) const { 108 return (addr - _low_boundary) / _page_size; 109 } 110 111 bool G1PageBasedVirtualSpace::is_area_committed(uintptr_t start, size_t size_in_pages) const { 112 uintptr_t end = start + size_in_pages; 113 return _committed.get_next_zero_offset(start, end) >= end; 114 } 115 116 bool G1PageBasedVirtualSpace::is_area_uncommitted(uintptr_t start, size_t size_in_pages) const { 117 uintptr_t end = start + size_in_pages; 118 return _committed.get_next_one_offset(start, end) >= end; 119 } 120 121 char* G1PageBasedVirtualSpace::page_start(uintptr_t index) { 122 return _low_boundary + index * _page_size; 123 } 124 125 size_t G1PageBasedVirtualSpace::byte_size_for_pages(size_t num) { 126 return num * _page_size; 127 } 128 129 MemRegion G1PageBasedVirtualSpace::commit(uintptr_t start, size_t size_in_pages) { 130 // We need to make sure to commit all pages covered by the given area. 131 guarantee(is_area_uncommitted(start, size_in_pages), "Specified area is not uncommitted"); 132 133 if (_special) { 134 // When the memory is _special it is not really uncommitted. _needs_clear_on_commit 135 // is used to communicate that the memory needs to be cleared because it is seen by 136 // others as uncommitted. 137 for (uintptr_t page_index = start; page_index < start + size_in_pages; page_index++) { 138 if (_needs_clear_on_commit.at(page_index)) { 139 Copy::zero_to_bytes((HeapWord*)page_start(page_index), _page_size); 140 _needs_clear_on_commit.clear_bit(page_index); 141 } 142 } 143 } else { 144 os::commit_memory_or_exit(page_start(start), byte_size_for_pages(size_in_pages), _executable, 145 err_msg("Failed to commit pages from "SIZE_FORMAT" of length "SIZE_FORMAT, start, size_in_pages)); 146 } 147 _committed.set_range(start, start + size_in_pages); 148 149 MemRegion result((HeapWord*)page_start(start), byte_size_for_pages(size_in_pages) / HeapWordSize); 150 if (AlwaysPreTouch) { 151 os::pretouch_memory((char*)result.start(), (char*)result.end()); 152 } 153 return result; 154 } 155 156 MemRegion G1PageBasedVirtualSpace::uncommit(uintptr_t start, size_t size_in_pages) { 157 guarantee(is_area_committed(start, size_in_pages), "checking"); 158 159 if (_special) { 160 // Mark that memory needs to be cleared if committed again. 161 _needs_clear_on_commit.set_range(start, start + size_in_pages); 162 } else { 163 os::uncommit_memory(page_start(start), byte_size_for_pages(size_in_pages)); 164 } 165 166 _committed.clear_range(start, start + size_in_pages); 167 168 MemRegion result((HeapWord*)page_start(start), byte_size_for_pages(size_in_pages) / HeapWordSize); 169 return result; 170 } 171 172 bool G1PageBasedVirtualSpace::contains(const void* p) const { 173 return _low_boundary <= (const char*) p && (const char*) p < _high_boundary; 174 } 175 176 #ifndef PRODUCT 177 void G1PageBasedVirtualSpace::print_on(outputStream* out) { 178 out->print ("Virtual space:"); 179 if (special()) out->print(" (pinned in memory)"); 180 out->cr(); 181 out->print_cr(" - committed: " SIZE_FORMAT, committed_size()); 182 out->print_cr(" - reserved: " SIZE_FORMAT, reserved_size()); 183 out->print_cr(" - [low_b, high_b]: [" INTPTR_FORMAT ", " INTPTR_FORMAT "]", p2i(_low_boundary), p2i(_high_boundary)); 184 } 185 186 void G1PageBasedVirtualSpace::print() { 187 print_on(tty); 188 } 189 #endif