g1PageBasedVirtualSpace.cpp revision 11658:8a5735c11a84
1/* 2 * Copyright (c) 2014, 2016, 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/g1/g1PageBasedVirtualSpace.hpp" 27#include "oops/markOop.hpp" 28#include "oops/oop.inline.hpp" 29#include "runtime/os.inline.hpp" 30#include "services/memTracker.hpp" 31#include "utilities/bitMap.inline.hpp" 32 33G1PageBasedVirtualSpace::G1PageBasedVirtualSpace(ReservedSpace rs, size_t used_size, size_t page_size) : 34 _low_boundary(NULL), _high_boundary(NULL), _committed(), _page_size(0), _special(false), 35 _dirty(), _executable(false) { 36 initialize_with_page_size(rs, used_size, page_size); 37} 38 39void G1PageBasedVirtualSpace::initialize_with_page_size(ReservedSpace rs, size_t used_size, size_t page_size) { 40 guarantee(rs.is_reserved(), "Given reserved space must have been reserved already."); 41 42 vmassert(_low_boundary == NULL, "VirtualSpace already initialized"); 43 vmassert(page_size > 0, "Page size must be non-zero."); 44 45 guarantee(is_ptr_aligned(rs.base(), page_size), 46 "Reserved space base " PTR_FORMAT " is not aligned to requested page size " SIZE_FORMAT, p2i(rs.base()), page_size); 47 guarantee(is_size_aligned(used_size, os::vm_page_size()), 48 "Given used reserved space size needs to be OS page size aligned (%d bytes) but is " SIZE_FORMAT, os::vm_page_size(), used_size); 49 guarantee(used_size <= rs.size(), 50 "Used size of reserved space " SIZE_FORMAT " bytes is smaller than reservation at " SIZE_FORMAT " bytes", used_size, rs.size()); 51 guarantee(is_size_aligned(rs.size(), page_size), 52 "Expected that the virtual space is size aligned, but " SIZE_FORMAT " is not aligned to page size " SIZE_FORMAT, rs.size(), page_size); 53 54 _low_boundary = rs.base(); 55 _high_boundary = _low_boundary + used_size; 56 57 _special = rs.special(); 58 _executable = rs.executable(); 59 60 _page_size = page_size; 61 62 vmassert(_committed.size() == 0, "virtual space initialized more than once"); 63 BitMap::idx_t size_in_pages = rs.size() / page_size; 64 _committed.initialize(size_in_pages); 65 if (_special) { 66 _dirty.initialize(size_in_pages); 67 } 68 69 _tail_size = used_size % _page_size; 70} 71 72G1PageBasedVirtualSpace::~G1PageBasedVirtualSpace() { 73 // This does not release memory it never reserved. 74 // Caller must release via rs.release(); 75 _low_boundary = NULL; 76 _high_boundary = NULL; 77 _special = false; 78 _executable = false; 79 _page_size = 0; 80 _tail_size = 0; 81} 82 83size_t G1PageBasedVirtualSpace::committed_size() const { 84 size_t result = _committed.count_one_bits() * _page_size; 85 // The last page might not be in full. 86 if (is_last_page_partial() && _committed.at(_committed.size() - 1)) { 87 result -= _page_size - _tail_size; 88 } 89 return result; 90} 91 92size_t G1PageBasedVirtualSpace::reserved_size() const { 93 return pointer_delta(_high_boundary, _low_boundary, sizeof(char)); 94} 95 96size_t G1PageBasedVirtualSpace::uncommitted_size() const { 97 return reserved_size() - committed_size(); 98} 99 100size_t G1PageBasedVirtualSpace::addr_to_page_index(char* addr) const { 101 return (addr - _low_boundary) / _page_size; 102} 103 104bool G1PageBasedVirtualSpace::is_area_committed(size_t start_page, size_t size_in_pages) const { 105 size_t end_page = start_page + size_in_pages; 106 return _committed.get_next_zero_offset(start_page, end_page) >= end_page; 107} 108 109bool G1PageBasedVirtualSpace::is_area_uncommitted(size_t start_page, size_t size_in_pages) const { 110 size_t end_page = start_page + size_in_pages; 111 return _committed.get_next_one_offset(start_page, end_page) >= end_page; 112} 113 114char* G1PageBasedVirtualSpace::page_start(size_t index) const { 115 return _low_boundary + index * _page_size; 116} 117 118bool G1PageBasedVirtualSpace::is_after_last_page(size_t index) const { 119 guarantee(index <= _committed.size(), 120 "Given boundary page " SIZE_FORMAT " is beyond managed page count " SIZE_FORMAT, index, _committed.size()); 121 return index == _committed.size(); 122} 123 124void G1PageBasedVirtualSpace::commit_preferred_pages(size_t start, size_t num_pages) { 125 vmassert(num_pages > 0, "No full pages to commit"); 126 vmassert(start + num_pages <= _committed.size(), 127 "Tried to commit area from page " SIZE_FORMAT " to page " SIZE_FORMAT " " 128 "that is outside of managed space of " SIZE_FORMAT " pages", 129 start, start + num_pages, _committed.size()); 130 131 char* start_addr = page_start(start); 132 size_t size = num_pages * _page_size; 133 134 os::commit_memory_or_exit(start_addr, size, _page_size, _executable, 135 err_msg("Failed to commit area from " PTR_FORMAT " to " PTR_FORMAT " of length " SIZE_FORMAT ".", 136 p2i(start_addr), p2i(start_addr + size), size)); 137} 138 139void G1PageBasedVirtualSpace::commit_tail() { 140 vmassert(_tail_size > 0, "The size of the tail area must be > 0 when reaching here"); 141 142 char* const aligned_end_address = (char*)align_ptr_down(_high_boundary, _page_size); 143 os::commit_memory_or_exit(aligned_end_address, _tail_size, os::vm_page_size(), _executable, 144 err_msg("Failed to commit tail area from " PTR_FORMAT " to " PTR_FORMAT " of length " SIZE_FORMAT ".", 145 p2i(aligned_end_address), p2i(_high_boundary), _tail_size)); 146} 147 148void G1PageBasedVirtualSpace::commit_internal(size_t start_page, size_t end_page) { 149 guarantee(start_page < end_page, 150 "Given start page " SIZE_FORMAT " is larger or equal to end page " SIZE_FORMAT, start_page, end_page); 151 guarantee(end_page <= _committed.size(), 152 "Given end page " SIZE_FORMAT " is beyond end of managed page amount of " SIZE_FORMAT, end_page, _committed.size()); 153 154 size_t pages = end_page - start_page; 155 bool need_to_commit_tail = is_after_last_page(end_page) && is_last_page_partial(); 156 157 // If we have to commit some (partial) tail area, decrease the amount of pages to avoid 158 // committing that in the full-page commit code. 159 if (need_to_commit_tail) { 160 pages--; 161 } 162 163 if (pages > 0) { 164 commit_preferred_pages(start_page, pages); 165 } 166 167 if (need_to_commit_tail) { 168 commit_tail(); 169 } 170} 171 172char* G1PageBasedVirtualSpace::bounded_end_addr(size_t end_page) const { 173 return MIN2(_high_boundary, page_start(end_page)); 174} 175 176void G1PageBasedVirtualSpace::pretouch_internal(size_t start_page, size_t end_page) { 177 guarantee(start_page < end_page, 178 "Given start page " SIZE_FORMAT " is larger or equal to end page " SIZE_FORMAT, start_page, end_page); 179 180 os::pretouch_memory(page_start(start_page), bounded_end_addr(end_page)); 181} 182 183bool G1PageBasedVirtualSpace::commit(size_t start_page, size_t size_in_pages) { 184 // We need to make sure to commit all pages covered by the given area. 185 guarantee(is_area_uncommitted(start_page, size_in_pages), "Specified area is not uncommitted"); 186 187 bool zero_filled = true; 188 size_t end_page = start_page + size_in_pages; 189 190 if (_special) { 191 // Check for dirty pages and update zero_filled if any found. 192 if (_dirty.get_next_one_offset(start_page, end_page) < end_page) { 193 zero_filled = false; 194 _dirty.clear_range(start_page, end_page); 195 } 196 } else { 197 commit_internal(start_page, end_page); 198 } 199 _committed.set_range(start_page, end_page); 200 201 if (AlwaysPreTouch) { 202 pretouch_internal(start_page, end_page); 203 } 204 return zero_filled; 205} 206 207void G1PageBasedVirtualSpace::uncommit_internal(size_t start_page, size_t end_page) { 208 guarantee(start_page < end_page, 209 "Given start page " SIZE_FORMAT " is larger or equal to end page " SIZE_FORMAT, start_page, end_page); 210 211 char* start_addr = page_start(start_page); 212 os::uncommit_memory(start_addr, pointer_delta(bounded_end_addr(end_page), start_addr, sizeof(char))); 213} 214 215void G1PageBasedVirtualSpace::uncommit(size_t start_page, size_t size_in_pages) { 216 guarantee(is_area_committed(start_page, size_in_pages), "checking"); 217 218 size_t end_page = start_page + size_in_pages; 219 if (_special) { 220 // Mark that memory is dirty. If committed again the memory might 221 // need to be cleared explicitly. 222 _dirty.set_range(start_page, end_page); 223 } else { 224 uncommit_internal(start_page, end_page); 225 } 226 227 _committed.clear_range(start_page, end_page); 228} 229 230bool G1PageBasedVirtualSpace::contains(const void* p) const { 231 return _low_boundary <= (const char*) p && (const char*) p < _high_boundary; 232} 233 234#ifndef PRODUCT 235void G1PageBasedVirtualSpace::print_on(outputStream* out) { 236 out->print ("Virtual space:"); 237 if (_special) out->print(" (pinned in memory)"); 238 out->cr(); 239 out->print_cr(" - committed: " SIZE_FORMAT, committed_size()); 240 out->print_cr(" - reserved: " SIZE_FORMAT, reserved_size()); 241 out->print_cr(" - preferred page size: " SIZE_FORMAT, _page_size); 242 out->print_cr(" - [low_b, high_b]: [" PTR_FORMAT ", " PTR_FORMAT "]", p2i(_low_boundary), p2i(_high_boundary)); 243} 244 245void G1PageBasedVirtualSpace::print() { 246 print_on(tty); 247} 248#endif 249