1 /*
2 * Copyright (c) 2019, 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 #include "precompiled.hpp"
25 #include "gc/z/zAddress.inline.hpp"
26 #include "gc/z/zGlobals.hpp"
27 #include "gc/z/zLargePages.inline.hpp"
28 #include "gc/z/zPhysicalMemory.inline.hpp"
29 #include "gc/z/zPhysicalMemoryBacking_bsd.hpp"
30 #include "runtime/globals.hpp"
31 #include "runtime/init.hpp"
32 #include "runtime/os.hpp"
33 #include "utilities/align.hpp"
34 #include "utilities/debug.hpp"
35
36 bool ZPhysicalMemoryBacking::is_initialized() const {
37 return _file.is_initialized();
38 }
39
40 void ZPhysicalMemoryBacking::warn_commit_limits(size_t max) const {
41 // Does nothing
42 }
43
44 bool ZPhysicalMemoryBacking::supports_uncommit() {
45 assert(!is_init_completed(), "Invalid state");
46 assert(_file.size() >= ZGranuleSize, "Invalid size");
47
48 // Test if uncommit is supported by uncommitting and then re-committing a granule
49 return commit(uncommit(ZGranuleSize)) == ZGranuleSize;
50 }
51
52 size_t ZPhysicalMemoryBacking::commit(size_t size) {
53 size_t committed = 0;
54
55 // Fill holes in the backing file
56 while (committed < size) {
57 size_t allocated = 0;
58 const size_t remaining = size - committed;
59 const uintptr_t start = _uncommitted.alloc_from_front_at_most(remaining, &allocated);
60 if (start == UINTPTR_MAX) {
61 // No holes to commit
62 break;
63 }
64
65 // Try commit hole
66 const size_t filled = _file.commit(start, allocated);
67 if (filled > 0) {
68 // Successful or partialy successful
69 _committed.free(start, filled);
70 committed += filled;
71 }
72 if (filled < allocated) {
73 // Failed or partialy failed
74 _uncommitted.free(start + filled, allocated - filled);
75 return committed;
76 }
77 }
78
79 // Expand backing file
80 if (committed < size) {
81 const size_t remaining = size - committed;
82 const uintptr_t start = _file.size();
83 const size_t expanded = _file.commit(start, remaining);
84 if (expanded > 0) {
85 // Successful or partialy successful
86 _committed.free(start, expanded);
87 committed += expanded;
88 }
89 }
90
91 return committed;
92 }
93
94 size_t ZPhysicalMemoryBacking::uncommit(size_t size) {
95 size_t uncommitted = 0;
96
97 // Punch holes in backing file
98 while (uncommitted < size) {
99 size_t allocated = 0;
100 const size_t remaining = size - uncommitted;
101 const uintptr_t start = _committed.alloc_from_back_at_most(remaining, &allocated);
102 assert(start != UINTPTR_MAX, "Allocation should never fail");
103
104 // Try punch hole
105 const size_t punched = _file.uncommit(start, allocated);
106 if (punched > 0) {
107 // Successful or partialy successful
108 _uncommitted.free(start, punched);
109 uncommitted += punched;
110 }
111 if (punched < allocated) {
112 // Failed or partialy failed
113 _committed.free(start + punched, allocated - punched);
114 return uncommitted;
115 }
116 }
117
118 return uncommitted;
119 }
120
121 ZPhysicalMemory ZPhysicalMemoryBacking::alloc(size_t size) {
122 assert(is_aligned(size, ZGranuleSize), "Invalid size");
123
124 ZPhysicalMemory pmem;
125
126 // Allocate segments
127 for (size_t allocated = 0; allocated < size; allocated += ZGranuleSize) {
128 const uintptr_t start = _committed.alloc_from_front(ZGranuleSize);
129 assert(start != UINTPTR_MAX, "Allocation should never fail");
130 pmem.add_segment(ZPhysicalMemorySegment(start, ZGranuleSize));
131 }
132
133 return pmem;
134 }
135
136 void ZPhysicalMemoryBacking::free(const ZPhysicalMemory& pmem) {
137 const size_t nsegments = pmem.nsegments();
138
139 // Free segments
140 for (size_t i = 0; i < nsegments; i++) {
141 const ZPhysicalMemorySegment& segment = pmem.segment(i);
142 _committed.free(segment.start(), segment.size());
143 }
144 }
145
146 void ZPhysicalMemoryBacking::pretouch_view(uintptr_t addr, size_t size) const {
147 const size_t page_size = ZLargePages::is_explicit() ? ZGranuleSize : os::vm_page_size();
148 os::pretouch_memory((void*)addr, (void*)(addr + size), page_size);
149 }
150
151 void ZPhysicalMemoryBacking::map_view(const ZPhysicalMemory& pmem, uintptr_t addr) const {
152 const size_t nsegments = pmem.nsegments();
153 size_t size = 0;
154
155 // Map segments
156 for (size_t i = 0; i < nsegments; i++) {
157 const ZPhysicalMemorySegment& segment = pmem.segment(i);
158 const uintptr_t segment_addr = addr + size;
159 _file.map(segment_addr, segment.size(), segment.start());
160 size += segment.size();
161 }
162 }
163
164 void ZPhysicalMemoryBacking::unmap_view(const ZPhysicalMemory& pmem, uintptr_t addr) const {
165 _file.unmap(addr, pmem.size());
166 }
167
168 uintptr_t ZPhysicalMemoryBacking::nmt_address(uintptr_t offset) const {
169 // From an NMT point of view we treat the first heap view (marked0) as committed
170 return ZAddress::marked0(offset);
171 }
172
173 void ZPhysicalMemoryBacking::pretouch(uintptr_t offset, size_t size) const {
174 if (ZVerifyViews) {
175 // Pre-touch good view
176 pretouch_view(ZAddress::good(offset), size);
177 } else {
178 // Pre-touch all views
179 pretouch_view(ZAddress::marked0(offset), size);
180 pretouch_view(ZAddress::marked1(offset), size);
181 pretouch_view(ZAddress::remapped(offset), size);
182 }
183 }
184
185 void ZPhysicalMemoryBacking::map(const ZPhysicalMemory& pmem, uintptr_t offset) const {
186 if (ZVerifyViews) {
187 // Map good view
188 map_view(pmem, ZAddress::good(offset));
189 } else {
190 // Map all views
191 map_view(pmem, ZAddress::marked0(offset));
192 map_view(pmem, ZAddress::marked1(offset));
193 map_view(pmem, ZAddress::remapped(offset));
194 }
195 }
196
197 void ZPhysicalMemoryBacking::unmap(const ZPhysicalMemory& pmem, uintptr_t offset) const {
198 if (ZVerifyViews) {
199 // Unmap good view
200 unmap_view(pmem, ZAddress::good(offset));
201 } else {
202 // Unmap all views
203 unmap_view(pmem, ZAddress::marked0(offset));
204 unmap_view(pmem, ZAddress::marked1(offset));
205 unmap_view(pmem, ZAddress::remapped(offset));
206 }
207 }
208
209 void ZPhysicalMemoryBacking::debug_map(const ZPhysicalMemory& pmem, uintptr_t offset) const {
210 // Map good view
211 assert(ZVerifyViews, "Should be enabled");
212 map_view(pmem, ZAddress::good(offset));
213 }
214
215 void ZPhysicalMemoryBacking::debug_unmap(const ZPhysicalMemory& pmem, uintptr_t offset) const {
216 // Unmap good view
217 assert(ZVerifyViews, "Should be enabled");
218 unmap_view(pmem, ZAddress::good(offset));
219 }