1 /*
2 * Copyright (c) 1997, 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 "logging/log.hpp"
27 #include "memory/resourceArea.hpp"
28 #include "memory/virtualspace.hpp"
29 #include "oops/markOop.hpp"
30 #include "oops/oop.inline.hpp"
31 #include "services/memTracker.hpp"
32 #include "utilities/align.hpp"
33
34 // ReservedSpace
35
36 // Dummy constructor
37 ReservedSpace::ReservedSpace() : _base(NULL), _size(0), _noaccess_prefix(0),
38 _alignment(0), _special(false), _executable(false) {
39 }
40
41 ReservedSpace::ReservedSpace(size_t size, size_t preferred_page_size) {
42 bool has_preferred_page_size = preferred_page_size != 0;
43 // Want to use large pages where possible and pad with small pages.
44 size_t page_size = has_preferred_page_size ? preferred_page_size : os::page_size_for_region_unaligned(size, 1);
45 bool large_pages = page_size != (size_t)os::vm_page_size();
46 size_t alignment;
47 if (large_pages && has_preferred_page_size) {
48 alignment = MAX2(page_size, (size_t)os::vm_allocation_granularity());
49 // ReservedSpace initialization requires size to be aligned to the given
50 // alignment. Align the size up.
51 size = align_up(size, alignment);
52 } else {
53 // Don't force the alignment to be large page aligned,
54 // since that will waste memory.
55 alignment = os::vm_allocation_granularity();
56 }
57 initialize(size, alignment, large_pages, NULL, false);
58 }
59
60 ReservedSpace::ReservedSpace(size_t size, size_t alignment,
61 bool large,
62 char* requested_address) {
63 initialize(size, alignment, large, requested_address, false);
64 }
65
66 ReservedSpace::ReservedSpace(size_t size, size_t alignment,
67 bool large,
68 bool executable) {
69 initialize(size, alignment, large, NULL, executable);
70 }
71
72 // Helper method.
73 static bool failed_to_reserve_as_requested(char* base, char* requested_address,
74 const size_t size, bool special)
75 {
76 if (base == requested_address || requested_address == NULL)
77 return false; // did not fail
78
79 if (base != NULL) {
80 // Different reserve address may be acceptable in other cases
81 // but for compressed oops heap should be at requested address.
82 assert(UseCompressedOops, "currently requested address used only for compressed oops");
83 log_debug(gc, heap, coops)("Reserved memory not at requested address: " PTR_FORMAT " vs " PTR_FORMAT, p2i(base), p2i(requested_address));
84 // OS ignored requested address. Try different address.
85 if (special) {
86 if (!os::release_memory_special(base, size)) {
87 fatal("os::release_memory_special failed");
88 }
89 } else {
90 if (!os::release_memory(base, size)) {
91 fatal("os::release_memory failed");
92 }
93 }
94 }
95 return true;
96 }
97
98 void ReservedSpace::initialize(size_t size, size_t alignment, bool large,
99 char* requested_address,
100 bool executable) {
101 const size_t granularity = os::vm_allocation_granularity();
102 assert((size & (granularity - 1)) == 0,
103 "size not aligned to os::vm_allocation_granularity()");
104 assert((alignment & (granularity - 1)) == 0,
105 "alignment not aligned to os::vm_allocation_granularity()");
106 assert(alignment == 0 || is_power_of_2((intptr_t)alignment),
107 "not a power of 2");
108
109 alignment = MAX2(alignment, (size_t)os::vm_page_size());
110
111 _base = NULL;
112 _size = 0;
113 _special = false;
114 _executable = executable;
115 _alignment = 0;
116 _noaccess_prefix = 0;
117 if (size == 0) {
118 return;
119 }
120
121 // If OS doesn't support demand paging for large page memory, we need
122 // to use reserve_memory_special() to reserve and pin the entire region.
123 bool special = large && !os::can_commit_large_page_memory();
124 char* base = NULL;
125
126 if (special) {
127
128 base = os::reserve_memory_special(size, alignment, requested_address, executable);
129
130 if (base != NULL) {
131 if (failed_to_reserve_as_requested(base, requested_address, size, true)) {
132 // OS ignored requested address. Try different address.
133 return;
134 }
135 // Check alignment constraints.
136 assert((uintptr_t) base % alignment == 0,
137 "Large pages returned a non-aligned address, base: "
138 PTR_FORMAT " alignment: " SIZE_FORMAT_HEX,
139 p2i(base), alignment);
140 _special = true;
141 } else {
142 // failed; try to reserve regular memory below
143 if (UseLargePages && (!FLAG_IS_DEFAULT(UseLargePages) ||
144 !FLAG_IS_DEFAULT(LargePageSizeInBytes))) {
145 log_debug(gc, heap, coops)("Reserve regular memory without large pages");
146 }
147 }
148 }
149
150 if (base == NULL) {
151 // Optimistically assume that the OSes returns an aligned base pointer.
152 // When reserving a large address range, most OSes seem to align to at
153 // least 64K.
154
155 // If the memory was requested at a particular address, use
156 // os::attempt_reserve_memory_at() to avoid over mapping something
157 // important. If available space is not detected, return NULL.
158
159 if (requested_address != 0) {
160 base = os::attempt_reserve_memory_at(size, requested_address);
161 if (failed_to_reserve_as_requested(base, requested_address, size, false)) {
162 // OS ignored requested address. Try different address.
163 base = NULL;
164 }
165 } else {
166 base = os::reserve_memory(size, NULL, alignment);
167 }
168
169 if (base == NULL) return;
170
171 // Check alignment constraints
172 if ((((size_t)base) & (alignment - 1)) != 0) {
173 // Base not aligned, retry
174 if (!os::release_memory(base, size)) fatal("os::release_memory failed");
175 // Make sure that size is aligned
176 size = align_up(size, alignment);
177 base = os::reserve_memory_aligned(size, alignment);
178
179 if (requested_address != 0 &&
180 failed_to_reserve_as_requested(base, requested_address, size, false)) {
181 // As a result of the alignment constraints, the allocated base differs
182 // from the requested address. Return back to the caller who can
183 // take remedial action (like try again without a requested address).
184 assert(_base == NULL, "should be");
185 return;
186 }
187 }
188 }
189 // Done
190 _base = base;
191 _size = size;
192 _alignment = alignment;
193 }
194
195
196 ReservedSpace::ReservedSpace(char* base, size_t size, size_t alignment,
197 bool special, bool executable) {
198 assert((size % os::vm_allocation_granularity()) == 0,
199 "size not allocation aligned");
200 _base = base;
201 _size = size;
202 _alignment = alignment;
203 _noaccess_prefix = 0;
204 _special = special;
205 _executable = executable;
206 }
207
208
209 ReservedSpace ReservedSpace::first_part(size_t partition_size, size_t alignment,
210 bool split, bool realloc) {
211 assert(partition_size <= size(), "partition failed");
212 if (split) {
213 os::split_reserved_memory(base(), size(), partition_size, realloc);
214 }
215 ReservedSpace result(base(), partition_size, alignment, special(),
216 executable());
217 return result;
218 }
219
220
221 ReservedSpace
222 ReservedSpace::last_part(size_t partition_size, size_t alignment) {
223 assert(partition_size <= size(), "partition failed");
224 ReservedSpace result(base() + partition_size, size() - partition_size,
225 alignment, special(), executable());
226 return result;
227 }
228
229
230 size_t ReservedSpace::page_align_size_up(size_t size) {
231 return align_up(size, os::vm_page_size());
232 }
233
234
235 size_t ReservedSpace::page_align_size_down(size_t size) {
236 return align_down(size, os::vm_page_size());
237 }
238
239
240 size_t ReservedSpace::allocation_align_size_up(size_t size) {
241 return align_up(size, os::vm_allocation_granularity());
242 }
243
244
245 size_t ReservedSpace::allocation_align_size_down(size_t size) {
246 return align_down(size, os::vm_allocation_granularity());
247 }
248
249
250 void ReservedSpace::release() {
251 if (is_reserved()) {
252 char *real_base = _base - _noaccess_prefix;
253 const size_t real_size = _size + _noaccess_prefix;
254 if (special()) {
255 os::release_memory_special(real_base, real_size);
256 } else{
257 os::release_memory(real_base, real_size);
258 }
259 _base = NULL;
260 _size = 0;
261 _noaccess_prefix = 0;
262 _alignment = 0;
263 _special = false;
264 _executable = false;
265 }
266 }
267
268 static size_t noaccess_prefix_size(size_t alignment) {
269 return lcm(os::vm_page_size(), alignment);
270 }
271
272 void ReservedHeapSpace::establish_noaccess_prefix() {
273 assert(_alignment >= (size_t)os::vm_page_size(), "must be at least page size big");
274 _noaccess_prefix = noaccess_prefix_size(_alignment);
275
276 if (base() && base() + _size > (char *)OopEncodingHeapMax) {
277 if (true
278 WIN64_ONLY(&& !UseLargePages)
279 AIX_ONLY(&& os::vm_page_size() != 64*K)) {
280 // Protect memory at the base of the allocated region.
281 // If special, the page was committed (only matters on windows)
282 if (!os::protect_memory(_base, _noaccess_prefix, os::MEM_PROT_NONE, _special)) {
283 fatal("cannot protect protection page");
284 }
285 log_debug(gc, heap, coops)("Protected page at the reserved heap base: "
286 PTR_FORMAT " / " INTX_FORMAT " bytes",
287 p2i(_base),
288 _noaccess_prefix);
289 assert(Universe::narrow_oop_use_implicit_null_checks() == true, "not initialized?");
290 } else {
291 Universe::set_narrow_oop_use_implicit_null_checks(false);
292 }
293 }
294
295 _base += _noaccess_prefix;
296 _size -= _noaccess_prefix;
297 assert(((uintptr_t)_base % _alignment == 0), "must be exactly of required alignment");
298 }
299
300 // Tries to allocate memory of size 'size' at address requested_address with alignment 'alignment'.
301 // Does not check whether the reserved memory actually is at requested_address, as the memory returned
302 // might still fulfill the wishes of the caller.
303 // Assures the memory is aligned to 'alignment'.
304 // NOTE: If ReservedHeapSpace already points to some reserved memory this is freed, first.
305 void ReservedHeapSpace::try_reserve_heap(size_t size,
306 size_t alignment,
307 bool large,
308 char* requested_address) {
309 if (_base != NULL) {
310 // We tried before, but we didn't like the address delivered.
311 release();
312 }
313
314 // If OS doesn't support demand paging for large page memory, we need
315 // to use reserve_memory_special() to reserve and pin the entire region.
316 bool special = large && !os::can_commit_large_page_memory();
317 char* base = NULL;
318
319 log_trace(gc, heap, coops)("Trying to allocate at address " PTR_FORMAT
320 " heap of size " SIZE_FORMAT_HEX,
321 p2i(requested_address),
322 size);
323
324 if (special) {
325 base = os::reserve_memory_special(size, alignment, requested_address, false);
326
327 if (base != NULL) {
328 // Check alignment constraints.
329 assert((uintptr_t) base % alignment == 0,
330 "Large pages returned a non-aligned address, base: "
331 PTR_FORMAT " alignment: " SIZE_FORMAT_HEX,
332 p2i(base), alignment);
333 _special = true;
334 }
335 }
336
337 if (base == NULL) {
338 // Failed; try to reserve regular memory below
339 if (UseLargePages && (!FLAG_IS_DEFAULT(UseLargePages) ||
340 !FLAG_IS_DEFAULT(LargePageSizeInBytes))) {
341 log_debug(gc, heap, coops)("Reserve regular memory without large pages");
342 }
343
344 // Optimistically assume that the OSes returns an aligned base pointer.
345 // When reserving a large address range, most OSes seem to align to at
346 // least 64K.
347
348 // If the memory was requested at a particular address, use
349 // os::attempt_reserve_memory_at() to avoid over mapping something
350 // important. If available space is not detected, return NULL.
351
352 if (requested_address != 0) {
353 base = os::attempt_reserve_memory_at(size, requested_address);
354 } else {
355 base = os::reserve_memory(size, NULL, alignment);
356 }
357 }
358 if (base == NULL) { return; }
359
360 // Done
361 _base = base;
362 _size = size;
363 _alignment = alignment;
364
365 // Check alignment constraints
366 if ((((size_t)base) & (alignment - 1)) != 0) {
367 // Base not aligned, retry.
368 release();
369 }
370 }
371
372 void ReservedHeapSpace::try_reserve_range(char *highest_start,
373 char *lowest_start,
374 size_t attach_point_alignment,
375 char *aligned_heap_base_min_address,
376 char *upper_bound,
377 size_t size,
378 size_t alignment,
379 bool large) {
380 const size_t attach_range = highest_start - lowest_start;
381 // Cap num_attempts at possible number.
382 // At least one is possible even for 0 sized attach range.
383 const uint64_t num_attempts_possible = (attach_range / attach_point_alignment) + 1;
384 const uint64_t num_attempts_to_try = MIN2((uint64_t)HeapSearchSteps, num_attempts_possible);
385
386 const size_t stepsize = (attach_range == 0) ? // Only one try.
387 (size_t) highest_start : align_up(attach_range / num_attempts_to_try, attach_point_alignment);
388
389 // Try attach points from top to bottom.
390 char* attach_point = highest_start;
391 while (attach_point >= lowest_start &&
392 attach_point <= highest_start && // Avoid wrap around.
393 ((_base == NULL) ||
394 (_base < aligned_heap_base_min_address || _base + size > upper_bound))) {
395 try_reserve_heap(size, alignment, large, attach_point);
396 attach_point -= stepsize;
397 }
398 }
399
400 #define SIZE_64K ((uint64_t) UCONST64( 0x10000))
401 #define SIZE_256M ((uint64_t) UCONST64( 0x10000000))
402 #define SIZE_32G ((uint64_t) UCONST64( 0x800000000))
403
404 // Helper for heap allocation. Returns an array with addresses
405 // (OS-specific) which are suited for disjoint base mode. Array is
406 // NULL terminated.
407 static char** get_attach_addresses_for_disjoint_mode() {
408 static uint64_t addresses[] = {
409 2 * SIZE_32G,
410 3 * SIZE_32G,
411 4 * SIZE_32G,
412 8 * SIZE_32G,
413 10 * SIZE_32G,
414 1 * SIZE_64K * SIZE_32G,
415 2 * SIZE_64K * SIZE_32G,
416 3 * SIZE_64K * SIZE_32G,
417 4 * SIZE_64K * SIZE_32G,
418 16 * SIZE_64K * SIZE_32G,
419 32 * SIZE_64K * SIZE_32G,
420 34 * SIZE_64K * SIZE_32G,
421 0
422 };
423
424 // Sort out addresses smaller than HeapBaseMinAddress. This assumes
425 // the array is sorted.
426 uint i = 0;
427 while (addresses[i] != 0 &&
428 (addresses[i] < OopEncodingHeapMax || addresses[i] < HeapBaseMinAddress)) {
429 i++;
430 }
431 uint start = i;
432
433 // Avoid more steps than requested.
434 i = 0;
435 while (addresses[start+i] != 0) {
436 if (i == HeapSearchSteps) {
437 addresses[start+i] = 0;
438 break;
439 }
440 i++;
441 }
442
443 return (char**) &addresses[start];
444 }
445
446 void ReservedHeapSpace::initialize_compressed_heap(const size_t size, size_t alignment, bool large) {
447 guarantee(size + noaccess_prefix_size(alignment) <= OopEncodingHeapMax,
448 "can not allocate compressed oop heap for this size");
449 guarantee(alignment == MAX2(alignment, (size_t)os::vm_page_size()), "alignment too small");
450 assert(HeapBaseMinAddress > 0, "sanity");
451
452 const size_t granularity = os::vm_allocation_granularity();
453 assert((size & (granularity - 1)) == 0,
454 "size not aligned to os::vm_allocation_granularity()");
455 assert((alignment & (granularity - 1)) == 0,
456 "alignment not aligned to os::vm_allocation_granularity()");
457 assert(alignment == 0 || is_power_of_2((intptr_t)alignment),
458 "not a power of 2");
459
460 // The necessary attach point alignment for generated wish addresses.
461 // This is needed to increase the chance of attaching for mmap and shmat.
462 const size_t os_attach_point_alignment =
463 AIX_ONLY(SIZE_256M) // Known shm boundary alignment.
464 NOT_AIX(os::vm_allocation_granularity());
465 const size_t attach_point_alignment = lcm(alignment, os_attach_point_alignment);
466
467 char *aligned_heap_base_min_address = (char *)align_up((void *)HeapBaseMinAddress, alignment);
468 size_t noaccess_prefix = ((aligned_heap_base_min_address + size) > (char*)OopEncodingHeapMax) ?
469 noaccess_prefix_size(alignment) : 0;
470
471 // Attempt to alloc at user-given address.
472 if (!FLAG_IS_DEFAULT(HeapBaseMinAddress)) {
473 try_reserve_heap(size + noaccess_prefix, alignment, large, aligned_heap_base_min_address);
474 if (_base != aligned_heap_base_min_address) { // Enforce this exact address.
475 release();
476 }
477 }
478
479 // Keep heap at HeapBaseMinAddress.
480 if (_base == NULL) {
481
482 // Try to allocate the heap at addresses that allow efficient oop compression.
483 // Different schemes are tried, in order of decreasing optimization potential.
484 //
485 // For this, try_reserve_heap() is called with the desired heap base addresses.
486 // A call into the os layer to allocate at a given address can return memory
487 // at a different address than requested. Still, this might be memory at a useful
488 // address. try_reserve_heap() always returns this allocated memory, as only here
489 // the criteria for a good heap are checked.
490
491 // Attempt to allocate so that we can run without base and scale (32-Bit unscaled compressed oops).
492 // Give it several tries from top of range to bottom.
493 if (aligned_heap_base_min_address + size <= (char *)UnscaledOopHeapMax) {
494
495 // Calc address range within we try to attach (range of possible start addresses).
496 char* const highest_start = align_down((char *)UnscaledOopHeapMax - size, attach_point_alignment);
497 char* const lowest_start = align_up(aligned_heap_base_min_address, attach_point_alignment);
498 try_reserve_range(highest_start, lowest_start, attach_point_alignment,
499 aligned_heap_base_min_address, (char *)UnscaledOopHeapMax, size, alignment, large);
500 }
501
502 // zerobased: Attempt to allocate in the lower 32G.
503 // But leave room for the compressed class pointers, which is allocated above
504 // the heap.
505 char *zerobased_max = (char *)OopEncodingHeapMax;
506 const size_t class_space = align_up(CompressedClassSpaceSize, alignment);
507 // For small heaps, save some space for compressed class pointer
508 // space so it can be decoded with no base.
509 if (UseCompressedClassPointers && !UseSharedSpaces &&
510 OopEncodingHeapMax <= KlassEncodingMetaspaceMax &&
511 (uint64_t)(aligned_heap_base_min_address + size + class_space) <= KlassEncodingMetaspaceMax) {
512 zerobased_max = (char *)OopEncodingHeapMax - class_space;
513 }
514
515 // Give it several tries from top of range to bottom.
516 if (aligned_heap_base_min_address + size <= zerobased_max && // Zerobased theoretical possible.
517 ((_base == NULL) || // No previous try succeeded.
518 (_base + size > zerobased_max))) { // Unscaled delivered an arbitrary address.
519
520 // Calc address range within we try to attach (range of possible start addresses).
521 char *const highest_start = align_down(zerobased_max - size, attach_point_alignment);
522 // Need to be careful about size being guaranteed to be less
523 // than UnscaledOopHeapMax due to type constraints.
524 char *lowest_start = aligned_heap_base_min_address;
525 uint64_t unscaled_end = UnscaledOopHeapMax - size;
526 if (unscaled_end < UnscaledOopHeapMax) { // unscaled_end wrapped if size is large
527 lowest_start = MAX2(lowest_start, (char*)unscaled_end);
528 }
529 lowest_start = align_up(lowest_start, attach_point_alignment);
530 try_reserve_range(highest_start, lowest_start, attach_point_alignment,
531 aligned_heap_base_min_address, zerobased_max, size, alignment, large);
532 }
533
534 // Now we go for heaps with base != 0. We need a noaccess prefix to efficiently
535 // implement null checks.
536 noaccess_prefix = noaccess_prefix_size(alignment);
537
538 // Try to attach at addresses that are aligned to OopEncodingHeapMax. Disjointbase mode.
539 char** addresses = get_attach_addresses_for_disjoint_mode();
540 int i = 0;
541 while (addresses[i] && // End of array not yet reached.
542 ((_base == NULL) || // No previous try succeeded.
543 (_base + size > (char *)OopEncodingHeapMax && // Not zerobased or unscaled address.
544 !Universe::is_disjoint_heap_base_address((address)_base)))) { // Not disjoint address.
545 char* const attach_point = addresses[i];
546 assert(attach_point >= aligned_heap_base_min_address, "Flag support broken");
547 try_reserve_heap(size + noaccess_prefix, alignment, large, attach_point);
548 i++;
549 }
550
551 // Last, desperate try without any placement.
552 if (_base == NULL) {
553 log_trace(gc, heap, coops)("Trying to allocate at address NULL heap of size " SIZE_FORMAT_HEX, size + noaccess_prefix);
554 initialize(size + noaccess_prefix, alignment, large, NULL, false);
555 }
556 }
557 }
558
559 ReservedHeapSpace::ReservedHeapSpace(size_t size, size_t alignment, bool large) : ReservedSpace() {
560
561 if (size == 0) {
562 return;
563 }
564
565 // Heap size should be aligned to alignment, too.
566 guarantee(is_aligned(size, alignment), "set by caller");
567
568 if (UseCompressedOops) {
569 initialize_compressed_heap(size, alignment, large);
570 if (_size > size) {
571 // We allocated heap with noaccess prefix.
572 // It can happen we get a zerobased/unscaled heap with noaccess prefix,
573 // if we had to try at arbitrary address.
574 establish_noaccess_prefix();
575 }
576 } else {
577 initialize(size, alignment, large, NULL, false);
578 }
579
580 assert(markOopDesc::encode_pointer_as_mark(_base)->decode_pointer() == _base,
581 "area must be distinguishable from marks for mark-sweep");
582 assert(markOopDesc::encode_pointer_as_mark(&_base[size])->decode_pointer() == &_base[size],
583 "area must be distinguishable from marks for mark-sweep");
584
585 if (base() != NULL) {
586 MemTracker::record_virtual_memory_type((address)base(), mtJavaHeap);
587 }
588 }
589
590 // Reserve space for code segment. Same as Java heap only we mark this as
591 // executable.
592 ReservedCodeSpace::ReservedCodeSpace(size_t r_size,
593 size_t rs_align,
594 bool large) :
595 ReservedSpace(r_size, rs_align, large, /*executable*/ true) {
596 MemTracker::record_virtual_memory_type((address)base(), mtCode);
597 }
598
599 // VirtualSpace
600
601 VirtualSpace::VirtualSpace() {
602 _low_boundary = NULL;
603 _high_boundary = NULL;
604 _low = NULL;
605 _high = NULL;
606 _lower_high = NULL;
607 _middle_high = NULL;
608 _upper_high = NULL;
609 _lower_high_boundary = NULL;
610 _middle_high_boundary = NULL;
611 _upper_high_boundary = NULL;
612 _lower_alignment = 0;
613 _middle_alignment = 0;
614 _upper_alignment = 0;
615 _special = false;
616 _executable = false;
617 }
618
619
620 bool VirtualSpace::initialize(ReservedSpace rs, size_t committed_size) {
621 const size_t max_commit_granularity = os::page_size_for_region_unaligned(rs.size(), 1);
622 return initialize_with_granularity(rs, committed_size, max_commit_granularity);
623 }
624
625 bool VirtualSpace::initialize_with_granularity(ReservedSpace rs, size_t committed_size, size_t max_commit_granularity) {
626 if(!rs.is_reserved()) return false; // allocation failed.
627 assert(_low_boundary == NULL, "VirtualSpace already initialized");
628 assert(max_commit_granularity > 0, "Granularity must be non-zero.");
629
630 _low_boundary = rs.base();
631 _high_boundary = low_boundary() + rs.size();
632
633 _low = low_boundary();
634 _high = low();
635
636 _special = rs.special();
637 _executable = rs.executable();
638
639 // When a VirtualSpace begins life at a large size, make all future expansion
640 // and shrinking occur aligned to a granularity of large pages. This avoids
641 // fragmentation of physical addresses that inhibits the use of large pages
642 // by the OS virtual memory system. Empirically, we see that with a 4MB
643 // page size, the only spaces that get handled this way are codecache and
644 // the heap itself, both of which provide a substantial performance
645 // boost in many benchmarks when covered by large pages.
646 //
647 // No attempt is made to force large page alignment at the very top and
648 // bottom of the space if they are not aligned so already.
649 _lower_alignment = os::vm_page_size();
650 _middle_alignment = max_commit_granularity;
651 _upper_alignment = os::vm_page_size();
652
653 // End of each region
654 _lower_high_boundary = align_up(low_boundary(), middle_alignment());
655 _middle_high_boundary = align_down(high_boundary(), middle_alignment());
656 _upper_high_boundary = high_boundary();
657
658 // High address of each region
659 _lower_high = low_boundary();
660 _middle_high = lower_high_boundary();
661 _upper_high = middle_high_boundary();
662
663 // commit to initial size
664 if (committed_size > 0) {
665 if (!expand_by(committed_size)) {
666 return false;
667 }
668 }
669 return true;
670 }
671
672
673 VirtualSpace::~VirtualSpace() {
674 release();
675 }
676
677
678 void VirtualSpace::release() {
679 // This does not release memory it reserved.
680 // Caller must release via rs.release();
681 _low_boundary = NULL;
682 _high_boundary = NULL;
683 _low = NULL;
684 _high = NULL;
685 _lower_high = NULL;
686 _middle_high = NULL;
687 _upper_high = NULL;
688 _lower_high_boundary = NULL;
689 _middle_high_boundary = NULL;
690 _upper_high_boundary = NULL;
691 _lower_alignment = 0;
692 _middle_alignment = 0;
693 _upper_alignment = 0;
694 _special = false;
695 _executable = false;
696 }
697
698
699 size_t VirtualSpace::committed_size() const {
700 return pointer_delta(high(), low(), sizeof(char));
701 }
702
703
704 size_t VirtualSpace::reserved_size() const {
705 return pointer_delta(high_boundary(), low_boundary(), sizeof(char));
706 }
707
708
709 size_t VirtualSpace::uncommitted_size() const {
710 return reserved_size() - committed_size();
711 }
712
713 size_t VirtualSpace::actual_committed_size() const {
714 // Special VirtualSpaces commit all reserved space up front.
715 if (special()) {
716 return reserved_size();
717 }
718
719 size_t committed_low = pointer_delta(_lower_high, _low_boundary, sizeof(char));
720 size_t committed_middle = pointer_delta(_middle_high, _lower_high_boundary, sizeof(char));
721 size_t committed_high = pointer_delta(_upper_high, _middle_high_boundary, sizeof(char));
722
723 #ifdef ASSERT
724 size_t lower = pointer_delta(_lower_high_boundary, _low_boundary, sizeof(char));
725 size_t middle = pointer_delta(_middle_high_boundary, _lower_high_boundary, sizeof(char));
726 size_t upper = pointer_delta(_upper_high_boundary, _middle_high_boundary, sizeof(char));
727
728 if (committed_high > 0) {
729 assert(committed_low == lower, "Must be");
730 assert(committed_middle == middle, "Must be");
731 }
732
733 if (committed_middle > 0) {
734 assert(committed_low == lower, "Must be");
735 }
736 if (committed_middle < middle) {
737 assert(committed_high == 0, "Must be");
738 }
739
740 if (committed_low < lower) {
741 assert(committed_high == 0, "Must be");
742 assert(committed_middle == 0, "Must be");
743 }
744 #endif
745
746 return committed_low + committed_middle + committed_high;
747 }
748
749
750 bool VirtualSpace::contains(const void* p) const {
751 return low() <= (const char*) p && (const char*) p < high();
752 }
753
754 static void pretouch_expanded_memory(void* start, void* end) {
755 assert(is_aligned(start, os::vm_page_size()), "Unexpected alignment");
756 assert(is_aligned(end, os::vm_page_size()), "Unexpected alignment");
757
758 os::pretouch_memory(start, end);
759 }
760
761 static bool commit_expanded(char* start, size_t size, size_t alignment, bool pre_touch, bool executable) {
762 if (os::commit_memory(start, size, alignment, executable)) {
763 if (pre_touch || AlwaysPreTouch) {
764 pretouch_expanded_memory(start, start + size);
765 }
766 return true;
767 }
768
769 debug_only(warning(
770 "INFO: os::commit_memory(" PTR_FORMAT ", " PTR_FORMAT
771 " size=" SIZE_FORMAT ", executable=%d) failed",
772 p2i(start), p2i(start + size), size, executable);)
773
774 return false;
775 }
776
777 /*
778 First we need to determine if a particular virtual space is using large
779 pages. This is done at the initialize function and only virtual spaces
780 that are larger than LargePageSizeInBytes use large pages. Once we
781 have determined this, all expand_by and shrink_by calls must grow and
782 shrink by large page size chunks. If a particular request
783 is within the current large page, the call to commit and uncommit memory
784 can be ignored. In the case that the low and high boundaries of this
785 space is not large page aligned, the pages leading to the first large
786 page address and the pages after the last large page address must be
787 allocated with default pages.
788 */
789 bool VirtualSpace::expand_by(size_t bytes, bool pre_touch) {
790 if (uncommitted_size() < bytes) {
791 return false;
792 }
793
794 if (special()) {
795 // don't commit memory if the entire space is pinned in memory
796 _high += bytes;
797 return true;
798 }
799
800 char* previous_high = high();
801 char* unaligned_new_high = high() + bytes;
802 assert(unaligned_new_high <= high_boundary(), "cannot expand by more than upper boundary");
803
804 // Calculate where the new high for each of the regions should be. If
805 // the low_boundary() and high_boundary() are LargePageSizeInBytes aligned
806 // then the unaligned lower and upper new highs would be the
807 // lower_high() and upper_high() respectively.
808 char* unaligned_lower_new_high = MIN2(unaligned_new_high, lower_high_boundary());
809 char* unaligned_middle_new_high = MIN2(unaligned_new_high, middle_high_boundary());
810 char* unaligned_upper_new_high = MIN2(unaligned_new_high, upper_high_boundary());
811
812 // Align the new highs based on the regions alignment. lower and upper
813 // alignment will always be default page size. middle alignment will be
814 // LargePageSizeInBytes if the actual size of the virtual space is in
815 // fact larger than LargePageSizeInBytes.
816 char* aligned_lower_new_high = align_up(unaligned_lower_new_high, lower_alignment());
817 char* aligned_middle_new_high = align_up(unaligned_middle_new_high, middle_alignment());
818 char* aligned_upper_new_high = align_up(unaligned_upper_new_high, upper_alignment());
819
820 // Determine which regions need to grow in this expand_by call.
821 // If you are growing in the lower region, high() must be in that
822 // region so calculate the size based on high(). For the middle and
823 // upper regions, determine the starting point of growth based on the
824 // location of high(). By getting the MAX of the region's low address
825 // (or the previous region's high address) and high(), we can tell if it
826 // is an intra or inter region growth.
827 size_t lower_needs = 0;
828 if (aligned_lower_new_high > lower_high()) {
829 lower_needs = pointer_delta(aligned_lower_new_high, lower_high(), sizeof(char));
830 }
831 size_t middle_needs = 0;
832 if (aligned_middle_new_high > middle_high()) {
833 middle_needs = pointer_delta(aligned_middle_new_high, middle_high(), sizeof(char));
834 }
835 size_t upper_needs = 0;
836 if (aligned_upper_new_high > upper_high()) {
837 upper_needs = pointer_delta(aligned_upper_new_high, upper_high(), sizeof(char));
838 }
839
840 // Check contiguity.
841 assert(low_boundary() <= lower_high() && lower_high() <= lower_high_boundary(),
842 "high address must be contained within the region");
843 assert(lower_high_boundary() <= middle_high() && middle_high() <= middle_high_boundary(),
844 "high address must be contained within the region");
845 assert(middle_high_boundary() <= upper_high() && upper_high() <= upper_high_boundary(),
846 "high address must be contained within the region");
847
848 // Commit regions
849 if (lower_needs > 0) {
850 assert(lower_high() + lower_needs <= lower_high_boundary(), "must not expand beyond region");
851 if (!commit_expanded(lower_high(), lower_needs, _lower_alignment, pre_touch, _executable)) {
852 return false;
853 }
854 _lower_high += lower_needs;
855 }
856
857 if (middle_needs > 0) {
858 assert(middle_high() + middle_needs <= middle_high_boundary(), "must not expand beyond region");
859 if (!commit_expanded(middle_high(), middle_needs, _middle_alignment, pre_touch, _executable)) {
860 return false;
861 }
862 _middle_high += middle_needs;
863 }
864
865 if (upper_needs > 0) {
866 assert(upper_high() + upper_needs <= upper_high_boundary(), "must not expand beyond region");
867 if (!commit_expanded(upper_high(), upper_needs, _upper_alignment, pre_touch, _executable)) {
868 return false;
869 }
870 _upper_high += upper_needs;
871 }
872
873 _high += bytes;
874 return true;
875 }
876
877 // A page is uncommitted if the contents of the entire page is deemed unusable.
878 // Continue to decrement the high() pointer until it reaches a page boundary
879 // in which case that particular page can now be uncommitted.
880 void VirtualSpace::shrink_by(size_t size) {
881 if (committed_size() < size)
882 fatal("Cannot shrink virtual space to negative size");
883
884 if (special()) {
885 // don't uncommit if the entire space is pinned in memory
886 _high -= size;
887 return;
888 }
889
890 char* unaligned_new_high = high() - size;
891 assert(unaligned_new_high >= low_boundary(), "cannot shrink past lower boundary");
892
893 // Calculate new unaligned address
894 char* unaligned_upper_new_high =
895 MAX2(unaligned_new_high, middle_high_boundary());
896 char* unaligned_middle_new_high =
897 MAX2(unaligned_new_high, lower_high_boundary());
898 char* unaligned_lower_new_high =
899 MAX2(unaligned_new_high, low_boundary());
900
901 // Align address to region's alignment
902 char* aligned_upper_new_high = align_up(unaligned_upper_new_high, upper_alignment());
903 char* aligned_middle_new_high = align_up(unaligned_middle_new_high, middle_alignment());
904 char* aligned_lower_new_high = align_up(unaligned_lower_new_high, lower_alignment());
905
906 // Determine which regions need to shrink
907 size_t upper_needs = 0;
908 if (aligned_upper_new_high < upper_high()) {
909 upper_needs =
910 pointer_delta(upper_high(), aligned_upper_new_high, sizeof(char));
911 }
912 size_t middle_needs = 0;
913 if (aligned_middle_new_high < middle_high()) {
914 middle_needs =
915 pointer_delta(middle_high(), aligned_middle_new_high, sizeof(char));
916 }
917 size_t lower_needs = 0;
918 if (aligned_lower_new_high < lower_high()) {
919 lower_needs =
920 pointer_delta(lower_high(), aligned_lower_new_high, sizeof(char));
921 }
922
923 // Check contiguity.
924 assert(middle_high_boundary() <= upper_high() &&
925 upper_high() <= upper_high_boundary(),
926 "high address must be contained within the region");
927 assert(lower_high_boundary() <= middle_high() &&
928 middle_high() <= middle_high_boundary(),
929 "high address must be contained within the region");
930 assert(low_boundary() <= lower_high() &&
931 lower_high() <= lower_high_boundary(),
932 "high address must be contained within the region");
933
934 // Uncommit
935 if (upper_needs > 0) {
936 assert(middle_high_boundary() <= aligned_upper_new_high &&
937 aligned_upper_new_high + upper_needs <= upper_high_boundary(),
938 "must not shrink beyond region");
939 if (!os::uncommit_memory(aligned_upper_new_high, upper_needs)) {
940 debug_only(warning("os::uncommit_memory failed"));
941 return;
942 } else {
943 _upper_high -= upper_needs;
944 }
945 }
946 if (middle_needs > 0) {
947 assert(lower_high_boundary() <= aligned_middle_new_high &&
948 aligned_middle_new_high + middle_needs <= middle_high_boundary(),
949 "must not shrink beyond region");
950 if (!os::uncommit_memory(aligned_middle_new_high, middle_needs)) {
951 debug_only(warning("os::uncommit_memory failed"));
952 return;
953 } else {
954 _middle_high -= middle_needs;
955 }
956 }
957 if (lower_needs > 0) {
958 assert(low_boundary() <= aligned_lower_new_high &&
959 aligned_lower_new_high + lower_needs <= lower_high_boundary(),
960 "must not shrink beyond region");
961 if (!os::uncommit_memory(aligned_lower_new_high, lower_needs)) {
962 debug_only(warning("os::uncommit_memory failed"));
963 return;
964 } else {
965 _lower_high -= lower_needs;
966 }
967 }
968
969 _high -= size;
970 }
971
972 #ifndef PRODUCT
973 void VirtualSpace::check_for_contiguity() {
974 // Check contiguity.
975 assert(low_boundary() <= lower_high() &&
976 lower_high() <= lower_high_boundary(),
977 "high address must be contained within the region");
978 assert(lower_high_boundary() <= middle_high() &&
979 middle_high() <= middle_high_boundary(),
980 "high address must be contained within the region");
981 assert(middle_high_boundary() <= upper_high() &&
982 upper_high() <= upper_high_boundary(),
983 "high address must be contained within the region");
984 assert(low() >= low_boundary(), "low");
985 assert(low_boundary() <= lower_high_boundary(), "lower high boundary");
986 assert(upper_high_boundary() <= high_boundary(), "upper high boundary");
987 assert(high() <= upper_high(), "upper high");
988 }
989
990 void VirtualSpace::print_on(outputStream* out) {
991 out->print ("Virtual space:");
992 if (special()) out->print(" (pinned in memory)");
993 out->cr();
994 out->print_cr(" - committed: " SIZE_FORMAT, committed_size());
995 out->print_cr(" - reserved: " SIZE_FORMAT, reserved_size());
996 out->print_cr(" - [low, high]: [" INTPTR_FORMAT ", " INTPTR_FORMAT "]", p2i(low()), p2i(high()));
997 out->print_cr(" - [low_b, high_b]: [" INTPTR_FORMAT ", " INTPTR_FORMAT "]", p2i(low_boundary()), p2i(high_boundary()));
998 }
999
1000 void VirtualSpace::print() {
1001 print_on(tty);
1002 }
1003
1004 /////////////// Unit tests ///////////////
1005
1006 #ifndef PRODUCT
1007
1008 #define test_log(...) \
1009 do {\
1010 if (VerboseInternalVMTests) { \
1011 tty->print_cr(__VA_ARGS__); \
1012 tty->flush(); \
1013 }\
1014 } while (false)
1015
1016 class TestReservedSpace : AllStatic {
1017 public:
1018 static void small_page_write(void* addr, size_t size) {
1019 size_t page_size = os::vm_page_size();
1020
1021 char* end = (char*)addr + size;
1022 for (char* p = (char*)addr; p < end; p += page_size) {
1023 *p = 1;
1024 }
1025 }
1026
1027 static void release_memory_for_test(ReservedSpace rs) {
1028 if (rs.special()) {
1029 guarantee(os::release_memory_special(rs.base(), rs.size()), "Shouldn't fail");
1030 } else {
1031 guarantee(os::release_memory(rs.base(), rs.size()), "Shouldn't fail");
1032 }
1033 }
1034
1035 static void test_reserved_space1(size_t size, size_t alignment) {
1036 test_log("test_reserved_space1(%p)", (void*) (uintptr_t) size);
1037
1038 assert(is_aligned(size, alignment), "Incorrect input parameters");
1039
1040 ReservedSpace rs(size, // size
1041 alignment, // alignment
1042 UseLargePages, // large
1043 (char *)NULL); // requested_address
1044
1045 test_log(" rs.special() == %d", rs.special());
1046
1047 assert(rs.base() != NULL, "Must be");
1048 assert(rs.size() == size, "Must be");
1049
1050 assert(is_aligned(rs.base(), alignment), "aligned sizes should always give aligned addresses");
1051 assert(is_aligned(rs.size(), alignment), "aligned sizes should always give aligned addresses");
1052
1053 if (rs.special()) {
1054 small_page_write(rs.base(), size);
1055 }
1056
1057 release_memory_for_test(rs);
1058 }
1059
1060 static void test_reserved_space2(size_t size) {
1061 test_log("test_reserved_space2(%p)", (void*)(uintptr_t)size);
1062
1063 assert(is_aligned(size, os::vm_allocation_granularity()), "Must be at least AG aligned");
1064
1065 ReservedSpace rs(size);
1066
1067 test_log(" rs.special() == %d", rs.special());
1068
1069 assert(rs.base() != NULL, "Must be");
1070 assert(rs.size() == size, "Must be");
1071
1072 if (rs.special()) {
1073 small_page_write(rs.base(), size);
1074 }
1075
1076 release_memory_for_test(rs);
1077 }
1078
1079 static void test_reserved_space3(size_t size, size_t alignment, bool maybe_large) {
1080 test_log("test_reserved_space3(%p, %p, %d)",
1081 (void*)(uintptr_t)size, (void*)(uintptr_t)alignment, maybe_large);
1082
1083 if (size < alignment) {
1084 // Tests might set -XX:LargePageSizeInBytes=<small pages> and cause unexpected input arguments for this test.
1085 assert((size_t)os::vm_page_size() == os::large_page_size(), "Test needs further refinement");
1086 return;
1087 }
1088
1089 assert(is_aligned(size, os::vm_allocation_granularity()), "Must be at least AG aligned");
1090 assert(is_aligned(size, alignment), "Must be at least aligned against alignment");
1091
1092 bool large = maybe_large && UseLargePages && size >= os::large_page_size();
1093
1094 ReservedSpace rs(size, alignment, large, false);
1095
1096 test_log(" rs.special() == %d", rs.special());
1097
1098 assert(rs.base() != NULL, "Must be");
1099 assert(rs.size() == size, "Must be");
1100
1101 if (rs.special()) {
1102 small_page_write(rs.base(), size);
1103 }
1104
1105 release_memory_for_test(rs);
1106 }
1107
1108
1109 static void test_reserved_space1() {
1110 size_t size = 2 * 1024 * 1024;
1111 size_t ag = os::vm_allocation_granularity();
1112
1113 test_reserved_space1(size, ag);
1114 test_reserved_space1(size * 2, ag);
1115 test_reserved_space1(size * 10, ag);
1116 }
1117
1118 static void test_reserved_space2() {
1119 size_t size = 2 * 1024 * 1024;
1120 size_t ag = os::vm_allocation_granularity();
1121
1122 test_reserved_space2(size * 1);
1123 test_reserved_space2(size * 2);
1124 test_reserved_space2(size * 10);
1125 test_reserved_space2(ag);
1126 test_reserved_space2(size - ag);
1127 test_reserved_space2(size);
1128 test_reserved_space2(size + ag);
1129 test_reserved_space2(size * 2);
1130 test_reserved_space2(size * 2 - ag);
1131 test_reserved_space2(size * 2 + ag);
1132 test_reserved_space2(size * 3);
1133 test_reserved_space2(size * 3 - ag);
1134 test_reserved_space2(size * 3 + ag);
1135 test_reserved_space2(size * 10);
1136 test_reserved_space2(size * 10 + size / 2);
1137 }
1138
1139 static void test_reserved_space3() {
1140 size_t ag = os::vm_allocation_granularity();
1141
1142 test_reserved_space3(ag, ag , false);
1143 test_reserved_space3(ag * 2, ag , false);
1144 test_reserved_space3(ag * 3, ag , false);
1145 test_reserved_space3(ag * 2, ag * 2, false);
1146 test_reserved_space3(ag * 4, ag * 2, false);
1147 test_reserved_space3(ag * 8, ag * 2, false);
1148 test_reserved_space3(ag * 4, ag * 4, false);
1149 test_reserved_space3(ag * 8, ag * 4, false);
1150 test_reserved_space3(ag * 16, ag * 4, false);
1151
1152 if (UseLargePages) {
1153 size_t lp = os::large_page_size();
1154
1155 // Without large pages
1156 test_reserved_space3(lp, ag * 4, false);
1157 test_reserved_space3(lp * 2, ag * 4, false);
1158 test_reserved_space3(lp * 4, ag * 4, false);
1159 test_reserved_space3(lp, lp , false);
1160 test_reserved_space3(lp * 2, lp , false);
1161 test_reserved_space3(lp * 3, lp , false);
1162 test_reserved_space3(lp * 2, lp * 2, false);
1163 test_reserved_space3(lp * 4, lp * 2, false);
1164 test_reserved_space3(lp * 8, lp * 2, false);
1165
1166 // With large pages
1167 test_reserved_space3(lp, ag * 4 , true);
1168 test_reserved_space3(lp * 2, ag * 4, true);
1169 test_reserved_space3(lp * 4, ag * 4, true);
1170 test_reserved_space3(lp, lp , true);
1171 test_reserved_space3(lp * 2, lp , true);
1172 test_reserved_space3(lp * 3, lp , true);
1173 test_reserved_space3(lp * 2, lp * 2, true);
1174 test_reserved_space3(lp * 4, lp * 2, true);
1175 test_reserved_space3(lp * 8, lp * 2, true);
1176 }
1177 }
1178
1179 static void test_reserved_space() {
1180 test_reserved_space1();
1181 test_reserved_space2();
1182 test_reserved_space3();
1183 }
1184 };
1185
1186 void TestReservedSpace_test() {
1187 TestReservedSpace::test_reserved_space();
1188 }
1189
1190 #define assert_equals(actual, expected) \
1191 assert(actual == expected, \
1192 "Got " SIZE_FORMAT " expected " \
1193 SIZE_FORMAT, actual, expected);
1194
1195 #define assert_ge(value1, value2) \
1196 assert(value1 >= value2, \
1197 "'" #value1 "': " SIZE_FORMAT " '" \
1198 #value2 "': " SIZE_FORMAT, value1, value2);
1199
1200 #define assert_lt(value1, value2) \
1201 assert(value1 < value2, \
1202 "'" #value1 "': " SIZE_FORMAT " '" \
1203 #value2 "': " SIZE_FORMAT, value1, value2);
1204
1205
1206 class TestVirtualSpace : AllStatic {
1207 enum TestLargePages {
1208 Default,
1209 Disable,
1210 Reserve,
1211 Commit
1212 };
1213
1214 static ReservedSpace reserve_memory(size_t reserve_size_aligned, TestLargePages mode) {
1215 switch(mode) {
1216 default:
1217 case Default:
1218 case Reserve:
1219 return ReservedSpace(reserve_size_aligned);
1220 case Disable:
1221 case Commit:
1222 return ReservedSpace(reserve_size_aligned,
1223 os::vm_allocation_granularity(),
1224 /* large */ false, /* exec */ false);
1225 }
1226 }
1227
1228 static bool initialize_virtual_space(VirtualSpace& vs, ReservedSpace rs, TestLargePages mode) {
1229 switch(mode) {
1230 default:
1231 case Default:
1232 case Reserve:
1233 return vs.initialize(rs, 0);
1234 case Disable:
1235 return vs.initialize_with_granularity(rs, 0, os::vm_page_size());
1236 case Commit:
1237 return vs.initialize_with_granularity(rs, 0, os::page_size_for_region_unaligned(rs.size(), 1));
1238 }
1239 }
1240
1241 public:
1242 static void test_virtual_space_actual_committed_space(size_t reserve_size, size_t commit_size,
1243 TestLargePages mode = Default) {
1244 size_t granularity = os::vm_allocation_granularity();
1245 size_t reserve_size_aligned = align_up(reserve_size, granularity);
1246
1247 ReservedSpace reserved = reserve_memory(reserve_size_aligned, mode);
1248
1249 assert(reserved.is_reserved(), "Must be");
1250
1251 VirtualSpace vs;
1252 bool initialized = initialize_virtual_space(vs, reserved, mode);
1253 assert(initialized, "Failed to initialize VirtualSpace");
1254
1255 vs.expand_by(commit_size, false);
1256
1257 if (vs.special()) {
1258 assert_equals(vs.actual_committed_size(), reserve_size_aligned);
1259 } else {
1260 assert_ge(vs.actual_committed_size(), commit_size);
1261 // Approximate the commit granularity.
1262 // Make sure that we don't commit using large pages
1263 // if large pages has been disabled for this VirtualSpace.
1264 size_t commit_granularity = (mode == Disable || !UseLargePages) ?
1265 os::vm_page_size() : os::large_page_size();
1266 assert_lt(vs.actual_committed_size(), commit_size + commit_granularity);
1267 }
1268
1269 reserved.release();
1270 }
1271
1272 static void test_virtual_space_actual_committed_space_one_large_page() {
1273 if (!UseLargePages) {
1274 return;
1275 }
1276
1277 size_t large_page_size = os::large_page_size();
1278
1279 ReservedSpace reserved(large_page_size, large_page_size, true, false);
1280
1281 assert(reserved.is_reserved(), "Must be");
1282
1283 VirtualSpace vs;
1284 bool initialized = vs.initialize(reserved, 0);
1285 assert(initialized, "Failed to initialize VirtualSpace");
1286
1287 vs.expand_by(large_page_size, false);
1288
1289 assert_equals(vs.actual_committed_size(), large_page_size);
1290
1291 reserved.release();
1292 }
1293
1294 static void test_virtual_space_actual_committed_space() {
1295 test_virtual_space_actual_committed_space(4 * K, 0);
1296 test_virtual_space_actual_committed_space(4 * K, 4 * K);
1297 test_virtual_space_actual_committed_space(8 * K, 0);
1298 test_virtual_space_actual_committed_space(8 * K, 4 * K);
1299 test_virtual_space_actual_committed_space(8 * K, 8 * K);
1300 test_virtual_space_actual_committed_space(12 * K, 0);
1301 test_virtual_space_actual_committed_space(12 * K, 4 * K);
1302 test_virtual_space_actual_committed_space(12 * K, 8 * K);
1303 test_virtual_space_actual_committed_space(12 * K, 12 * K);
1304 test_virtual_space_actual_committed_space(64 * K, 0);
1305 test_virtual_space_actual_committed_space(64 * K, 32 * K);
1306 test_virtual_space_actual_committed_space(64 * K, 64 * K);
1307 test_virtual_space_actual_committed_space(2 * M, 0);
1308 test_virtual_space_actual_committed_space(2 * M, 4 * K);
1309 test_virtual_space_actual_committed_space(2 * M, 64 * K);
1310 test_virtual_space_actual_committed_space(2 * M, 1 * M);
1311 test_virtual_space_actual_committed_space(2 * M, 2 * M);
1312 test_virtual_space_actual_committed_space(10 * M, 0);
1313 test_virtual_space_actual_committed_space(10 * M, 4 * K);
1314 test_virtual_space_actual_committed_space(10 * M, 8 * K);
1315 test_virtual_space_actual_committed_space(10 * M, 1 * M);
1316 test_virtual_space_actual_committed_space(10 * M, 2 * M);
1317 test_virtual_space_actual_committed_space(10 * M, 5 * M);
1318 test_virtual_space_actual_committed_space(10 * M, 10 * M);
1319 }
1320
1321 static void test_virtual_space_disable_large_pages() {
1322 if (!UseLargePages) {
1323 return;
1324 }
1325 // These test cases verify that if we force VirtualSpace to disable large pages
1326 test_virtual_space_actual_committed_space(10 * M, 0, Disable);
1327 test_virtual_space_actual_committed_space(10 * M, 4 * K, Disable);
1328 test_virtual_space_actual_committed_space(10 * M, 8 * K, Disable);
1329 test_virtual_space_actual_committed_space(10 * M, 1 * M, Disable);
1330 test_virtual_space_actual_committed_space(10 * M, 2 * M, Disable);
1331 test_virtual_space_actual_committed_space(10 * M, 5 * M, Disable);
1332 test_virtual_space_actual_committed_space(10 * M, 10 * M, Disable);
1333
1334 test_virtual_space_actual_committed_space(10 * M, 0, Reserve);
1335 test_virtual_space_actual_committed_space(10 * M, 4 * K, Reserve);
1336 test_virtual_space_actual_committed_space(10 * M, 8 * K, Reserve);
1337 test_virtual_space_actual_committed_space(10 * M, 1 * M, Reserve);
1338 test_virtual_space_actual_committed_space(10 * M, 2 * M, Reserve);
1339 test_virtual_space_actual_committed_space(10 * M, 5 * M, Reserve);
1340 test_virtual_space_actual_committed_space(10 * M, 10 * M, Reserve);
1341
1342 test_virtual_space_actual_committed_space(10 * M, 0, Commit);
1343 test_virtual_space_actual_committed_space(10 * M, 4 * K, Commit);
1344 test_virtual_space_actual_committed_space(10 * M, 8 * K, Commit);
1345 test_virtual_space_actual_committed_space(10 * M, 1 * M, Commit);
1346 test_virtual_space_actual_committed_space(10 * M, 2 * M, Commit);
1347 test_virtual_space_actual_committed_space(10 * M, 5 * M, Commit);
1348 test_virtual_space_actual_committed_space(10 * M, 10 * M, Commit);
1349 }
1350
1351 static void test_virtual_space() {
1352 test_virtual_space_actual_committed_space();
1353 test_virtual_space_actual_committed_space_one_large_page();
1354 test_virtual_space_disable_large_pages();
1355 }
1356 };
1357
1358 void TestVirtualSpace_test() {
1359 TestVirtualSpace::test_virtual_space();
1360 }
1361
1362 #endif // PRODUCT
1363
1364 #endif