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