1 /*

     2  * Copyright (c) 2017, 2018, 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 "jfr/recorder/storage/jfrVirtualMemory.hpp"

    27 #include "memory/virtualspace.hpp"

    28 #include "runtime/orderAccess.inline.hpp"

    29 #include "runtime/os.hpp"

    30 #include "services/memTracker.hpp"

    31 #include "utilities/globalDefinitions.hpp"

    32 

    33 /*

    34  * A memory segment represents a virtual memory reservation.

    35  * It provides ways to commit and decommit physical storage

    36  * onto its virtual memory reservation.

    37  */

    38 

    39 class JfrVirtualMemorySegment : public JfrCHeapObj {

    40   friend class JfrVirtualMemoryManager;

    41  private:

    42   JfrVirtualMemorySegment* _next;

    43   char* _top;

    44   ReservedSpace _rs;

    45   VirtualSpace  _virtual_memory;

    46 

    47   // Convenience functions to access the underlying virtual space metadata

    48   const u1* committed_low()  const { return (const u1*)_virtual_memory.low(); }

    49   const u1* committed_high() const { return (const u1*)_virtual_memory.high(); }

    50   const u1* reserved_low() const { return (const u1*)_virtual_memory.low_boundary(); }

    51   const u1* reserved_high() const { return (const u1*)_virtual_memory.high_boundary(); }

    52   size_t reserved_words() const  { return _virtual_memory.reserved_size() / BytesPerWord; }

    53   size_t committed_words() const { return _virtual_memory.actual_committed_size() / BytesPerWord; }

    54   bool is_pre_committed() const { return _virtual_memory.special(); }

    55   VirtualSpace& virtual_space() { return _virtual_memory; }

    56 

    57   JfrVirtualMemorySegment();

    58   ~JfrVirtualMemorySegment();

    59 

    60   JfrVirtualMemorySegment* next() const { return _next; }

    61   void set_next(JfrVirtualMemorySegment* v) { _next = v; }

    62 

    63   // Returns true if requested size is available in the committed area

    64   bool is_available(size_t block_size_request_words) {

    65     return block_size_request_words <= pointer_delta(committed_high(), _top, sizeof(char*));

    66   }

    67 

    68   // allocation pointer committed memory

    69   char* top() const { return _top; }

    70   void inc_top(size_t size_in_words) {

    71     assert(is_available(size_in_words), "invariant");

    72     _top += size_in_words * BytesPerWord;

    73     assert(_top <= _virtual_memory.high(), "invariant");

    74   }

    75 

    76   // initialization is the virtual memory reservation

    77   bool initialize(size_t reservation_size_request_bytes);

    78   void* take_from_committed(size_t block_size_request_words);

    79 

    80   // Returns committed memory

    81   void* commit(size_t block_size_request_words) {

    82     return take_from_committed(block_size_request_words);

    83   }

    84 

    85   // Commit more memory in a reservation

    86   bool expand_by(size_t block_size_request_words);

    87 

    88   // Decommits all committed memory in this reservation segment.

    89   void decommit();

    90 };

    91 

    92 JfrVirtualMemorySegment::JfrVirtualMemorySegment() :

    93   _next(NULL),

    94   _top(NULL),

    95   _rs(),

    96   _virtual_memory() {}

    97 

    98 JfrVirtualMemorySegment::~JfrVirtualMemorySegment() {

    99   decommit();

   100   _rs.release();

   101 }

   102 

   103 bool JfrVirtualMemorySegment::initialize(size_t reservation_size_request_bytes) {

   104   assert(is_aligned(reservation_size_request_bytes, os::vm_allocation_granularity()), "invariant");

   105   _rs = ReservedSpace(reservation_size_request_bytes,

   106                       os::vm_allocation_granularity(),

   107                       UseLargePages && os::can_commit_large_page_memory(),

   108                       false);

   109   if (!_rs.is_reserved()) {

   110     return false;

   111   }

   112   assert(_rs.base() != NULL, "invariant");

   113   assert(_rs.size() != 0, "invariant");

   114   assert(is_aligned(_rs.base(), os::vm_allocation_granularity()), "invariant");

   115   assert(is_aligned(_rs.size(), os::vm_allocation_granularity()), "invariant");

   116   os::trace_page_sizes("Jfr", reservation_size_request_bytes,

   117                               reservation_size_request_bytes,

   118                               os::vm_page_size(),

   119                               _rs.base(),

   120                               _rs.size());

   121   MemTracker::record_virtual_memory_type((address)_rs.base(), mtTracing);

   122   assert(is_aligned(_rs.base(), os::vm_page_size()), "invariant");

   123   assert(is_aligned(_rs.size(), os::vm_page_size()), "invariant");

   124 

   125   // ReservedSpaces marked as special will have the entire memory

   126   // pre-committed. Setting a committed size will make sure that

   127   // committed_size and actual_committed_size agrees.

   128   const size_t pre_committed_size = _rs.special() ? _rs.size() : 0;

   129   const bool result = virtual_space().initialize_with_granularity(_rs, pre_committed_size, os::vm_page_size());

   130 

   131   if (result) {

   132     assert(virtual_space().committed_size() == virtual_space().actual_committed_size(),

   133       "Checking that the pre-committed memory was registered by the VirtualSpace");

   134     _top = virtual_space().low();

   135   }

   136   return result;

   137 }

   138 

   139 bool JfrVirtualMemorySegment::expand_by(size_t block_size_request_words) {

   140   size_t block_size_request_bytes = block_size_request_words * BytesPerWord;

   141   const size_t uncommitted = virtual_space().reserved_size() - virtual_space().actual_committed_size();

   142   if (uncommitted < block_size_request_bytes) {

   143     // commit whatever is left in the reservation

   144     block_size_request_bytes = uncommitted;

   145   }

   146   assert(is_aligned(block_size_request_bytes, os::vm_allocation_granularity()), "invariant");

   147   // commit block in reserved memory

   148   bool result = virtual_space().expand_by(block_size_request_bytes, false);

   149   assert(result, "Failed to commit memory");

   150   return result;

   151 }

   152 

   153 void JfrVirtualMemorySegment::decommit() {

   154   assert(_virtual_memory.committed_size() == _virtual_memory.actual_committed_size(),

   155     "The committed memory doesn't match the expanded memory.");

   156 

   157   const size_t committed_size = virtual_space().actual_committed_size();

   158   if (committed_size > 0) {

   159     virtual_space().shrink_by(committed_size);

   160   }

   161 

   162   assert(_virtual_memory.actual_committed_size() == 0, "invariant");

   163 }

   164 

   165 // Attempt to get a committed block

   166 void* JfrVirtualMemorySegment::take_from_committed(size_t block_size_request_words) {

   167   // The virtual spaces are always expanded by the

   168   // commit granularity to enforce the following condition.

   169   // Without this the is_available check will not work correctly.

   170   assert(_virtual_memory.committed_size() == _virtual_memory.actual_committed_size(),

   171     "The committed memory doesn't match the expanded memory.");

   172   if (!is_available(block_size_request_words)) {

   173     return NULL;

   174   }

   175   void* const block = top();

   176   assert(block != NULL, "invariant");

   177   inc_top(block_size_request_words);

   178   return block;

   179 }

   180 

   181 class JfrVirtualMemoryManager : public JfrCHeapObj {

   182  typedef JfrVirtualMemorySegment Segment;

   183  private:

   184   Segment* _segments;

   185   Segment* _current_segment;

   186   size_t _reservation_size_request_words;

   187   size_t _reservation_size_request_limit_words; // total reservation limit

   188 

   189   // Sum of reserved and committed memory in the segments

   190   size_t _current_reserved_words;

   191   size_t _current_committed_words;

   192 

   193   void link(Segment* segment);

   194   Segment* current();

   195 

   196   void inc_reserved_words(size_t words);

   197   void inc_committed_words(size_t words);

   198 

   199   bool new_segment(size_t reservation_size_request_words);

   200 

   201   bool expand_segment_by(Segment* segment, size_t block_size_request_words);

   202 

   203   bool expand_by(size_t block_size_request_words, size_t reservation_size_request_words);

   204   bool can_reserve() const;

   205 

   206  public:

   207   JfrVirtualMemoryManager();

   208   ~JfrVirtualMemoryManager();

   209 

   210   bool initialize(size_t reservation_size_request_words, size_t segment_count = 1);

   211   void* commit(size_t requested_block_size_words);

   212 

   213   bool is_full() const {

   214     return reserved_high() == committed_high();

   215   }

   216 

   217   const u1* committed_low() const { return _current_segment->committed_low(); }

   218   const u1* committed_high() const { return _current_segment->committed_high(); }

   219   const u1* reserved_low() const { return _current_segment->reserved_low(); }

   220   const u1* reserved_high() const { return _current_segment->reserved_high(); }

   221 };

   222 

   223 JfrVirtualMemoryManager::JfrVirtualMemoryManager() :

   224   _segments(NULL),

   225   _current_segment(NULL),

   226   _reservation_size_request_words(0),

   227   _reservation_size_request_limit_words(0),

   228   _current_reserved_words(0),

   229   _current_committed_words(0) {}

   230 

   231 JfrVirtualMemoryManager::~JfrVirtualMemoryManager() {

   232   JfrVirtualMemorySegment* segment = _segments;

   233   while (segment != NULL) {

   234     JfrVirtualMemorySegment* next_segment = segment->next();

   235     delete segment;

   236     segment = next_segment;

   237   }

   238 }

   239 

   240 // for now only allow a singleton segment per virtual memory client

   241 bool JfrVirtualMemoryManager::initialize(size_t reservation_size_request_words, size_t segment_count /* 1 */) {

   242   assert(is_aligned(reservation_size_request_words * BytesPerWord, os::vm_allocation_granularity()), "invariant");

   243   _reservation_size_request_words = reservation_size_request_words;

   244   assert(segment_count > 0, "invariant");

   245   _reservation_size_request_limit_words = reservation_size_request_words * segment_count;

   246   assert(is_aligned(_reservation_size_request_limit_words * BytesPerWord, os::vm_allocation_granularity()), "invariant");

   247   return new_segment(_reservation_size_request_words);

   248 }

   249 

   250 bool JfrVirtualMemoryManager::can_reserve() const  {

   251   return _reservation_size_request_limit_words == 0 ? true : _current_reserved_words < _reservation_size_request_limit_words;

   252 }

   253 

   254 // Allocate another segment and add it to the list.

   255 bool JfrVirtualMemoryManager::new_segment(size_t reservation_size_request_words) {

   256   assert(reservation_size_request_words > 0, "invariant");

   257   assert(is_aligned(reservation_size_request_words * BytesPerWord, os::vm_allocation_granularity()), "invariant");

   258   Segment* segment = new Segment();

   259   if (NULL == segment) {

   260     return false;

   261   }

   262   if (!segment->initialize(reservation_size_request_words * BytesPerWord)) {

   263     delete segment;

   264     return false;

   265   }

   266   assert(segment->reserved_words() == reservation_size_request_words,

   267     "Actual reserved memory size differs from requested reservation memory size");

   268   link(segment);

   269   return true;

   270 }

   271 

   272 bool JfrVirtualMemoryManager::expand_segment_by(JfrVirtualMemorySegment* segment, size_t block_size_request_words) {

   273   assert(segment != NULL, "invariant");

   274   const size_t before = segment->committed_words();

   275   const bool result = segment->expand_by(block_size_request_words);

   276   const size_t after = segment->committed_words();

   277   // after and before can be the same if the memory was pre-committed.

   278   assert(after >= before, "Inconsistency");

   279   inc_committed_words(after - before);

   280   return result;

   281 }

   282 

   283 void JfrVirtualMemoryManager::inc_reserved_words(size_t words) {

   284   _current_reserved_words += words;

   285 }

   286 

   287 JfrVirtualMemorySegment* JfrVirtualMemoryManager::current() {

   288   return _current_segment;

   289 }

   290 

   291 void JfrVirtualMemoryManager::inc_committed_words(size_t words) {

   292   _current_committed_words += words;

   293 }

   294 

   295 bool JfrVirtualMemoryManager::expand_by(size_t block_size_request_words, size_t reservation_size_request_words) {

   296   assert(is_aligned(block_size_request_words * BytesPerWord, os::vm_page_size()), "invariant");

   297   assert(is_aligned(block_size_request_words * BytesPerWord, os::vm_allocation_granularity()), "invariant");

   298   assert(is_aligned(reservation_size_request_words * BytesPerWord, os::vm_page_size()), "invariant");

   299   assert(is_aligned(reservation_size_request_words * BytesPerWord, os::vm_allocation_granularity()), "invariant");

   300   assert(block_size_request_words <= reservation_size_request_words, "invariant");

   301   // Attempt to commit more memory from the the current virtual space reservation.

   302   if (expand_segment_by(current(), block_size_request_words)) {

   303     return true;

   304   }

   305 

   306   // reached limit of what is allowed to be reserved?

   307   if (!can_reserve()) {

   308     return false;

   309   }

   310 

   311   // Get another segment.

   312   if (!new_segment(reservation_size_request_words)) {

   313     return false;

   314   }

   315 

   316   if (current()->is_pre_committed()) {

   317     // The memory was pre-committed, so we are done here.

   318     assert(block_size_request_words <= current()->committed_words(),

   319            "The new VirtualSpace was pre-committed, so it"

   320            "should be large enough to fit the alloc request.");

   321     return true;

   322   }

   323   return expand_segment_by(current(), block_size_request_words);

   324 }

   325 

   326 void JfrVirtualMemoryManager::link(JfrVirtualMemorySegment* segment) {

   327   assert(segment != NULL, "invariant");

   328   if (_segments == NULL) {

   329     _segments = segment;

   330   } else {

   331     assert(_current_segment != NULL, "invariant");

   332     assert(_segments == _current_segment, "invariant");

   333     _current_segment->set_next(segment);

   334   }

   335   _current_segment = segment;

   336   inc_reserved_words(segment->reserved_words());

   337   inc_committed_words(segment->committed_words());

   338 }

   339 

   340 void* JfrVirtualMemoryManager::commit(size_t block_size_request_words) {

   341   assert(is_aligned(block_size_request_words * BytesPerWord, os::vm_allocation_granularity()), "invariant");

   342   void* block = current()->commit(block_size_request_words);

   343   if (block != NULL) {

   344     return block;

   345   }

   346   assert(block == NULL, "invariant");

   347   if (is_full()) {

   348     return NULL;

   349   }

   350   assert(block_size_request_words <= _reservation_size_request_words, "invariant");

   351   if (expand_by(block_size_request_words, _reservation_size_request_words)) {

   352     block = current()->commit(block_size_request_words);

   353     assert(block != NULL, "The allocation was expected to succeed after the expansion");

   354   }

   355   return block;

   356 }

   357 

   358 JfrVirtualMemory::JfrVirtualMemory() :

   359   _vmm(NULL),

   360   _reserved_low(),

   361   _reserved_high(),

   362   _top(NULL),

   363   _commit_point(NULL),

   364   _physical_commit_size_request_words(0),

   365   _aligned_datum_size_bytes(0) {}

   366 

   367 JfrVirtualMemory::~JfrVirtualMemory() {

   368   assert(_vmm != NULL, "invariant");

   369   delete _vmm;

   370 }

   371 

   372 size_t JfrVirtualMemory::aligned_datum_size_bytes() const {

   373   return _aligned_datum_size_bytes;

   374 }

   375 

   376 static void adjust_allocation_ratio(size_t* const reservation_size_bytes, size_t* const commit_size_bytes) {

   377   assert(reservation_size_bytes != NULL, "invariant");

   378   assert(*reservation_size_bytes > 0, "invariant");

   379   assert(commit_size_bytes != NULL, "invariant");

   380   assert(*commit_size_bytes > 0, "invariant");

   381   assert(*reservation_size_bytes >= *commit_size_bytes, "invariant");

   382   assert(is_aligned(*reservation_size_bytes, os::vm_allocation_granularity()), "invariant");

   383   assert(is_aligned(*commit_size_bytes, os::vm_allocation_granularity()), "invariant");

   384 

   385   size_t reservation_size_units = *reservation_size_bytes / os::vm_allocation_granularity();

   386   size_t commit_size_units = *commit_size_bytes / os::vm_allocation_granularity();

   387   assert(reservation_size_units > 0, "invariant");

   388   assert(commit_size_units > 0, "invariant");

   389 

   390   size_t original_ratio_units = reservation_size_units / commit_size_units;

   391   size_t rem = reservation_size_units % commit_size_units;

   392   assert(original_ratio_units > 0, "invariant");

   393 

   394   if (rem > 0) {

   395     reservation_size_units -= rem % original_ratio_units;

   396     commit_size_units += rem / original_ratio_units;

   397   }

   398 

   399   assert(commit_size_units > 0, "invariant");

   400   assert(reservation_size_units % original_ratio_units == 0, "invariant");

   401   assert(original_ratio_units * commit_size_units == reservation_size_units , "invariant");

   402   assert(original_ratio_units == reservation_size_units / commit_size_units, "invariant");

   403   *reservation_size_bytes = reservation_size_units * os::vm_allocation_granularity();

   404   *commit_size_bytes = commit_size_units * os::vm_allocation_granularity();

   405   assert((*reservation_size_bytes % *commit_size_bytes) == 0, "invariant");

   406 }

   407 

   408 

   409 void* JfrVirtualMemory::initialize(size_t reservation_size_request_bytes,

   410                                    size_t block_size_request_bytes,

   411                                    size_t datum_size_bytes /* 1 */) {

   412   assert(_vmm == NULL, "invariant");

   413   _vmm = new JfrVirtualMemoryManager();

   414 

   415   if (_vmm == NULL) {

   416     return NULL;

   417   }

   418 

   419   assert(reservation_size_request_bytes > 0, "invariant");

   420   _aligned_datum_size_bytes = align_up(datum_size_bytes, BytesPerWord);

   421   assert(is_aligned(_aligned_datum_size_bytes, BytesPerWord), "invariant");

   422 

   423   reservation_size_request_bytes = ReservedSpace::allocation_align_size_up(reservation_size_request_bytes);

   424   assert(is_aligned(reservation_size_request_bytes, os::vm_allocation_granularity()), "invariant");

   425   assert(is_aligned(reservation_size_request_bytes, _aligned_datum_size_bytes), "invariant");

   426   block_size_request_bytes = MAX2(block_size_request_bytes, (size_t)os::vm_allocation_granularity());

   427   block_size_request_bytes = ReservedSpace::allocation_align_size_up(block_size_request_bytes);

   428   assert(is_aligned(block_size_request_bytes, os::vm_allocation_granularity()), "invariant");

   429   assert(is_aligned(block_size_request_bytes, _aligned_datum_size_bytes), "invariant");

   430   // adjustment to valid ratio in units of vm_allocation_granularity

   431   adjust_allocation_ratio(&reservation_size_request_bytes, &block_size_request_bytes);

   432   assert(is_aligned(reservation_size_request_bytes, os::vm_allocation_granularity()), "invariant");

   433   assert(is_aligned(reservation_size_request_bytes, _aligned_datum_size_bytes), "invariant");

   434   assert(is_aligned(block_size_request_bytes, os::vm_allocation_granularity()), "invariant");

   435   assert(is_aligned(block_size_request_bytes, _aligned_datum_size_bytes), "invariant");

   436   assert((reservation_size_request_bytes % block_size_request_bytes) == 0, "invariant");

   437   const size_t reservation_size_request_words = reservation_size_request_bytes / BytesPerWord;

   438   _physical_commit_size_request_words = block_size_request_bytes / BytesPerWord;

   439   // virtual memory reservation

   440   if (!_vmm->initialize(reservation_size_request_words)) {

   441     // is implicitly "full" if reservation fails

   442     assert(is_full(), "invariant");

   443     return NULL;

   444   }

   445   _reserved_low = (const u1*)_vmm->reserved_low();

   446   _reserved_high = (const u1*)_vmm->reserved_high();

   447   // reservation complete

   448   _top = (u1*)_vmm->committed_high();

   449   _commit_point = _top;

   450   assert(_reserved_low == _top, "invariant"); // initial empty state

   451   assert((size_t)(_reserved_high - _reserved_low) == reservation_size_request_bytes, "invariant");

   452   // initial commit

   453   commit_memory_block();

   454   return _top;

   455 }

   456 

   457 void* JfrVirtualMemory::commit(size_t block_size_request_words) {

   458   assert(_vmm != NULL, "invariant");

   459   assert(is_aligned(block_size_request_words * BytesPerWord, os::vm_allocation_granularity()), "invariant");

   460   return _vmm->commit(block_size_request_words);

   461 }

   462 

   463 bool JfrVirtualMemory::is_full() const {

   464   return _top == _reserved_high;

   465 }

   466 

   467 bool JfrVirtualMemory::is_empty() const {

   468   return _top == _reserved_low;

   469 }

   470 

   471 bool JfrVirtualMemory::commit_memory_block() {

   472   assert(_vmm != NULL, "invariant");

   473   assert(!is_full(), "invariant");

   474   assert(_top == _commit_point, "invariant");

   475 

   476   void* const block = _vmm->commit(_physical_commit_size_request_words);

   477   if (block != NULL) {

   478     _commit_point = _vmm->committed_high();

   479     return true;

   480   }

   481   // all reserved virtual memory is committed

   482   assert(block == NULL, "invariant");

   483   assert(_vmm->reserved_high() == _vmm->committed_high(), "invariant");

   484   return false;

   485 }

   486 

   487 void* JfrVirtualMemory::new_datum() {

   488   assert(_vmm != NULL, "invariant");

   489   assert(!is_full(), "invariant");

   490   if (_top == _commit_point) {

   491     if (!commit_memory_block()) {

   492       assert(is_full(), "invariant");

   493       return NULL;

   494     }

   495   }

   496   assert(_top + _aligned_datum_size_bytes <= _commit_point, "invariant");

   497   u1* allocation = _top;

   498   _top += _aligned_datum_size_bytes;

   499   assert(is_aligned(allocation, _aligned_datum_size_bytes), "invariant");

   500   return allocation;

   501 }

   502 

   503 void* JfrVirtualMemory::index_ptr(size_t index) {

   504   assert((index * _aligned_datum_size_bytes) + _reserved_low < _commit_point, "invariant");

   505   return (void*)((index * _aligned_datum_size_bytes) + _reserved_low);

   506 }

   507 

   508 void* JfrVirtualMemory::get(size_t index) {

   509   return index_ptr(index);

   510 }

   511 

   512 size_t JfrVirtualMemory::count() const {

   513   return (_top - _reserved_low) / _aligned_datum_size_bytes;

   514 }

   515 

   516 size_t JfrVirtualMemory::live_set() const {

   517   return _top - _reserved_low;

   518 }

   519 

   520 size_t JfrVirtualMemory::reserved_size() const {

   521   return _reserved_high - _reserved_low;

   522 }

   523 

   524 bool JfrVirtualMemory::compact(size_t index) {

   525   assert(index > 0, "invariant");

   526   assert(index <= reserved_size(), "invariant");

   527   const u1* low = static_cast<u1*>(index_ptr(index));

   528   const size_t block_size = _top - low;

   529   memcpy(const_cast<u1*>(_reserved_low), low, block_size);

   530   _top = const_cast<u1*>(_reserved_low) + block_size;

   531   assert(live_set() == block_size, "invariant");

   532   return true;

   533 }