rev 8854 : 8065331: Add trace events for failed allocations
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   1 /*
   2  * Copyright (c) 2005, 2015, 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.
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  23  */
  24 
  25 #include "precompiled.hpp"
  26 #include "classfile/classLoader.hpp"
  27 #include "classfile/javaClasses.hpp"
  28 #include "gc/shared/gcLocker.inline.hpp"
  29 #include "gc/shared/genCollectedHeap.hpp"
  30 #include "gc/shared/vmGCOperations.hpp"
  31 #include "memory/oopFactory.hpp"
  32 #include "oops/instanceKlass.hpp"
  33 #include "oops/instanceRefKlass.hpp"
  34 #include "runtime/handles.inline.hpp"
  35 #include "runtime/init.hpp"
  36 #include "runtime/interfaceSupport.hpp"
  37 #include "utilities/dtrace.hpp"
  38 #include "utilities/macros.hpp"
  39 #include "utilities/preserveException.hpp"
  40 #if INCLUDE_ALL_GCS
  41 #include "gc/g1/g1CollectedHeap.inline.hpp"
  42 #endif // INCLUDE_ALL_GCS
  43 
  44 VM_GC_Operation::~VM_GC_Operation() {
  45   CollectedHeap* ch = Universe::heap();
  46   ch->collector_policy()->set_all_soft_refs_clear(false);
  47 }
  48 
  49 // The same dtrace probe can't be inserted in two different files, so we
  50 // have to call it here, so it's only in one file.  Can't create new probes
  51 // for the other file anymore.   The dtrace probes have to remain stable.
  52 void VM_GC_Operation::notify_gc_begin(bool full) {
  53   HOTSPOT_GC_BEGIN(
  54                    full);
  55   HS_DTRACE_WORKAROUND_TAIL_CALL_BUG();
  56 }
  57 
  58 void VM_GC_Operation::notify_gc_end() {
  59   HOTSPOT_GC_END();
  60   HS_DTRACE_WORKAROUND_TAIL_CALL_BUG();
  61 }
  62 
  63 void VM_GC_Operation::acquire_pending_list_lock() {
  64   // we may enter this with pending exception set
  65   InstanceRefKlass::acquire_pending_list_lock(&_pending_list_basic_lock);
  66 }
  67 
  68 
  69 void VM_GC_Operation::release_and_notify_pending_list_lock() {
  70 
  71   InstanceRefKlass::release_and_notify_pending_list_lock(&_pending_list_basic_lock);
  72 }
  73 
  74 // Allocations may fail in several threads at about the same time,
  75 // resulting in multiple gc requests.  We only want to do one of them.
  76 // In case a GC locker is active and the need for a GC is already signaled,
  77 // we want to skip this GC attempt altogether, without doing a futile
  78 // safepoint operation.
  79 bool VM_GC_Operation::skip_operation() const {
  80   bool skip = (_gc_count_before != Universe::heap()->total_collections());
  81   if (_full && skip) {
  82     skip = (_full_gc_count_before != Universe::heap()->total_full_collections());
  83   }
  84   if (!skip && GC_locker::is_active_and_needs_gc()) {
  85     skip = Universe::heap()->is_maximal_no_gc();
  86     assert(!(skip && (_gc_cause == GCCause::_gc_locker)),
  87            "GC_locker cannot be active when initiating GC");
  88   }
  89   return skip;
  90 }
  91 
  92 bool VM_GC_Operation::doit_prologue() {
  93   assert(Thread::current()->is_Java_thread(), "just checking");
  94   assert(((_gc_cause != GCCause::_no_gc) &&
  95           (_gc_cause != GCCause::_no_cause_specified)), "Illegal GCCause");
  96 
  97   // To be able to handle a GC the VM initialization needs to be completed.
  98   if (!is_init_completed()) {
  99     vm_exit_during_initialization(
 100       err_msg("GC triggered before VM initialization completed. Try increasing "
 101               "NewSize, current value " SIZE_FORMAT "%s.",
 102               byte_size_in_proper_unit(NewSize),
 103               proper_unit_for_byte_size(NewSize)));
 104   }
 105 
 106   acquire_pending_list_lock();
 107   // If the GC count has changed someone beat us to the collection
 108   // Get the Heap_lock after the pending_list_lock.
 109   Heap_lock->lock();
 110 
 111   // Check invocations
 112   if (skip_operation()) {
 113     // skip collection
 114     Heap_lock->unlock();
 115     release_and_notify_pending_list_lock();
 116     _prologue_succeeded = false;
 117   } else {
 118     _prologue_succeeded = true;
 119   }
 120   return _prologue_succeeded;
 121 }
 122 
 123 
 124 void VM_GC_Operation::doit_epilogue() {
 125   assert(Thread::current()->is_Java_thread(), "just checking");
 126   // Release the Heap_lock first.
 127   Heap_lock->unlock();
 128   release_and_notify_pending_list_lock();
 129 }
 130 
 131 bool VM_GC_HeapInspection::skip_operation() const {
 132   return false;
 133 }
 134 
 135 bool VM_GC_HeapInspection::collect() {
 136   if (GC_locker::is_active()) {
 137     return false;
 138   }
 139   Universe::heap()->collect_as_vm_thread(GCCause::_heap_inspection);
 140   return true;
 141 }
 142 
 143 void VM_GC_HeapInspection::doit() {
 144   HandleMark hm;
 145   Universe::heap()->ensure_parsability(false); // must happen, even if collection does
 146                                                // not happen (e.g. due to GC_locker)
 147                                                // or _full_gc being false
 148   if (_full_gc) {
 149     if (!collect()) {
 150       // The collection attempt was skipped because the gc locker is held.
 151       // The following dump may then be a tad misleading to someone expecting
 152       // only live objects to show up in the dump (see CR 6944195). Just issue
 153       // a suitable warning in that case and do not attempt to do a collection.
 154       // The latter is a subtle point, because even a failed attempt
 155       // to GC will, in fact, induce one in the future, which we
 156       // probably want to avoid in this case because the GC that we may
 157       // be about to attempt holds value for us only
 158       // if it happens now and not if it happens in the eventual
 159       // future.
 160       warning("GC locker is held; pre-dump GC was skipped");
 161     }
 162   }
 163   HeapInspection inspect(_csv_format, _print_help, _print_class_stats,
 164                          _columns);
 165   inspect.heap_inspection(_out);
 166 }
 167 
 168 
 169 void VM_GenCollectForAllocation::doit() {
 170   SvcGCMarker sgcm(SvcGCMarker::MINOR);
 171 
 172   GenCollectedHeap* gch = GenCollectedHeap::heap();
 173   GCCauseSetter gccs(gch, _gc_cause);
 174   _result = gch->satisfy_failed_allocation(_word_size, _tlab);
 175   assert(gch->is_in_reserved_or_null(_result), "result not in heap");
 176 
 177   if (_result == NULL && GC_locker::is_active_and_needs_gc()) {
 178     set_gc_locked();
 179   }
 180 }
 181 
 182 void VM_GenCollectFull::doit() {
 183   SvcGCMarker sgcm(SvcGCMarker::FULL);
 184 
 185   GenCollectedHeap* gch = GenCollectedHeap::heap();
 186   GCCauseSetter gccs(gch, _gc_cause);
 187   gch->do_full_collection(gch->must_clear_all_soft_refs(), _max_generation);
 188 }
 189 
 190 VM_CollectForMetadataAllocation::VM_CollectForMetadataAllocation(ClassLoaderData* loader_data,
 191                                                                  size_t size,
 192                                                                  Metaspace::MetadataType mdtype,
 193                                                                  uint gc_count_before,
 194                                                                  uint full_gc_count_before,
 195                                                                  GCCause::Cause gc_cause)
 196     : VM_GC_Operation(gc_count_before, gc_cause, full_gc_count_before, true),
 197       _loader_data(loader_data), _size(size), _mdtype(mdtype), _result(NULL) {
 198   assert(_size != 0, "An allocation should always be requested with this operation.");
 199   AllocTracer::send_allocation_requiring_gc_event(_size * HeapWordSize, GCId::peek());
 200 }
 201 
 202 // Returns true iff concurrent GCs unloads metadata.
 203 bool VM_CollectForMetadataAllocation::initiate_concurrent_GC() {
 204 #if INCLUDE_ALL_GCS
 205   if (UseConcMarkSweepGC && CMSClassUnloadingEnabled) {
 206     MetaspaceGC::set_should_concurrent_collect(true);
 207     return true;
 208   }
 209 
 210   if (UseG1GC && ClassUnloadingWithConcurrentMark) {
 211     G1CollectedHeap* g1h = G1CollectedHeap::heap();
 212     g1h->g1_policy()->collector_state()->set_initiate_conc_mark_if_possible(true);
 213 
 214     GCCauseSetter x(g1h, _gc_cause);
 215 
 216     // At this point we are supposed to start a concurrent cycle. We
 217     // will do so if one is not already in progress.
 218     bool should_start = g1h->g1_policy()->force_initial_mark_if_outside_cycle(_gc_cause);
 219 
 220     if (should_start) {
 221       double pause_target = g1h->g1_policy()->max_pause_time_ms();
 222       g1h->do_collection_pause_at_safepoint(pause_target);
 223     }
 224     return true;
 225   }
 226 #endif
 227 
 228   return false;
 229 }
 230 
 231 static void log_metaspace_alloc_failure_for_concurrent_GC() {
 232   if (Verbose && PrintGCDetails) {
 233     if (UseConcMarkSweepGC) {
 234       gclog_or_tty->print_cr("\nCMS full GC for Metaspace");
 235     } else if (UseG1GC) {
 236       gclog_or_tty->print_cr("\nG1 full GC for Metaspace");
 237     }
 238   }
 239 }
 240 
 241 void VM_CollectForMetadataAllocation::doit() {
 242   SvcGCMarker sgcm(SvcGCMarker::FULL);
 243 
 244   CollectedHeap* heap = Universe::heap();
 245   GCCauseSetter gccs(heap, _gc_cause);
 246 
 247   // Check again if the space is available.  Another thread
 248   // may have similarly failed a metadata allocation and induced
 249   // a GC that freed space for the allocation.
 250   if (!MetadataAllocationFailALot) {
 251     _result = _loader_data->metaspace_non_null()->allocate(_size, _mdtype);
 252     if (_result != NULL) {
 253       return;
 254     }
 255   }
 256 
 257   if (initiate_concurrent_GC()) {
 258     // For CMS and G1 expand since the collection is going to be concurrent.
 259     _result = _loader_data->metaspace_non_null()->expand_and_allocate(_size, _mdtype);
 260     if (_result != NULL) {
 261       return;
 262     }
 263 
 264     log_metaspace_alloc_failure_for_concurrent_GC();
 265   }
 266 
 267   // Don't clear the soft refs yet.
 268   heap->collect_as_vm_thread(GCCause::_metadata_GC_threshold);
 269   // After a GC try to allocate without expanding.  Could fail
 270   // and expansion will be tried below.
 271   _result = _loader_data->metaspace_non_null()->allocate(_size, _mdtype);
 272   if (_result != NULL) {
 273     return;
 274   }
 275 
 276   // If still failing, allow the Metaspace to expand.
 277   // See delta_capacity_until_GC() for explanation of the
 278   // amount of the expansion.
 279   // This should work unless there really is no more space
 280   // or a MaxMetaspaceSize has been specified on the command line.
 281   _result = _loader_data->metaspace_non_null()->expand_and_allocate(_size, _mdtype);
 282   if (_result != NULL) {
 283     return;
 284   }
 285 
 286   // If expansion failed, do a last-ditch collection and try allocating
 287   // again.  A last-ditch collection will clear softrefs.  This
 288   // behavior is similar to the last-ditch collection done for perm
 289   // gen when it was full and a collection for failed allocation
 290   // did not free perm gen space.
 291   heap->collect_as_vm_thread(GCCause::_last_ditch_collection);
 292   _result = _loader_data->metaspace_non_null()->allocate(_size, _mdtype);
 293   if (_result != NULL) {
 294     return;
 295   }
 296 
 297   if (Verbose && PrintGCDetails) {
 298     gclog_or_tty->print_cr("\nAfter Metaspace GC failed to allocate size "
 299                            SIZE_FORMAT, _size);
 300   }
 301 
 302   if (GC_locker::is_active_and_needs_gc()) {
 303     set_gc_locked();
 304   }
 305 }
 306 
 307 VM_CollectForAllocation::VM_CollectForAllocation(size_t word_size, uint gc_count_before, GCCause::Cause cause)
 308     : VM_GC_Operation(gc_count_before, cause), _result(NULL), _word_size(word_size) {
 309   // Only report if operation was really caused by an allocation.
 310   if (_word_size != 0) {
 311     AllocTracer::send_allocation_requiring_gc_event(_word_size * HeapWordSize, GCId::peek());
 312   }
 313 }
--- EOF ---