rev 9681 : 8065331: Add trace events for failed allocations
rev 9682 : imported patch rev

   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.
  22  *
  23  */
  24 
  25 #include "precompiled.hpp"
  26 #include "classfile/classLoader.hpp"
  27 #include "classfile/javaClasses.hpp"
  28 #include "gc/shared/allocTracer.hpp"
  29 #include "gc/shared/gcLocker.inline.hpp"
  30 #include "gc/shared/genCollectedHeap.hpp"
  31 #include "gc/shared/vmGCOperations.hpp"
  32 #include "memory/oopFactory.hpp"
  33 #include "oops/instanceKlass.hpp"
  34 #include "oops/instanceRefKlass.hpp"
  35 #include "runtime/handles.inline.hpp"
  36 #include "runtime/init.hpp"
  37 #include "runtime/interfaceSupport.hpp"
  38 #include "utilities/dtrace.hpp"
  39 #include "utilities/macros.hpp"
  40 #include "utilities/preserveException.hpp"
  41 #if INCLUDE_ALL_GCS
  42 #include "gc/g1/g1CollectedHeap.inline.hpp"
  43 #endif // INCLUDE_ALL_GCS
  44 
  45 VM_GC_Operation::~VM_GC_Operation() {
  46   CollectedHeap* ch = Universe::heap();
  47   ch->collector_policy()->set_all_soft_refs_clear(false);
  48 }
  49 
  50 // The same dtrace probe can't be inserted in two different files, so we
  51 // have to call it here, so it's only in one file.  Can't create new probes
  52 // for the other file anymore.   The dtrace probes have to remain stable.
  53 void VM_GC_Operation::notify_gc_begin(bool full) {
  54   HOTSPOT_GC_BEGIN(
  55                    full);
  56   HS_DTRACE_WORKAROUND_TAIL_CALL_BUG();
  57 }
  58 
  59 void VM_GC_Operation::notify_gc_end() {
  60   HOTSPOT_GC_END();
  61   HS_DTRACE_WORKAROUND_TAIL_CALL_BUG();
  62 }
  63 
  64 void VM_GC_Operation::acquire_pending_list_lock() {
  65   // we may enter this with pending exception set
  66   InstanceRefKlass::acquire_pending_list_lock(&_pending_list_basic_lock);
  67 }
  68 
  69 
  70 void VM_GC_Operation::release_and_notify_pending_list_lock() {
  71 
  72   InstanceRefKlass::release_and_notify_pending_list_lock(&_pending_list_basic_lock);
  73 }
  74 
  75 // Allocations may fail in several threads at about the same time,
  76 // resulting in multiple gc requests.  We only want to do one of them.
  77 // In case a GC locker is active and the need for a GC is already signaled,
  78 // we want to skip this GC attempt altogether, without doing a futile
  79 // safepoint operation.
  80 bool VM_GC_Operation::skip_operation() const {
  81   bool skip = (_gc_count_before != Universe::heap()->total_collections());
  82   if (_full && skip) {
  83     skip = (_full_gc_count_before != Universe::heap()->total_full_collections());
  84   }
  85   if (!skip && GC_locker::is_active_and_needs_gc()) {
  86     skip = Universe::heap()->is_maximal_no_gc();
  87     assert(!(skip && (_gc_cause == GCCause::_gc_locker)),
  88            "GC_locker cannot be active when initiating GC");
  89   }
  90   return skip;
  91 }
  92 
  93 bool VM_GC_Operation::doit_prologue() {
  94   assert(Thread::current()->is_Java_thread(), "just checking");
  95   assert(((_gc_cause != GCCause::_no_gc) &&
  96           (_gc_cause != GCCause::_no_cause_specified)), "Illegal GCCause");
  97 
  98   // To be able to handle a GC the VM initialization needs to be completed.
  99   if (!is_init_completed()) {
 100     vm_exit_during_initialization(
 101       err_msg("GC triggered before VM initialization completed. Try increasing "
 102               "NewSize, current value " SIZE_FORMAT "%s.",
 103               byte_size_in_proper_unit(NewSize),
 104               proper_unit_for_byte_size(NewSize)));
 105   }
 106 
 107   acquire_pending_list_lock();
 108   // If the GC count has changed someone beat us to the collection
 109   // Get the Heap_lock after the pending_list_lock.
 110   Heap_lock->lock();
 111 
 112   // Check invocations
 113   if (skip_operation()) {
 114     // skip collection
 115     Heap_lock->unlock();
 116     release_and_notify_pending_list_lock();
 117     _prologue_succeeded = false;
 118   } else {
 119     _prologue_succeeded = true;
 120   }
 121   return _prologue_succeeded;
 122 }
 123 
 124 
 125 void VM_GC_Operation::doit_epilogue() {
 126   assert(Thread::current()->is_Java_thread(), "just checking");
 127   // Release the Heap_lock first.
 128   Heap_lock->unlock();
 129   release_and_notify_pending_list_lock();
 130 }
 131 
 132 bool VM_GC_HeapInspection::skip_operation() const {
 133   return false;
 134 }
 135 
 136 bool VM_GC_HeapInspection::collect() {
 137   if (GC_locker::is_active()) {
 138     return false;
 139   }
 140   Universe::heap()->collect_as_vm_thread(GCCause::_heap_inspection);
 141   return true;
 142 }
 143 
 144 void VM_GC_HeapInspection::doit() {
 145   HandleMark hm;
 146   Universe::heap()->ensure_parsability(false); // must happen, even if collection does
 147                                                // not happen (e.g. due to GC_locker)
 148                                                // or _full_gc being false
 149   if (_full_gc) {
 150     if (!collect()) {
 151       // The collection attempt was skipped because the gc locker is held.
 152       // The following dump may then be a tad misleading to someone expecting
 153       // only live objects to show up in the dump (see CR 6944195). Just issue
 154       // a suitable warning in that case and do not attempt to do a collection.
 155       // The latter is a subtle point, because even a failed attempt
 156       // to GC will, in fact, induce one in the future, which we
 157       // probably want to avoid in this case because the GC that we may
 158       // be about to attempt holds value for us only
 159       // if it happens now and not if it happens in the eventual
 160       // future.
 161       warning("GC locker is held; pre-dump GC was skipped");
 162     }
 163   }
 164   HeapInspection inspect(_csv_format, _print_help, _print_class_stats,
 165                          _columns);
 166   inspect.heap_inspection(_out);
 167 }
 168 
 169 
 170 void VM_GenCollectForAllocation::doit() {
 171   SvcGCMarker sgcm(SvcGCMarker::MINOR);
 172 
 173   GenCollectedHeap* gch = GenCollectedHeap::heap();
 174   GCCauseSetter gccs(gch, _gc_cause);
 175   _result = gch->satisfy_failed_allocation(_word_size, _tlab);
 176   assert(gch->is_in_reserved_or_null(_result), "result not in heap");
 177 
 178   if (_result == NULL && GC_locker::is_active_and_needs_gc()) {
 179     set_gc_locked();
 180   }
 181 }
 182 
 183 void VM_GenCollectFull::doit() {
 184   SvcGCMarker sgcm(SvcGCMarker::FULL);
 185 
 186   GenCollectedHeap* gch = GenCollectedHeap::heap();
 187   GCCauseSetter gccs(gch, _gc_cause);
 188   gch->do_full_collection(gch->must_clear_all_soft_refs(), _max_generation);
 189 }
 190 
 191 VM_CollectForMetadataAllocation::VM_CollectForMetadataAllocation(ClassLoaderData* loader_data,
 192                                                                  size_t size,
 193                                                                  Metaspace::MetadataType mdtype,
 194                                                                  uint gc_count_before,
 195                                                                  uint full_gc_count_before,
 196                                                                  GCCause::Cause gc_cause)
 197     : VM_GC_Operation(gc_count_before, gc_cause, full_gc_count_before, true),
 198       _loader_data(loader_data), _size(size), _mdtype(mdtype), _result(NULL) {
 199   assert(_size != 0, "An allocation should always be requested with this operation.");
 200   AllocTracer::send_allocation_requiring_gc_event(_size * HeapWordSize);
 201 }
 202 
 203 // Returns true iff concurrent GCs unloads metadata.
 204 bool VM_CollectForMetadataAllocation::initiate_concurrent_GC() {
 205 #if INCLUDE_ALL_GCS
 206   if (UseConcMarkSweepGC && CMSClassUnloadingEnabled) {
 207     MetaspaceGC::set_should_concurrent_collect(true);
 208     return true;
 209   }
 210 
 211   if (UseG1GC && ClassUnloadingWithConcurrentMark) {
 212     G1CollectedHeap* g1h = G1CollectedHeap::heap();
 213     g1h->g1_policy()->collector_state()->set_initiate_conc_mark_if_possible(true);
 214 
 215     GCCauseSetter x(g1h, _gc_cause);
 216 
 217     // At this point we are supposed to start a concurrent cycle. We
 218     // will do so if one is not already in progress.
 219     bool should_start = g1h->g1_policy()->force_initial_mark_if_outside_cycle(_gc_cause);
 220 
 221     if (should_start) {
 222       double pause_target = g1h->g1_policy()->max_pause_time_ms();
 223       g1h->do_collection_pause_at_safepoint(pause_target);
 224     }
 225     return true;
 226   }
 227 #endif
 228 
 229   return false;
 230 }
 231 
 232 static void log_metaspace_alloc_failure_for_concurrent_GC() {
 233   if (Verbose && PrintGCDetails) {
 234     if (UseConcMarkSweepGC) {
 235       gclog_or_tty->print_cr("\nCMS full GC for Metaspace");
 236     } else if (UseG1GC) {
 237       gclog_or_tty->print_cr("\nG1 full GC for Metaspace");
 238     }
 239   }
 240 }
 241 
 242 void VM_CollectForMetadataAllocation::doit() {
 243   SvcGCMarker sgcm(SvcGCMarker::FULL);
 244 
 245   CollectedHeap* heap = Universe::heap();
 246   GCCauseSetter gccs(heap, _gc_cause);
 247 
 248   // Check again if the space is available.  Another thread
 249   // may have similarly failed a metadata allocation and induced
 250   // a GC that freed space for the allocation.
 251   if (!MetadataAllocationFailALot) {
 252     _result = _loader_data->metaspace_non_null()->allocate(_size, _mdtype);
 253     if (_result != NULL) {
 254       return;
 255     }
 256   }
 257 
 258   if (initiate_concurrent_GC()) {
 259     // For CMS and G1 expand since the collection is going to be concurrent.
 260     _result = _loader_data->metaspace_non_null()->expand_and_allocate(_size, _mdtype);
 261     if (_result != NULL) {
 262       return;
 263     }
 264 
 265     log_metaspace_alloc_failure_for_concurrent_GC();
 266   }
 267 
 268   // Don't clear the soft refs yet.
 269   heap->collect_as_vm_thread(GCCause::_metadata_GC_threshold);
 270   // After a GC try to allocate without expanding.  Could fail
 271   // and expansion will be tried below.
 272   _result = _loader_data->metaspace_non_null()->allocate(_size, _mdtype);
 273   if (_result != NULL) {
 274     return;
 275   }
 276 
 277   // If still failing, allow the Metaspace to expand.
 278   // See delta_capacity_until_GC() for explanation of the
 279   // amount of the expansion.
 280   // This should work unless there really is no more space
 281   // or a MaxMetaspaceSize has been specified on the command line.
 282   _result = _loader_data->metaspace_non_null()->expand_and_allocate(_size, _mdtype);
 283   if (_result != NULL) {
 284     return;
 285   }
 286 
 287   // If expansion failed, do a last-ditch collection and try allocating
 288   // again.  A last-ditch collection will clear softrefs.  This
 289   // behavior is similar to the last-ditch collection done for perm
 290   // gen when it was full and a collection for failed allocation
 291   // did not free perm gen space.
 292   heap->collect_as_vm_thread(GCCause::_last_ditch_collection);
 293   _result = _loader_data->metaspace_non_null()->allocate(_size, _mdtype);
 294   if (_result != NULL) {
 295     return;
 296   }
 297 
 298   if (Verbose && PrintGCDetails) {
 299     gclog_or_tty->print_cr("\nAfter Metaspace GC failed to allocate size "
 300                            SIZE_FORMAT, _size);
 301   }
 302 
 303   if (GC_locker::is_active_and_needs_gc()) {
 304     set_gc_locked();
 305   }
 306 }
 307 
 308 VM_CollectForAllocation::VM_CollectForAllocation(size_t word_size, uint gc_count_before, GCCause::Cause cause)
 309     : VM_GC_Operation(gc_count_before, cause), _result(NULL), _word_size(word_size) {
 310   // Only report if operation was really caused by an allocation.
 311   if (_word_size != 0) {
 312     AllocTracer::send_allocation_requiring_gc_event(_word_size * HeapWordSize);
 313   }
 314 }
--- EOF ---