memTracker.cpp revision 6347:dc427574bc7a
1100966Siwasaki/* 2100966Siwasaki * Copyright (c) 2012, 2013, Oracle and/or its affiliates. All rights reserved. 3100966Siwasaki * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. 4100966Siwasaki * 5100966Siwasaki * This code is free software; you can redistribute it and/or modify it 6100966Siwasaki * under the terms of the GNU General Public License version 2 only, as 7100966Siwasaki * published by the Free Software Foundation. 8100966Siwasaki * 9100966Siwasaki * This code is distributed in the hope that it will be useful, but WITHOUT 10100966Siwasaki * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 11193267Sjkim * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 12100966Siwasaki * version 2 for more details (a copy is included in the LICENSE file that 13100966Siwasaki * accompanied this code). 14100966Siwasaki * 15100966Siwasaki * You should have received a copy of the GNU General Public License version 16100966Siwasaki * 2 along with this work; if not, write to the Free Software Foundation, 17100966Siwasaki * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 18100966Siwasaki * 19100966Siwasaki * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 20100966Siwasaki * or visit www.oracle.com if you need additional information or have any 21100966Siwasaki * questions. 22100966Siwasaki * 23100966Siwasaki */ 24100966Siwasaki#include "precompiled.hpp" 25100966Siwasaki 26100966Siwasaki#include "oops/instanceKlass.hpp" 27100966Siwasaki#include "runtime/atomic.hpp" 28100966Siwasaki#include "runtime/interfaceSupport.hpp" 29100966Siwasaki#include "runtime/mutexLocker.hpp" 30100966Siwasaki#include "runtime/safepoint.hpp" 31100966Siwasaki#include "runtime/threadCritical.hpp" 32100966Siwasaki#include "runtime/vm_operations.hpp" 33100966Siwasaki#include "services/memPtr.hpp" 34100966Siwasaki#include "services/memReporter.hpp" 35100966Siwasaki#include "services/memTracker.hpp" 36100966Siwasaki#include "utilities/decoder.hpp" 37100966Siwasaki#include "utilities/defaultStream.hpp" 38100966Siwasaki#include "utilities/globalDefinitions.hpp" 39100966Siwasaki 40100966Siwasakibool NMT_track_callsite = false; 41100966Siwasaki 42100966Siwasaki// walk all 'known' threads at NMT sync point, and collect their recorders 43100966Siwasakivoid SyncThreadRecorderClosure::do_thread(Thread* thread) { 44100966Siwasaki assert(SafepointSynchronize::is_at_safepoint(), "Safepoint required"); 45100966Siwasaki if (thread->is_Java_thread()) { 46100966Siwasaki JavaThread* javaThread = (JavaThread*)thread; 47100966Siwasaki MemRecorder* recorder = javaThread->get_recorder(); 48100966Siwasaki if (recorder != NULL) { 49100966Siwasaki MemTracker::enqueue_pending_recorder(recorder); 50100966Siwasaki javaThread->set_recorder(NULL); 51100966Siwasaki } 52100966Siwasaki } 53100966Siwasaki _thread_count ++; 54100966Siwasaki} 55100966Siwasaki 56100966Siwasaki 57100966SiwasakiMemRecorder* volatile MemTracker::_global_recorder = NULL; 58100966SiwasakiMemSnapshot* MemTracker::_snapshot = NULL; 59100966SiwasakiMemBaseline MemTracker::_baseline; 60100966SiwasakiMutex* MemTracker::_query_lock = NULL; 61100966SiwasakiMemRecorder* volatile MemTracker::_merge_pending_queue = NULL; 62100966SiwasakiMemRecorder* volatile MemTracker::_pooled_recorders = NULL; 63100966SiwasakiMemTrackWorker* MemTracker::_worker_thread = NULL; 64100966Siwasakiint MemTracker::_sync_point_skip_count = 0; 65100966SiwasakiMemTracker::NMTLevel MemTracker::_tracking_level = MemTracker::NMT_off; 66100966Siwasakivolatile MemTracker::NMTStates MemTracker::_state = NMT_uninited; 67100966SiwasakiMemTracker::ShutdownReason MemTracker::_reason = NMT_shutdown_none; 68100966Siwasakiint MemTracker::_thread_count = 255; 69100966Siwasakivolatile jint MemTracker::_pooled_recorder_count = 0; 70100966Siwasakivolatile unsigned long MemTracker::_processing_generation = 0; 71100966Siwasakivolatile bool MemTracker::_worker_thread_idle = false; 72100966Siwasakivolatile jint MemTracker::_pending_op_count = 0; 73100966Siwasakivolatile bool MemTracker::_slowdown_calling_thread = false; 74100966Siwasakidebug_only(intx MemTracker::_main_thread_tid = 0;) 75100966SiwasakiNOT_PRODUCT(volatile jint MemTracker::_pending_recorder_count = 0;) 76100966Siwasaki 77100966Siwasakivoid MemTracker::init_tracking_options(const char* option_line) { 78100966Siwasaki _tracking_level = NMT_off; 79100966Siwasaki if (strcmp(option_line, "=summary") == 0) { 80100966Siwasaki _tracking_level = NMT_summary; 81100966Siwasaki } else if (strcmp(option_line, "=detail") == 0) { 82100966Siwasaki // detail relies on a stack-walking ability that may not 83100966Siwasaki // be available depending on platform and/or compiler flags 84100966Siwasaki#if PLATFORM_NATIVE_STACK_WALKING_SUPPORTED 85100966Siwasaki _tracking_level = NMT_detail; 86100966Siwasaki#else 87100966Siwasaki jio_fprintf(defaultStream::error_stream(), 88100966Siwasaki "NMT detail is not supported on this platform. Using NMT summary instead.\n"); 89100966Siwasaki _tracking_level = NMT_summary; 90100966Siwasaki#endif 91100966Siwasaki } else if (strcmp(option_line, "=off") != 0) { 92100966Siwasaki vm_exit_during_initialization("Syntax error, expecting -XX:NativeMemoryTracking=[off|summary|detail]", NULL); 93100966Siwasaki } 94100966Siwasaki} 95100966Siwasaki 96100966Siwasaki// first phase of bootstrapping, when VM is still in single-threaded mode. 97100966Siwasakivoid MemTracker::bootstrap_single_thread() { 98100966Siwasaki if (_tracking_level > NMT_off) { 99100966Siwasaki assert(_state == NMT_uninited, "wrong state"); 100100966Siwasaki 101100966Siwasaki // NMT is not supported with UseMallocOnly is on. NMT can NOT 102100966Siwasaki // handle the amount of malloc data without significantly impacting 103100966Siwasaki // runtime performance when this flag is on. 104100966Siwasaki if (UseMallocOnly) { 105100966Siwasaki shutdown(NMT_use_malloc_only); 106100966Siwasaki return; 107100966Siwasaki } 108100966Siwasaki 109100966Siwasaki _query_lock = new (std::nothrow) Mutex(Monitor::max_nonleaf, "NMT_queryLock"); 110100966Siwasaki if (_query_lock == NULL) { 111100966Siwasaki shutdown(NMT_out_of_memory); 112100966Siwasaki return; 113100966Siwasaki } 114100966Siwasaki 115100966Siwasaki debug_only(_main_thread_tid = os::current_thread_id();) 116100966Siwasaki _state = NMT_bootstrapping_single_thread; 117100966Siwasaki NMT_track_callsite = (_tracking_level == NMT_detail && can_walk_stack()); 118100966Siwasaki } 119193341Sjkim} 120100966Siwasaki 121100966Siwasaki// second phase of bootstrapping, when VM is about to or already entered multi-theaded mode. 122100966Siwasakivoid MemTracker::bootstrap_multi_thread() { 123100966Siwasaki if (_tracking_level > NMT_off && _state == NMT_bootstrapping_single_thread) { 124100966Siwasaki // create nmt lock for multi-thread execution 125100966Siwasaki assert(_main_thread_tid == os::current_thread_id(), "wrong thread"); 126167802Sjkim _state = NMT_bootstrapping_multi_thread; 127100966Siwasaki NMT_track_callsite = (_tracking_level == NMT_detail && can_walk_stack()); 128128212Snjl } 129167802Sjkim} 130167802Sjkim 131167802Sjkim// fully start nmt 132167802Sjkimvoid MemTracker::start() { 133167802Sjkim // Native memory tracking is off from command line option 134100966Siwasaki if (_tracking_level == NMT_off || shutdown_in_progress()) return; 135167802Sjkim 136100966Siwasaki assert(_main_thread_tid == os::current_thread_id(), "wrong thread"); 137167802Sjkim assert(_state == NMT_bootstrapping_multi_thread, "wrong state"); 138167802Sjkim 139167802Sjkim _snapshot = new (std::nothrow)MemSnapshot(); 140167802Sjkim if (_snapshot != NULL) { 141167802Sjkim if (!_snapshot->out_of_memory() && start_worker(_snapshot)) { 142167802Sjkim _state = NMT_started; 143167802Sjkim NMT_track_callsite = (_tracking_level == NMT_detail && can_walk_stack()); 144167802Sjkim return; 145167802Sjkim } 146167802Sjkim 147167802Sjkim delete _snapshot; 148167802Sjkim _snapshot = NULL; 149167802Sjkim } 150167802Sjkim 151167802Sjkim // fail to start native memory tracking, shut it down 152167802Sjkim shutdown(NMT_initialization); 153167802Sjkim} 154167802Sjkim 155167802Sjkim/** 156167802Sjkim * Shutting down native memory tracking. 157167802Sjkim * We can not shutdown native memory tracking immediately, so we just 158167802Sjkim * setup shutdown pending flag, every native memory tracking component 159167802Sjkim * should orderly shut itself down. 160167802Sjkim * 161167802Sjkim * The shutdown sequences: 162167802Sjkim * 1. MemTracker::shutdown() sets MemTracker to shutdown pending state 163167802Sjkim * 2. Worker thread calls MemTracker::final_shutdown(), which transites 164193267Sjkim * MemTracker to final shutdown state. 165193267Sjkim * 3. At sync point, MemTracker does final cleanup, before sets memory 166193267Sjkim * tracking level to off to complete shutdown. 167193267Sjkim */ 168193267Sjkimvoid MemTracker::shutdown(ShutdownReason reason) { 169193267Sjkim if (_tracking_level == NMT_off) return; 170193267Sjkim 171193267Sjkim if (_state <= NMT_bootstrapping_single_thread) { 172193267Sjkim // we still in single thread mode, there is not contention 173193267Sjkim _state = NMT_shutdown_pending; 174197104Sjkim _reason = reason; 175197104Sjkim } else { 176167802Sjkim // we want to know who initialized shutdown 177197104Sjkim if ((jint)NMT_started == Atomic::cmpxchg((jint)NMT_shutdown_pending, 178167802Sjkim (jint*)&_state, (jint)NMT_started)) { 179193267Sjkim _reason = reason; 180167802Sjkim } 181167802Sjkim } 182167802Sjkim} 183167802Sjkim 184167802Sjkim// final phase of shutdown 185193267Sjkimvoid MemTracker::final_shutdown() { 186193267Sjkim // delete all pending recorders and pooled recorders 187167802Sjkim delete_all_pending_recorders(); 188167802Sjkim delete_all_pooled_recorders(); 189167802Sjkim 190167802Sjkim { 191167802Sjkim // shared baseline and snapshot are the only objects needed to 192100966Siwasaki // create query results 193100966Siwasaki MutexLockerEx locker(_query_lock, true); 194100966Siwasaki // cleanup baseline data and snapshot 195167802Sjkim _baseline.clear(); 196167802Sjkim delete _snapshot; 197100966Siwasaki _snapshot = NULL; 198167802Sjkim } 199151937Sjkim 200100966Siwasaki // shutdown shared decoder instance, since it is only 201100966Siwasaki // used by native memory tracking so far. 202100966Siwasaki Decoder::shutdown(); 203100966Siwasaki 204100966Siwasaki MemTrackWorker* worker = NULL; 205100966Siwasaki { 206100966Siwasaki ThreadCritical tc; 207100966Siwasaki // can not delete worker inside the thread critical 208100966Siwasaki if (_worker_thread != NULL && Thread::current() == _worker_thread) { 209167802Sjkim worker = _worker_thread; 210167802Sjkim _worker_thread = NULL; 211167802Sjkim } 212167802Sjkim } 213100966Siwasaki if (worker != NULL) { 214167802Sjkim delete worker; 215167802Sjkim } 216167802Sjkim _state = NMT_final_shutdown; 217167802Sjkim} 218167802Sjkim 219167802Sjkim// delete all pooled recorders 220167802Sjkimvoid MemTracker::delete_all_pooled_recorders() { 221167802Sjkim // free all pooled recorders 222167802Sjkim MemRecorder* volatile cur_head = _pooled_recorders; 223167802Sjkim if (cur_head != NULL) { 224167802Sjkim MemRecorder* null_ptr = NULL; 225167802Sjkim while (cur_head != NULL && (void*)cur_head != Atomic::cmpxchg_ptr((void*)null_ptr, 226167802Sjkim (void*)&_pooled_recorders, (void*)cur_head)) { 227167802Sjkim cur_head = _pooled_recorders; 228167802Sjkim } 229167802Sjkim if (cur_head != NULL) { 230167802Sjkim delete cur_head; 231167802Sjkim _pooled_recorder_count = 0; 232167802Sjkim } 233167802Sjkim } 234193267Sjkim} 235167802Sjkim 236167802Sjkim// delete all recorders in pending queue 237167802Sjkimvoid MemTracker::delete_all_pending_recorders() { 238167802Sjkim // free all pending recorders 239167802Sjkim MemRecorder* pending_head = get_pending_recorders(); 240167802Sjkim if (pending_head != NULL) { 241167802Sjkim delete pending_head; 242167802Sjkim } 243193267Sjkim} 244197104Sjkim 245167802Sjkim/* 246193267Sjkim * retrieve per-thread recorder of specified thread. 247193267Sjkim * if thread == NULL, it means global recorder 248193267Sjkim */ 249167802SjkimMemRecorder* MemTracker::get_thread_recorder(JavaThread* thread) { 250167802Sjkim if (shutdown_in_progress()) return NULL; 251167802Sjkim 252193267Sjkim MemRecorder* rc; 253167802Sjkim if (thread == NULL) { 254167802Sjkim rc = _global_recorder; 255193267Sjkim } else { 256193267Sjkim rc = thread->get_recorder(); 257193267Sjkim } 258197104Sjkim 259193267Sjkim if (rc != NULL && rc->is_full()) { 260193267Sjkim enqueue_pending_recorder(rc); 261193267Sjkim rc = NULL; 262193267Sjkim } 263193267Sjkim 264197104Sjkim if (rc == NULL) { 265167802Sjkim rc = get_new_or_pooled_instance(); 266197104Sjkim if (thread == NULL) { 267197104Sjkim _global_recorder = rc; 268197104Sjkim } else { 269197104Sjkim thread->set_recorder(rc); 270197104Sjkim } 271197104Sjkim } 272197104Sjkim return rc; 273197104Sjkim} 274167802Sjkim 275167802Sjkim/* 276167802Sjkim * get a per-thread recorder from pool, or create a new one if 277167802Sjkim * there is not one available. 278167802Sjkim */ 279167802SjkimMemRecorder* MemTracker::get_new_or_pooled_instance() { 280167802Sjkim MemRecorder* cur_head = const_cast<MemRecorder*> (_pooled_recorders); 281167802Sjkim if (cur_head == NULL) { 282167802Sjkim MemRecorder* rec = new (std::nothrow)MemRecorder(); 283167802Sjkim if (rec == NULL || rec->out_of_memory()) { 284193267Sjkim shutdown(NMT_out_of_memory); 285193267Sjkim if (rec != NULL) { 286167802Sjkim delete rec; 287167802Sjkim rec = NULL; 288167802Sjkim } 289197104Sjkim } 290197104Sjkim return rec; 291167802Sjkim } else { 292167802Sjkim MemRecorder* next_head = cur_head->next(); 293167802Sjkim if ((void*)cur_head != Atomic::cmpxchg_ptr((void*)next_head, (void*)&_pooled_recorders, 294193267Sjkim (void*)cur_head)) { 295167802Sjkim return get_new_or_pooled_instance(); 296167802Sjkim } 297167802Sjkim cur_head->set_next(NULL); 298167802Sjkim Atomic::dec(&_pooled_recorder_count); 299193267Sjkim cur_head->set_generation(); 300167802Sjkim return cur_head; 301167802Sjkim } 302193267Sjkim} 303167802Sjkim 304197104Sjkim/* 305197104Sjkim * retrieve all recorders in pending queue, and empty the queue 306197104Sjkim */ 307197104SjkimMemRecorder* MemTracker::get_pending_recorders() { 308167802Sjkim MemRecorder* cur_head = const_cast<MemRecorder*>(_merge_pending_queue); 309167802Sjkim MemRecorder* null_ptr = NULL; 310167802Sjkim while ((void*)cur_head != Atomic::cmpxchg_ptr((void*)null_ptr, (void*)&_merge_pending_queue, 311100966Siwasaki (void*)cur_head)) { 312167802Sjkim cur_head = const_cast<MemRecorder*>(_merge_pending_queue); 313167802Sjkim } 314167802Sjkim NOT_PRODUCT(Atomic::store(0, &_pending_recorder_count)); 315167802Sjkim return cur_head; 316167802Sjkim} 317167802Sjkim 318193267Sjkim/* 319167802Sjkim * release a recorder to recorder pool. 320167802Sjkim */ 321167802Sjkimvoid MemTracker::release_thread_recorder(MemRecorder* rec) { 322167802Sjkim assert(rec != NULL, "null recorder"); 323167802Sjkim // we don't want to pool too many recorders 324167802Sjkim rec->set_next(NULL); 325167802Sjkim if (shutdown_in_progress() || _pooled_recorder_count > _thread_count * 2) { 326167802Sjkim delete rec; 327167802Sjkim return; 328167802Sjkim } 329167802Sjkim 330167802Sjkim rec->clear(); 331167802Sjkim MemRecorder* cur_head = const_cast<MemRecorder*>(_pooled_recorders); 332167802Sjkim rec->set_next(cur_head); 333167802Sjkim while ((void*)cur_head != Atomic::cmpxchg_ptr((void*)rec, (void*)&_pooled_recorders, 334167802Sjkim (void*)cur_head)) { 335167802Sjkim cur_head = const_cast<MemRecorder*>(_pooled_recorders); 336167802Sjkim rec->set_next(cur_head); 337167802Sjkim } 338167802Sjkim Atomic::inc(&_pooled_recorder_count); 339167802Sjkim} 340167802Sjkim 341167802Sjkim// write a record to proper recorder. No lock can be taken from this method 342167802Sjkim// down. 343167802Sjkimvoid MemTracker::write_tracking_record(address addr, MEMFLAGS flags, 344167802Sjkim size_t size, jint seq, address pc, JavaThread* thread) { 345167802Sjkim 346167802Sjkim MemRecorder* rc = get_thread_recorder(thread); 347167802Sjkim if (rc != NULL) { 348167802Sjkim rc->record(addr, flags, size, seq, pc); 349167802Sjkim } 350167802Sjkim} 351167802Sjkim 352167802Sjkim/** 353167802Sjkim * enqueue a recorder to pending queue 354167802Sjkim */ 355167802Sjkimvoid MemTracker::enqueue_pending_recorder(MemRecorder* rec) { 356193267Sjkim assert(rec != NULL, "null recorder"); 357193267Sjkim 358193267Sjkim // we are shutting down, so just delete it 359193267Sjkim if (shutdown_in_progress()) { 360193267Sjkim rec->set_next(NULL); 361193267Sjkim delete rec; 362193267Sjkim return; 363193267Sjkim } 364167802Sjkim 365167802Sjkim MemRecorder* cur_head = const_cast<MemRecorder*>(_merge_pending_queue); 366167802Sjkim rec->set_next(cur_head); 367167802Sjkim while ((void*)cur_head != Atomic::cmpxchg_ptr((void*)rec, (void*)&_merge_pending_queue, 368193267Sjkim (void*)cur_head)) { 369167802Sjkim cur_head = const_cast<MemRecorder*>(_merge_pending_queue); 370167802Sjkim rec->set_next(cur_head); 371167802Sjkim } 372197104Sjkim NOT_PRODUCT(Atomic::inc(&_pending_recorder_count);) 373197104Sjkim} 374197104Sjkim 375197104Sjkim/* 376167802Sjkim * The method is called at global safepoint 377167802Sjkim * during it synchronization process. 378167802Sjkim * 1. enqueue all JavaThreads' per-thread recorders 379167802Sjkim * 2. enqueue global recorder 380167802Sjkim * 3. retrieve all pending recorders 381167802Sjkim * 4. reset global sequence number generator 382167802Sjkim * 5. call worker's sync 383197104Sjkim */ 384197104Sjkim#define MAX_SAFEPOINTS_TO_SKIP 128 385197104Sjkim#define SAFE_SEQUENCE_THRESHOLD 30 386197104Sjkim#define HIGH_GENERATION_THRESHOLD 60 387167802Sjkim#define MAX_RECORDER_THREAD_RATIO 30 388167802Sjkim#define MAX_RECORDER_PER_THREAD 100 389167802Sjkim 390167802Sjkimvoid MemTracker::sync() { 391167802Sjkim assert(_tracking_level > NMT_off, "NMT is not enabled"); 392167802Sjkim assert(SafepointSynchronize::is_at_safepoint(), "Safepoint required"); 393167802Sjkim 394167802Sjkim // Some GC tests hit large number of safepoints in short period of time 395167802Sjkim // without meaningful activities. We should prevent going to 396167802Sjkim // sync point in these cases, which can potentially exhaust generation buffer. 397167802Sjkim // Here is the factots to determine if we should go into sync point: 398167802Sjkim // 1. not to overflow sequence number 399167802Sjkim // 2. if we are in danger to overflow generation buffer 400193267Sjkim // 3. how many safepoints we already skipped sync point 401193267Sjkim if (_state == NMT_started) { 402193267Sjkim // worker thread is not ready, no one can manage generation 403193267Sjkim // buffer, so skip this safepoint 404197104Sjkim if (_worker_thread == NULL) return; 405197104Sjkim 406197104Sjkim if (_sync_point_skip_count < MAX_SAFEPOINTS_TO_SKIP) { 407197104Sjkim int per_seq_in_use = SequenceGenerator::peek() * 100 / max_jint; 408167802Sjkim int per_gen_in_use = _worker_thread->generations_in_use() * 100 / MAX_GENERATIONS; 409167802Sjkim if (per_seq_in_use < SAFE_SEQUENCE_THRESHOLD && per_gen_in_use >= HIGH_GENERATION_THRESHOLD) { 410167802Sjkim _sync_point_skip_count ++; 411167802Sjkim return; 412167802Sjkim } 413100966Siwasaki } 414100966Siwasaki { 415100966Siwasaki // This method is running at safepoint, with ThreadCritical lock, 416100966Siwasaki // it should guarantee that NMT is fully sync-ed. 417100966Siwasaki ThreadCritical tc; 418100966Siwasaki 419100966Siwasaki // We can NOT execute NMT sync-point if there are pending tracking ops. 420100966Siwasaki if (_pending_op_count == 0) { 421167802Sjkim SequenceGenerator::reset(); 422167802Sjkim _sync_point_skip_count = 0; 423167802Sjkim 424167802Sjkim // walk all JavaThreads to collect recorders 425167802Sjkim SyncThreadRecorderClosure stc; 426167802Sjkim Threads::threads_do(&stc); 427100966Siwasaki 428167802Sjkim _thread_count = stc.get_thread_count(); 429151937Sjkim MemRecorder* pending_recorders = get_pending_recorders(); 430151937Sjkim 431151937Sjkim if (_global_recorder != NULL) { 432100966Siwasaki _global_recorder->set_next(pending_recorders); 433100966Siwasaki pending_recorders = _global_recorder; 434100966Siwasaki _global_recorder = NULL; 435102550Siwasaki } 436100966Siwasaki 437100966Siwasaki // see if NMT has too many outstanding recorder instances, it usually 438100966Siwasaki // means that worker thread is lagging behind in processing them. 439100966Siwasaki if (!AutoShutdownNMT) { 440100966Siwasaki _slowdown_calling_thread = (MemRecorder::_instance_count > MAX_RECORDER_THREAD_RATIO * _thread_count); 441100966Siwasaki } else { 442100966Siwasaki // If auto shutdown is on, enforce MAX_RECORDER_PER_THREAD threshold to prevent OOM 443100966Siwasaki if (MemRecorder::_instance_count >= _thread_count * MAX_RECORDER_PER_THREAD) { 444100966Siwasaki shutdown(NMT_out_of_memory); 445100966Siwasaki } 446100966Siwasaki } 447100966Siwasaki 448100966Siwasaki // check _worker_thread with lock to avoid racing condition 449100966Siwasaki if (_worker_thread != NULL) { 450100966Siwasaki _worker_thread->at_sync_point(pending_recorders, InstanceKlass::number_of_instance_classes()); 451100966Siwasaki } 452100966Siwasaki assert(SequenceGenerator::peek() == 1, "Should not have memory activities during sync-point"); 453100966Siwasaki } else { 454100966Siwasaki _sync_point_skip_count ++; 455100966Siwasaki } 456100966Siwasaki } 457100966Siwasaki } 458100966Siwasaki 459100966Siwasaki // now, it is the time to shut whole things off 460100966Siwasaki if (_state == NMT_final_shutdown) { 461100966Siwasaki // walk all JavaThreads to delete all recorders 462100966Siwasaki SyncThreadRecorderClosure stc; 463100966Siwasaki Threads::threads_do(&stc); 464100966Siwasaki // delete global recorder 465100966Siwasaki { 466100966Siwasaki ThreadCritical tc; 467102550Siwasaki if (_global_recorder != NULL) { 468151937Sjkim delete _global_recorder; 469117521Snjl _global_recorder = NULL; 470151937Sjkim } 471151937Sjkim } 472193267Sjkim MemRecorder* pending_recorders = get_pending_recorders(); 473117521Snjl if (pending_recorders != NULL) { 474151937Sjkim delete pending_recorders; 475151937Sjkim } 476151937Sjkim // try at a later sync point to ensure MemRecorder instance drops to zero to 477151937Sjkim // completely shutdown NMT 478151937Sjkim if (MemRecorder::_instance_count == 0) { 479117521Snjl _state = NMT_shutdown; 480151937Sjkim _tracking_level = NMT_off; 481151937Sjkim } 482117521Snjl } 483151937Sjkim} 484151937Sjkim 485151937Sjkim/* 486151937Sjkim * Start worker thread. 487117521Snjl */ 488117521Snjlbool MemTracker::start_worker(MemSnapshot* snapshot) { 489117521Snjl assert(_worker_thread == NULL && _snapshot != NULL, "Just Check"); 490117521Snjl _worker_thread = new (std::nothrow) MemTrackWorker(snapshot); 491117521Snjl if (_worker_thread == NULL) { 492117521Snjl return false; 493117521Snjl } else if (_worker_thread->has_error()) { 494117521Snjl delete _worker_thread; 495117521Snjl _worker_thread = NULL; 496117521Snjl return false; 497117521Snjl } 498117521Snjl _worker_thread->start(); 499117521Snjl return true; 500117521Snjl} 501117521Snjl 502117521Snjl/* 503117521Snjl * We need to collect a JavaThread's per-thread recorder 504117521Snjl * before it exits. 505117521Snjl */ 506117521Snjlvoid MemTracker::thread_exiting(JavaThread* thread) { 507117521Snjl if (is_on()) { 508100966Siwasaki MemRecorder* rec = thread->get_recorder(); 509100966Siwasaki if (rec != NULL) { 510151937Sjkim enqueue_pending_recorder(rec); 511151937Sjkim thread->set_recorder(NULL); 512151937Sjkim } 513151937Sjkim } 514151937Sjkim} 515100966Siwasaki 516100966Siwasaki// baseline current memory snapshot 517151937Sjkimbool MemTracker::baseline() { 518151937Sjkim MutexLocker lock(_query_lock); 519100966Siwasaki MemSnapshot* snapshot = get_snapshot(); 520100966Siwasaki if (snapshot != NULL) { 521100966Siwasaki return _baseline.baseline(*snapshot, false); 522151937Sjkim } 523151937Sjkim return false; 524151937Sjkim} 525151937Sjkim 526100966Siwasaki// print memory usage from current snapshot 527100966Siwasakibool MemTracker::print_memory_usage(BaselineOutputer& out, size_t unit, bool summary_only) { 528100966Siwasaki MemBaseline baseline; 529100966Siwasaki MutexLocker lock(_query_lock); 530100966Siwasaki MemSnapshot* snapshot = get_snapshot(); 531100966Siwasaki if (snapshot != NULL && baseline.baseline(*snapshot, summary_only)) { 532100966Siwasaki BaselineReporter reporter(out, unit); 533100966Siwasaki reporter.report_baseline(baseline, summary_only); 534100966Siwasaki return true; 535100966Siwasaki } 536100966Siwasaki return false; 537100966Siwasaki} 538100966Siwasaki 539198237Sjkim// Whitebox API for blocking until the current generation of NMT data has been merged 540198237Sjkimbool MemTracker::wbtest_wait_for_data_merge() { 541198237Sjkim // NMT can't be shutdown while we're holding _query_lock 542198237Sjkim MutexLocker lock(_query_lock); 543198237Sjkim assert(_worker_thread != NULL, "Invalid query"); 544198237Sjkim // the generation at query time, so NMT will spin till this generation is processed 545198237Sjkim unsigned long generation_at_query_time = SequenceGenerator::current_generation(); 546198237Sjkim unsigned long current_processing_generation = _processing_generation; 547198237Sjkim // if generation counter overflown 548198237Sjkim bool generation_overflown = (generation_at_query_time < current_processing_generation); 549198237Sjkim long generations_to_wrap = MAX_UNSIGNED_LONG - current_processing_generation; 550198237Sjkim // spin 551198237Sjkim while (!shutdown_in_progress()) { 552198237Sjkim if (!generation_overflown) { 553198237Sjkim if (current_processing_generation > generation_at_query_time) { 554198237Sjkim return true; 555198237Sjkim } 556198237Sjkim } else { 557198237Sjkim assert(generations_to_wrap >= 0, "Sanity check"); 558198237Sjkim long current_generations_to_wrap = MAX_UNSIGNED_LONG - current_processing_generation; 559198237Sjkim assert(current_generations_to_wrap >= 0, "Sanity check"); 560198237Sjkim // to overflow an unsigned long should take long time, so to_wrap check should be sufficient 561198237Sjkim if (current_generations_to_wrap > generations_to_wrap && 562198237Sjkim current_processing_generation > generation_at_query_time) { 563198237Sjkim return true; 564198237Sjkim } 565198237Sjkim } 566100966Siwasaki 567100966Siwasaki // if worker thread is idle, but generation is not advancing, that means 568151937Sjkim // there is not safepoint to let NMT advance generation, force one. 569151937Sjkim if (_worker_thread_idle) { 570151937Sjkim VM_ForceSafepoint vfs; 571151937Sjkim VMThread::execute(&vfs); 572100966Siwasaki } 573100966Siwasaki MemSnapshot* snapshot = get_snapshot(); 574151937Sjkim if (snapshot == NULL) { 575151937Sjkim return false; 576151937Sjkim } 577100966Siwasaki snapshot->wait(1000); 578100966Siwasaki current_processing_generation = _processing_generation; 579151937Sjkim } 580151937Sjkim // We end up here if NMT is shutting down before our data has been merged 581151937Sjkim return false; 582100966Siwasaki} 583100966Siwasaki 584151937Sjkim// compare memory usage between current snapshot and baseline 585151937Sjkimbool MemTracker::compare_memory_usage(BaselineOutputer& out, size_t unit, bool summary_only) { 586151937Sjkim MutexLocker lock(_query_lock); 587151937Sjkim if (_baseline.baselined()) { 588151937Sjkim MemBaseline baseline; 589151937Sjkim MemSnapshot* snapshot = get_snapshot(); 590102550Siwasaki if (snapshot != NULL && baseline.baseline(*snapshot, summary_only)) { 591167802Sjkim BaselineReporter reporter(out, unit); 592100966Siwasaki reporter.diff_baselines(baseline, _baseline, summary_only); 593100966Siwasaki return true; 594100966Siwasaki } 595167802Sjkim } 596151937Sjkim return false; 597100966Siwasaki} 598100966Siwasaki 599100966Siwasaki#ifndef PRODUCT 600100966Siwasakivoid MemTracker::walk_stack(int toSkip, char* buf, int len) { 601100966Siwasaki int cur_len = 0; 602100966Siwasaki char tmp[1024]; 603107325Siwasaki address pc; 604167802Sjkim 605167802Sjkim while (cur_len < len) { 606151937Sjkim pc = os::get_caller_pc(toSkip + 1); 607167802Sjkim if (pc != NULL && os::dll_address_to_function_name(pc, tmp, sizeof(tmp), NULL)) { 608100966Siwasaki jio_snprintf(&buf[cur_len], (len - cur_len), "%s\n", tmp); 609100966Siwasaki cur_len = (int)strlen(buf); 610100966Siwasaki } else { 611100966Siwasaki buf[cur_len] = '\0'; 612100966Siwasaki break; 613151937Sjkim } 614100966Siwasaki toSkip ++; 615100966Siwasaki } 616100966Siwasaki} 617100966Siwasaki 618100966Siwasakivoid MemTracker::print_tracker_stats(outputStream* st) { 619151937Sjkim st->print_cr("\nMemory Tracker Stats:"); 620100966Siwasaki st->print_cr("\tMax sequence number = %d", SequenceGenerator::max_seq_num()); 621100966Siwasaki st->print_cr("\tthead count = %d", _thread_count); 622100966Siwasaki st->print_cr("\tArena instance = %d", Arena::_instance_count); 623100966Siwasaki st->print_cr("\tpooled recorder count = %d", _pooled_recorder_count); 624151937Sjkim st->print_cr("\tqueued recorder count = %d", _pending_recorder_count); 625151937Sjkim st->print_cr("\tmemory recorder instance count = %d", MemRecorder::_instance_count); 626151937Sjkim if (_worker_thread != NULL) { 627151937Sjkim st->print_cr("\tWorker thread:"); 628151937Sjkim st->print_cr("\t\tSync point count = %d", _worker_thread->_sync_point_count); 629151937Sjkim st->print_cr("\t\tpending recorder count = %d", _worker_thread->count_pending_recorders()); 630100966Siwasaki st->print_cr("\t\tmerge count = %d", _worker_thread->_merge_count); 631151937Sjkim } else { 632100966Siwasaki st->print_cr("\tWorker thread is not started"); 633100966Siwasaki } 634100966Siwasaki st->print_cr(" "); 635100966Siwasaki 636100966Siwasaki if (_snapshot != NULL) { 637151937Sjkim _snapshot->print_snapshot_stats(st); 638100966Siwasaki } else { 639100966Siwasaki st->print_cr("No snapshot"); 640100966Siwasaki } 641100966Siwasaki} 642100966Siwasaki#endif 643151937Sjkim 644100966Siwasaki 645100966Siwasaki// Tracker Implementation 646100966Siwasaki 647100966Siwasaki/* 648151937Sjkim * Create a tracker. 649151937Sjkim * This is a fairly complicated constructor, as it has to make two important decisions: 650100966Siwasaki * 1) Does it need to take ThreadCritical lock to write tracking record 651100966Siwasaki * 2) Does it need to pre-reserve a sequence number for the tracking record 652100966Siwasaki * 653100966Siwasaki * The rules to determine if ThreadCritical is needed: 654100966Siwasaki * 1. When nmt is in single-threaded bootstrapping mode, no lock is needed as VM 655151937Sjkim * still in single thread mode. 656100966Siwasaki * 2. For all threads other than JavaThread, ThreadCritical is needed 657100966Siwasaki * to write to recorders to global recorder. 658100966Siwasaki * 3. For JavaThreads that are no longer visible by safepoint, also 659100966Siwasaki * need to take ThreadCritical and records are written to global 660100966Siwasaki * recorders, since these threads are NOT walked by Threads.do_thread(). 661151937Sjkim * 4. JavaThreads that are running in safepoint-safe states do not stop 662100966Siwasaki * for safepoints, ThreadCritical lock should be taken to write 663100966Siwasaki * memory records. 664100966Siwasaki * 5. JavaThreads that are running in VM state do not need any lock and 665100966Siwasaki * records are written to per-thread recorders. 666100966Siwasaki * 6. For a thread has yet to attach VM 'Thread', they need to take 667151937Sjkim * ThreadCritical to write to global recorder. 668100966Siwasaki * 669100966Siwasaki * The memory operations that need pre-reserve sequence numbers: 670100966Siwasaki * The memory operations that "release" memory blocks and the 671151937Sjkim * operations can fail, need to pre-reserve sequence number. They 672151937Sjkim * are realloc, uncommit and release. 673151937Sjkim * 674151937Sjkim * The reason for pre-reserve sequence number, is to prevent race condition: 675151937Sjkim * Thread 1 Thread 2 676151937Sjkim * <release> 677100966Siwasaki * <allocate> 678151937Sjkim * <write allocate record> 679100966Siwasaki * <write release record> 680100966Siwasaki * if Thread 2 happens to obtain the memory address Thread 1 just released, 681100966Siwasaki * then NMT can mistakenly report the memory is free. 682100966Siwasaki * 683100966Siwasaki * Noticeably, free() does not need pre-reserve sequence number, because the call 684151937Sjkim * does not fail, so we can alway write "release" record before the memory is actaully 685100966Siwasaki * freed. 686100966Siwasaki * 687100966Siwasaki * For realloc, uncommit and release, following coding pattern should be used: 688100966Siwasaki * 689100966Siwasaki * MemTracker::Tracker tkr = MemTracker::get_realloc_tracker(); 690151937Sjkim * ptr = ::realloc(...); 691100966Siwasaki * if (ptr == NULL) { 692100966Siwasaki * tkr.record(...) 693100966Siwasaki * } else { 694100966Siwasaki * tkr.discard(); 695100966Siwasaki * } 696151937Sjkim * 697100966Siwasaki * MemTracker::Tracker tkr = MemTracker::get_virtual_memory_uncommit_tracker(); 698100966Siwasaki * if (uncommit(...)) { 699100966Siwasaki * tkr.record(...); 700100966Siwasaki * } else { 701100966Siwasaki * tkr.discard(); 702151937Sjkim * } 703100966Siwasaki * 704100966Siwasaki * MemTracker::Tracker tkr = MemTracker::get_virtual_memory_release_tracker(); 705100966Siwasaki * if (release(...)) { 706100966Siwasaki * tkr.record(...); 707100966Siwasaki * } else { 708151937Sjkim * tkr.discard(); 709100966Siwasaki * } 710100966Siwasaki * 711100966Siwasaki * Since pre-reserved sequence number is only good for the generation that it is acquired, 712100966Siwasaki * when there is pending Tracker that reserved sequence number, NMT sync-point has 713100966Siwasaki * to be skipped to prevent from advancing generation. This is done by inc and dec 714151937Sjkim * MemTracker::_pending_op_count, when MemTracker::_pending_op_count > 0, NMT sync-point is skipped. 715100966Siwasaki * Not all pre-reservation of sequence number will increment pending op count. For JavaThreads 716100966Siwasaki * that honor safepoints, safepoint can not occur during the memory operations, so the 717100966Siwasaki * pre-reserved sequence number won't cross the generation boundry. 718100966Siwasaki */ 719100966SiwasakiMemTracker::Tracker::Tracker(MemoryOperation op, Thread* thr) { 720151937Sjkim _op = NoOp; 721100966Siwasaki _seq = 0; 722100966Siwasaki if (MemTracker::is_on()) { 723100966Siwasaki _java_thread = NULL; 724100966Siwasaki _op = op; 725128212Snjl 726128212Snjl // figure out if ThreadCritical lock is needed to write this operation 727128212Snjl // to MemTracker 728128212Snjl if (MemTracker::is_single_threaded_bootstrap()) { 729198237Sjkim thr = NULL; 730198237Sjkim } else if (thr == NULL) { 731128212Snjl // don't use Thread::current(), since it is possible that 732198237Sjkim // the calling thread has yet to attach to VM 'Thread', 733198237Sjkim // which will result assertion failure 734198237Sjkim thr = ThreadLocalStorage::thread(); 735198237Sjkim } 736198237Sjkim 737198237Sjkim if (thr != NULL) { 738198237Sjkim // Check NMT load 739198237Sjkim MemTracker::check_NMT_load(thr); 740198237Sjkim 741198237Sjkim if (thr->is_Java_thread() && ((JavaThread*)thr)->is_safepoint_visible()) { 742198237Sjkim _java_thread = (JavaThread*)thr; 743198237Sjkim JavaThreadState state = _java_thread->thread_state(); 744198237Sjkim // JavaThreads that are safepoint safe, can run through safepoint, 745167802Sjkim // so ThreadCritical is needed to ensure no threads at safepoint create 746167802Sjkim // new records while the records are being gathered and the sequence number is changing 747167802Sjkim _need_thread_critical_lock = 748167802Sjkim SafepointSynchronize::safepoint_safe(_java_thread, state); 749167802Sjkim } else { 750167802Sjkim _need_thread_critical_lock = true; 751167802Sjkim } 752167802Sjkim } else { 753167802Sjkim _need_thread_critical_lock 754167802Sjkim = !MemTracker::is_single_threaded_bootstrap(); 755167802Sjkim } 756167802Sjkim 757100966Siwasaki // see if we need to pre-reserve sequence number for this operation 758 if (_op == Realloc || _op == Uncommit || _op == Release) { 759 if (_need_thread_critical_lock) { 760 ThreadCritical tc; 761 MemTracker::inc_pending_op_count(); 762 _seq = SequenceGenerator::next(); 763 } else { 764 // for the threads that honor safepoints, no safepoint can occur 765 // during the lifespan of tracker, so we don't need to increase 766 // pending op count. 767 _seq = SequenceGenerator::next(); 768 } 769 } 770 } 771} 772 773void MemTracker::Tracker::discard() { 774 if (MemTracker::is_on() && _seq != 0) { 775 if (_need_thread_critical_lock) { 776 ThreadCritical tc; 777 MemTracker::dec_pending_op_count(); 778 } 779 _seq = 0; 780 } 781} 782 783 784void MemTracker::Tracker::record(address old_addr, address new_addr, size_t size, 785 MEMFLAGS flags, address pc) { 786 assert(old_addr != NULL && new_addr != NULL, "Sanity check"); 787 assert(_op == Realloc || _op == NoOp, "Wrong call"); 788 if (MemTracker::is_on() && NMT_CAN_TRACK(flags) && _op != NoOp && !MemTracker::shutdown_in_progress()) { 789 assert(_seq > 0, "Need pre-reserve sequence number"); 790 if (_need_thread_critical_lock) { 791 ThreadCritical tc; 792 // free old address, use pre-reserved sequence number 793 MemTracker::write_tracking_record(old_addr, MemPointerRecord::free_tag(), 794 0, _seq, pc, _java_thread); 795 MemTracker::write_tracking_record(new_addr, flags | MemPointerRecord::malloc_tag(), 796 size, SequenceGenerator::next(), pc, _java_thread); 797 // decrement MemTracker pending_op_count 798 MemTracker::dec_pending_op_count(); 799 } else { 800 // free old address, use pre-reserved sequence number 801 MemTracker::write_tracking_record(old_addr, MemPointerRecord::free_tag(), 802 0, _seq, pc, _java_thread); 803 MemTracker::write_tracking_record(new_addr, flags | MemPointerRecord::malloc_tag(), 804 size, SequenceGenerator::next(), pc, _java_thread); 805 } 806 _seq = 0; 807 } 808} 809 810void MemTracker::Tracker::record(address addr, size_t size, MEMFLAGS flags, address pc) { 811 // OOM already? 812 if (addr == NULL) return; 813 814 if (MemTracker::is_on() && NMT_CAN_TRACK(flags) && _op != NoOp && !MemTracker::shutdown_in_progress()) { 815 bool pre_reserved_seq = (_seq != 0); 816 address pc = CALLER_CALLER_PC; 817 MEMFLAGS orig_flags = flags; 818 819 // or the tagging flags 820 switch(_op) { 821 case Malloc: 822 flags |= MemPointerRecord::malloc_tag(); 823 break; 824 case Free: 825 flags = MemPointerRecord::free_tag(); 826 break; 827 case Realloc: 828 fatal("Use the other Tracker::record()"); 829 break; 830 case Reserve: 831 case ReserveAndCommit: 832 flags |= MemPointerRecord::virtual_memory_reserve_tag(); 833 break; 834 case Commit: 835 flags = MemPointerRecord::virtual_memory_commit_tag(); 836 break; 837 case Type: 838 flags |= MemPointerRecord::virtual_memory_type_tag(); 839 break; 840 case Uncommit: 841 assert(pre_reserved_seq, "Need pre-reserve sequence number"); 842 flags = MemPointerRecord::virtual_memory_uncommit_tag(); 843 break; 844 case Release: 845 assert(pre_reserved_seq, "Need pre-reserve sequence number"); 846 flags = MemPointerRecord::virtual_memory_release_tag(); 847 break; 848 case ArenaSize: 849 // a bit of hack here, add a small postive offset to arena 850 // address for its size record, so the size record is sorted 851 // right after arena record. 852 flags = MemPointerRecord::arena_size_tag(); 853 addr += sizeof(void*); 854 break; 855 case StackRelease: 856 flags = MemPointerRecord::virtual_memory_release_tag(); 857 break; 858 default: 859 ShouldNotReachHere(); 860 } 861 862 // write memory tracking record 863 if (_need_thread_critical_lock) { 864 ThreadCritical tc; 865 if (_seq == 0) _seq = SequenceGenerator::next(); 866 MemTracker::write_tracking_record(addr, flags, size, _seq, pc, _java_thread); 867 if (_op == ReserveAndCommit) { 868 MemTracker::write_tracking_record(addr, orig_flags | MemPointerRecord::virtual_memory_commit_tag(), 869 size, SequenceGenerator::next(), pc, _java_thread); 870 } 871 if (pre_reserved_seq) MemTracker::dec_pending_op_count(); 872 } else { 873 if (_seq == 0) _seq = SequenceGenerator::next(); 874 MemTracker::write_tracking_record(addr, flags, size, _seq, pc, _java_thread); 875 if (_op == ReserveAndCommit) { 876 MemTracker::write_tracking_record(addr, orig_flags | MemPointerRecord::virtual_memory_commit_tag(), 877 size, SequenceGenerator::next(), pc, _java_thread); 878 } 879 } 880 _seq = 0; 881 } 882} 883 884