Mercurial > hg > graal-compiler
view src/share/vm/services/memTracker.cpp @ 9463:902a974d55c8
Merge.
author | Doug Simon <doug.simon@oracle.com> |
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date | Tue, 30 Apr 2013 23:24:25 +0200 |
parents | 4c8bb5e4f68f |
children | 35f8765422b9 |
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/* * Copyright (c) 2012, 2013, Oracle and/or its affiliates. All rights reserved. * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. * * This code is free software; you can redistribute it and/or modify it * under the terms of the GNU General Public License version 2 only, as * published by the Free Software Foundation. * * This code is distributed in the hope that it will be useful, but WITHOUT * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License * version 2 for more details (a copy is included in the LICENSE file that * accompanied this code). * * You should have received a copy of the GNU General Public License version * 2 along with this work; if not, write to the Free Software Foundation, * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. * * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA * or visit www.oracle.com if you need additional information or have any * questions. * */ #include "precompiled.hpp" #include "oops/instanceKlass.hpp" #include "runtime/atomic.hpp" #include "runtime/interfaceSupport.hpp" #include "runtime/mutexLocker.hpp" #include "runtime/safepoint.hpp" #include "runtime/threadCritical.hpp" #include "runtime/vm_operations.hpp" #include "services/memPtr.hpp" #include "services/memReporter.hpp" #include "services/memTracker.hpp" #include "utilities/decoder.hpp" #include "utilities/globalDefinitions.hpp" bool NMT_track_callsite = false; // walk all 'known' threads at NMT sync point, and collect their recorders void SyncThreadRecorderClosure::do_thread(Thread* thread) { assert(SafepointSynchronize::is_at_safepoint(), "Safepoint required"); if (thread->is_Java_thread()) { JavaThread* javaThread = (JavaThread*)thread; MemRecorder* recorder = javaThread->get_recorder(); if (recorder != NULL) { MemTracker::enqueue_pending_recorder(recorder); javaThread->set_recorder(NULL); } } _thread_count ++; } MemRecorder* MemTracker::_global_recorder = NULL; MemSnapshot* MemTracker::_snapshot = NULL; MemBaseline MemTracker::_baseline; Mutex* MemTracker::_query_lock = NULL; volatile MemRecorder* MemTracker::_merge_pending_queue = NULL; volatile MemRecorder* MemTracker::_pooled_recorders = NULL; MemTrackWorker* MemTracker::_worker_thread = NULL; int MemTracker::_sync_point_skip_count = 0; MemTracker::NMTLevel MemTracker::_tracking_level = MemTracker::NMT_off; volatile MemTracker::NMTStates MemTracker::_state = NMT_uninited; MemTracker::ShutdownReason MemTracker::_reason = NMT_shutdown_none; int MemTracker::_thread_count = 255; volatile jint MemTracker::_pooled_recorder_count = 0; volatile unsigned long MemTracker::_processing_generation = 0; volatile bool MemTracker::_worker_thread_idle = false; volatile bool MemTracker::_slowdown_calling_thread = false; debug_only(intx MemTracker::_main_thread_tid = 0;) NOT_PRODUCT(volatile jint MemTracker::_pending_recorder_count = 0;) void MemTracker::init_tracking_options(const char* option_line) { _tracking_level = NMT_off; if (strcmp(option_line, "=summary") == 0) { _tracking_level = NMT_summary; } else if (strcmp(option_line, "=detail") == 0) { _tracking_level = NMT_detail; } else if (strcmp(option_line, "=off") != 0) { vm_exit_during_initialization("Syntax error, expecting -XX:NativeMemoryTracking=[off|summary|detail]", NULL); } } // first phase of bootstrapping, when VM is still in single-threaded mode. void MemTracker::bootstrap_single_thread() { if (_tracking_level > NMT_off) { assert(_state == NMT_uninited, "wrong state"); // NMT is not supported with UseMallocOnly is on. NMT can NOT // handle the amount of malloc data without significantly impacting // runtime performance when this flag is on. if (UseMallocOnly) { shutdown(NMT_use_malloc_only); return; } _query_lock = new (std::nothrow) Mutex(Monitor::max_nonleaf, "NMT_queryLock"); if (_query_lock == NULL) { shutdown(NMT_out_of_memory); return; } debug_only(_main_thread_tid = os::current_thread_id();) _state = NMT_bootstrapping_single_thread; NMT_track_callsite = (_tracking_level == NMT_detail && can_walk_stack()); } } // second phase of bootstrapping, when VM is about to or already entered multi-theaded mode. void MemTracker::bootstrap_multi_thread() { if (_tracking_level > NMT_off && _state == NMT_bootstrapping_single_thread) { // create nmt lock for multi-thread execution assert(_main_thread_tid == os::current_thread_id(), "wrong thread"); _state = NMT_bootstrapping_multi_thread; NMT_track_callsite = (_tracking_level == NMT_detail && can_walk_stack()); } } // fully start nmt void MemTracker::start() { // Native memory tracking is off from command line option if (_tracking_level == NMT_off || shutdown_in_progress()) return; assert(_main_thread_tid == os::current_thread_id(), "wrong thread"); assert(_state == NMT_bootstrapping_multi_thread, "wrong state"); _snapshot = new (std::nothrow)MemSnapshot(); if (_snapshot != NULL) { if (!_snapshot->out_of_memory() && start_worker()) { _state = NMT_started; NMT_track_callsite = (_tracking_level == NMT_detail && can_walk_stack()); return; } delete _snapshot; _snapshot = NULL; } // fail to start native memory tracking, shut it down shutdown(NMT_initialization); } /** * Shutting down native memory tracking. * We can not shutdown native memory tracking immediately, so we just * setup shutdown pending flag, every native memory tracking component * should orderly shut itself down. * * The shutdown sequences: * 1. MemTracker::shutdown() sets MemTracker to shutdown pending state * 2. Worker thread calls MemTracker::final_shutdown(), which transites * MemTracker to final shutdown state. * 3. At sync point, MemTracker does final cleanup, before sets memory * tracking level to off to complete shutdown. */ void MemTracker::shutdown(ShutdownReason reason) { if (_tracking_level == NMT_off) return; if (_state <= NMT_bootstrapping_single_thread) { // we still in single thread mode, there is not contention _state = NMT_shutdown_pending; _reason = reason; } else { // we want to know who initialized shutdown if ((jint)NMT_started == Atomic::cmpxchg((jint)NMT_shutdown_pending, (jint*)&_state, (jint)NMT_started)) { _reason = reason; } } } // final phase of shutdown void MemTracker::final_shutdown() { // delete all pending recorders and pooled recorders delete_all_pending_recorders(); delete_all_pooled_recorders(); { // shared baseline and snapshot are the only objects needed to // create query results MutexLockerEx locker(_query_lock, true); // cleanup baseline data and snapshot _baseline.clear(); delete _snapshot; _snapshot = NULL; } // shutdown shared decoder instance, since it is only // used by native memory tracking so far. Decoder::shutdown(); MemTrackWorker* worker = NULL; { ThreadCritical tc; // can not delete worker inside the thread critical if (_worker_thread != NULL && Thread::current() == _worker_thread) { worker = _worker_thread; _worker_thread = NULL; } } if (worker != NULL) { delete worker; } _state = NMT_final_shutdown; } // delete all pooled recorders void MemTracker::delete_all_pooled_recorders() { // free all pooled recorders volatile MemRecorder* cur_head = _pooled_recorders; if (cur_head != NULL) { MemRecorder* null_ptr = NULL; while (cur_head != NULL && (void*)cur_head != Atomic::cmpxchg_ptr((void*)null_ptr, (void*)&_pooled_recorders, (void*)cur_head)) { cur_head = _pooled_recorders; } if (cur_head != NULL) { delete cur_head; _pooled_recorder_count = 0; } } } // delete all recorders in pending queue void MemTracker::delete_all_pending_recorders() { // free all pending recorders MemRecorder* pending_head = get_pending_recorders(); if (pending_head != NULL) { delete pending_head; } } /* * retrieve per-thread recorder of specified thread. * if thread == NULL, it means global recorder */ MemRecorder* MemTracker::get_thread_recorder(JavaThread* thread) { if (shutdown_in_progress()) return NULL; MemRecorder* rc; if (thread == NULL) { rc = _global_recorder; } else { rc = thread->get_recorder(); } if (rc != NULL && rc->is_full()) { enqueue_pending_recorder(rc); rc = NULL; } if (rc == NULL) { rc = get_new_or_pooled_instance(); if (thread == NULL) { _global_recorder = rc; } else { thread->set_recorder(rc); } } return rc; } /* * get a per-thread recorder from pool, or create a new one if * there is not one available. */ MemRecorder* MemTracker::get_new_or_pooled_instance() { MemRecorder* cur_head = const_cast<MemRecorder*> (_pooled_recorders); if (cur_head == NULL) { MemRecorder* rec = new (std::nothrow)MemRecorder(); if (rec == NULL || rec->out_of_memory()) { shutdown(NMT_out_of_memory); if (rec != NULL) { delete rec; rec = NULL; } } return rec; } else { MemRecorder* next_head = cur_head->next(); if ((void*)cur_head != Atomic::cmpxchg_ptr((void*)next_head, (void*)&_pooled_recorders, (void*)cur_head)) { return get_new_or_pooled_instance(); } cur_head->set_next(NULL); Atomic::dec(&_pooled_recorder_count); cur_head->set_generation(); return cur_head; } } /* * retrieve all recorders in pending queue, and empty the queue */ MemRecorder* MemTracker::get_pending_recorders() { MemRecorder* cur_head = const_cast<MemRecorder*>(_merge_pending_queue); MemRecorder* null_ptr = NULL; while ((void*)cur_head != Atomic::cmpxchg_ptr((void*)null_ptr, (void*)&_merge_pending_queue, (void*)cur_head)) { cur_head = const_cast<MemRecorder*>(_merge_pending_queue); } NOT_PRODUCT(Atomic::store(0, &_pending_recorder_count)); return cur_head; } /* * release a recorder to recorder pool. */ void MemTracker::release_thread_recorder(MemRecorder* rec) { assert(rec != NULL, "null recorder"); // we don't want to pool too many recorders rec->set_next(NULL); if (shutdown_in_progress() || _pooled_recorder_count > _thread_count * 2) { delete rec; return; } rec->clear(); MemRecorder* cur_head = const_cast<MemRecorder*>(_pooled_recorders); rec->set_next(cur_head); while ((void*)cur_head != Atomic::cmpxchg_ptr((void*)rec, (void*)&_pooled_recorders, (void*)cur_head)) { cur_head = const_cast<MemRecorder*>(_pooled_recorders); rec->set_next(cur_head); } Atomic::inc(&_pooled_recorder_count); } /* * This is the most important method in whole nmt implementation. * * Create a memory record. * 1. When nmt is in single-threaded bootstrapping mode, no lock is needed as VM * still in single thread mode. * 2. For all threads other than JavaThread, ThreadCritical is needed * to write to recorders to global recorder. * 3. For JavaThreads that are not longer visible by safepoint, also * need to take ThreadCritical and records are written to global * recorders, since these threads are NOT walked by Threads.do_thread(). * 4. JavaThreads that are running in native state, have to transition * to VM state before writing to per-thread recorders. * 5. JavaThreads that are running in VM state do not need any lock and * records are written to per-thread recorders. * 6. For a thread has yet to attach VM 'Thread', they need to take * ThreadCritical to write to global recorder. * * Important note: * NO LOCK should be taken inside ThreadCritical lock !!! */ void MemTracker::create_memory_record(address addr, MEMFLAGS flags, size_t size, address pc, Thread* thread) { assert(addr != NULL, "Sanity check"); if (!shutdown_in_progress()) { // single thread, we just write records direct to global recorder,' // with any lock if (_state == NMT_bootstrapping_single_thread) { assert(_main_thread_tid == os::current_thread_id(), "wrong thread"); thread = NULL; } else { if (thread == NULL) { // don't use Thread::current(), since it is possible that // the calling thread has yet to attach to VM 'Thread', // which will result assertion failure thread = ThreadLocalStorage::thread(); } } if (thread != NULL) { // slow down all calling threads except NMT worker thread, so it // can catch up. if (_slowdown_calling_thread && thread != _worker_thread) { os::yield_all(); } if (thread->is_Java_thread() && ((JavaThread*)thread)->is_safepoint_visible()) { JavaThread* java_thread = (JavaThread*)thread; JavaThreadState state = java_thread->thread_state(); if (SafepointSynchronize::safepoint_safe(java_thread, state)) { // JavaThreads that are safepoint safe, can run through safepoint, // so ThreadCritical is needed to ensure no threads at safepoint create // new records while the records are being gathered and the sequence number is changing ThreadCritical tc; create_record_in_recorder(addr, flags, size, pc, java_thread); } else { create_record_in_recorder(addr, flags, size, pc, java_thread); } } else { // other threads, such as worker and watcher threads, etc. need to // take ThreadCritical to write to global recorder ThreadCritical tc; create_record_in_recorder(addr, flags, size, pc, NULL); } } else { if (_state == NMT_bootstrapping_single_thread) { // single thread, no lock needed create_record_in_recorder(addr, flags, size, pc, NULL); } else { // for thread has yet to attach VM 'Thread', we can not use VM mutex. // use native thread critical instead ThreadCritical tc; create_record_in_recorder(addr, flags, size, pc, NULL); } } } } // write a record to proper recorder. No lock can be taken from this method // down. void MemTracker::create_record_in_recorder(address addr, MEMFLAGS flags, size_t size, address pc, JavaThread* thread) { MemRecorder* rc = get_thread_recorder(thread); if (rc != NULL) { rc->record(addr, flags, size, pc); } } /** * enqueue a recorder to pending queue */ void MemTracker::enqueue_pending_recorder(MemRecorder* rec) { assert(rec != NULL, "null recorder"); // we are shutting down, so just delete it if (shutdown_in_progress()) { rec->set_next(NULL); delete rec; return; } MemRecorder* cur_head = const_cast<MemRecorder*>(_merge_pending_queue); rec->set_next(cur_head); while ((void*)cur_head != Atomic::cmpxchg_ptr((void*)rec, (void*)&_merge_pending_queue, (void*)cur_head)) { cur_head = const_cast<MemRecorder*>(_merge_pending_queue); rec->set_next(cur_head); } NOT_PRODUCT(Atomic::inc(&_pending_recorder_count);) } /* * The method is called at global safepoint * during it synchronization process. * 1. enqueue all JavaThreads' per-thread recorders * 2. enqueue global recorder * 3. retrieve all pending recorders * 4. reset global sequence number generator * 5. call worker's sync */ #define MAX_SAFEPOINTS_TO_SKIP 128 #define SAFE_SEQUENCE_THRESHOLD 30 #define HIGH_GENERATION_THRESHOLD 60 #define MAX_RECORDER_THREAD_RATIO 30 void MemTracker::sync() { assert(_tracking_level > NMT_off, "NMT is not enabled"); assert(SafepointSynchronize::is_at_safepoint(), "Safepoint required"); // Some GC tests hit large number of safepoints in short period of time // without meaningful activities. We should prevent going to // sync point in these cases, which can potentially exhaust generation buffer. // Here is the factots to determine if we should go into sync point: // 1. not to overflow sequence number // 2. if we are in danger to overflow generation buffer // 3. how many safepoints we already skipped sync point if (_state == NMT_started) { // worker thread is not ready, no one can manage generation // buffer, so skip this safepoint if (_worker_thread == NULL) return; if (_sync_point_skip_count < MAX_SAFEPOINTS_TO_SKIP) { int per_seq_in_use = SequenceGenerator::peek() * 100 / max_jint; int per_gen_in_use = _worker_thread->generations_in_use() * 100 / MAX_GENERATIONS; if (per_seq_in_use < SAFE_SEQUENCE_THRESHOLD && per_gen_in_use >= HIGH_GENERATION_THRESHOLD) { _sync_point_skip_count ++; return; } } _sync_point_skip_count = 0; { // This method is running at safepoint, with ThreadCritical lock, // it should guarantee that NMT is fully sync-ed. ThreadCritical tc; SequenceGenerator::reset(); // walk all JavaThreads to collect recorders SyncThreadRecorderClosure stc; Threads::threads_do(&stc); _thread_count = stc.get_thread_count(); MemRecorder* pending_recorders = get_pending_recorders(); if (_global_recorder != NULL) { _global_recorder->set_next(pending_recorders); pending_recorders = _global_recorder; _global_recorder = NULL; } // see if NMT has too many outstanding recorder instances, it usually // means that worker thread is lagging behind in processing them. if (!AutoShutdownNMT) { _slowdown_calling_thread = (MemRecorder::_instance_count > MAX_RECORDER_THREAD_RATIO * _thread_count); } // check _worker_thread with lock to avoid racing condition if (_worker_thread != NULL) { _worker_thread->at_sync_point(pending_recorders, InstanceKlass::number_of_instance_classes()); } assert(SequenceGenerator::peek() == 1, "Should not have memory activities during sync-point"); } } // now, it is the time to shut whole things off if (_state == NMT_final_shutdown) { // walk all JavaThreads to delete all recorders SyncThreadRecorderClosure stc; Threads::threads_do(&stc); // delete global recorder { ThreadCritical tc; if (_global_recorder != NULL) { delete _global_recorder; _global_recorder = NULL; } } MemRecorder* pending_recorders = get_pending_recorders(); if (pending_recorders != NULL) { delete pending_recorders; } // try at a later sync point to ensure MemRecorder instance drops to zero to // completely shutdown NMT if (MemRecorder::_instance_count == 0) { _state = NMT_shutdown; _tracking_level = NMT_off; } } } /* * Start worker thread. */ bool MemTracker::start_worker() { assert(_worker_thread == NULL, "Just Check"); _worker_thread = new (std::nothrow) MemTrackWorker(); if (_worker_thread == NULL || _worker_thread->has_error()) { if (_worker_thread != NULL) { delete _worker_thread; _worker_thread = NULL; } return false; } _worker_thread->start(); return true; } /* * We need to collect a JavaThread's per-thread recorder * before it exits. */ void MemTracker::thread_exiting(JavaThread* thread) { if (is_on()) { MemRecorder* rec = thread->get_recorder(); if (rec != NULL) { enqueue_pending_recorder(rec); thread->set_recorder(NULL); } } } // baseline current memory snapshot bool MemTracker::baseline() { MutexLockerEx lock(_query_lock, true); MemSnapshot* snapshot = get_snapshot(); if (snapshot != NULL) { return _baseline.baseline(*snapshot, false); } return false; } // print memory usage from current snapshot bool MemTracker::print_memory_usage(BaselineOutputer& out, size_t unit, bool summary_only) { MemBaseline baseline; MutexLockerEx lock(_query_lock, true); MemSnapshot* snapshot = get_snapshot(); if (snapshot != NULL && baseline.baseline(*snapshot, summary_only)) { BaselineReporter reporter(out, unit); reporter.report_baseline(baseline, summary_only); return true; } return false; } // Whitebox API for blocking until the current generation of NMT data has been merged bool MemTracker::wbtest_wait_for_data_merge() { // NMT can't be shutdown while we're holding _query_lock MutexLockerEx lock(_query_lock, true); assert(_worker_thread != NULL, "Invalid query"); // the generation at query time, so NMT will spin till this generation is processed unsigned long generation_at_query_time = SequenceGenerator::current_generation(); unsigned long current_processing_generation = _processing_generation; // if generation counter overflown bool generation_overflown = (generation_at_query_time < current_processing_generation); long generations_to_wrap = MAX_UNSIGNED_LONG - current_processing_generation; // spin while (!shutdown_in_progress()) { if (!generation_overflown) { if (current_processing_generation > generation_at_query_time) { return true; } } else { assert(generations_to_wrap >= 0, "Sanity check"); long current_generations_to_wrap = MAX_UNSIGNED_LONG - current_processing_generation; assert(current_generations_to_wrap >= 0, "Sanity check"); // to overflow an unsigned long should take long time, so to_wrap check should be sufficient if (current_generations_to_wrap > generations_to_wrap && current_processing_generation > generation_at_query_time) { return true; } } // if worker thread is idle, but generation is not advancing, that means // there is not safepoint to let NMT advance generation, force one. if (_worker_thread_idle) { VM_ForceSafepoint vfs; VMThread::execute(&vfs); } MemSnapshot* snapshot = get_snapshot(); if (snapshot == NULL) { return false; } snapshot->wait(1000); current_processing_generation = _processing_generation; } // We end up here if NMT is shutting down before our data has been merged return false; } // compare memory usage between current snapshot and baseline bool MemTracker::compare_memory_usage(BaselineOutputer& out, size_t unit, bool summary_only) { MutexLockerEx lock(_query_lock, true); if (_baseline.baselined()) { MemBaseline baseline; MemSnapshot* snapshot = get_snapshot(); if (snapshot != NULL && baseline.baseline(*snapshot, summary_only)) { BaselineReporter reporter(out, unit); reporter.diff_baselines(baseline, _baseline, summary_only); return true; } } return false; } #ifndef PRODUCT void MemTracker::walk_stack(int toSkip, char* buf, int len) { int cur_len = 0; char tmp[1024]; address pc; while (cur_len < len) { pc = os::get_caller_pc(toSkip + 1); if (pc != NULL && os::dll_address_to_function_name(pc, tmp, sizeof(tmp), NULL)) { jio_snprintf(&buf[cur_len], (len - cur_len), "%s\n", tmp); cur_len = (int)strlen(buf); } else { buf[cur_len] = '\0'; break; } toSkip ++; } } void MemTracker::print_tracker_stats(outputStream* st) { st->print_cr("\nMemory Tracker Stats:"); st->print_cr("\tMax sequence number = %d", SequenceGenerator::max_seq_num()); st->print_cr("\tthead count = %d", _thread_count); st->print_cr("\tArena instance = %d", Arena::_instance_count); st->print_cr("\tpooled recorder count = %d", _pooled_recorder_count); st->print_cr("\tqueued recorder count = %d", _pending_recorder_count); st->print_cr("\tmemory recorder instance count = %d", MemRecorder::_instance_count); if (_worker_thread != NULL) { st->print_cr("\tWorker thread:"); st->print_cr("\t\tSync point count = %d", _worker_thread->_sync_point_count); st->print_cr("\t\tpending recorder count = %d", _worker_thread->count_pending_recorders()); st->print_cr("\t\tmerge count = %d", _worker_thread->_merge_count); } else { st->print_cr("\tWorker thread is not started"); } st->print_cr(" "); if (_snapshot != NULL) { _snapshot->print_snapshot_stats(st); } else { st->print_cr("No snapshot"); } } #endif