# HG changeset patch # User stefank # Date 1363980729 25200 # Node ID 50adbbdd499e64baa5fc1c6abe47881dd47b9fc0 # Parent 6f0d2de1c5694250af9854864ad0741a2ea51927# Parent 07535395a6006b46901c8be17b0f760bedb22224 Merge diff -r 6f0d2de1c569 -r 50adbbdd499e hotspot/src/share/vm/gc_implementation/concurrentMarkSweep/concurrentMarkSweepGeneration.cpp --- a/hotspot/src/share/vm/gc_implementation/concurrentMarkSweep/concurrentMarkSweepGeneration.cpp Thu Mar 21 21:48:56 2013 -0700 +++ b/hotspot/src/share/vm/gc_implementation/concurrentMarkSweep/concurrentMarkSweepGeneration.cpp Fri Mar 22 12:32:09 2013 -0700 @@ -6068,6 +6068,10 @@ verify_work_stacks_empty(); verify_overflow_empty(); + if (should_unload_classes()) { + ClassLoaderDataGraph::purge(); + } + _intra_sweep_timer.stop(); _intra_sweep_estimate.sample(_intra_sweep_timer.seconds()); diff -r 6f0d2de1c569 -r 50adbbdd499e hotspot/src/share/vm/gc_implementation/g1/concurrentMark.cpp --- a/hotspot/src/share/vm/gc_implementation/g1/concurrentMark.cpp Thu Mar 21 21:48:56 2013 -0700 +++ b/hotspot/src/share/vm/gc_implementation/g1/concurrentMark.cpp Fri Mar 22 12:32:09 2013 -0700 @@ -784,7 +784,7 @@ } } -void ConcurrentMark::set_phase(uint active_tasks, bool concurrent) { +void ConcurrentMark::set_concurrency(uint active_tasks) { assert(active_tasks <= _max_worker_id, "we should not have more"); _active_tasks = active_tasks; @@ -793,6 +793,10 @@ _terminator = ParallelTaskTerminator((int) active_tasks, _task_queues); _first_overflow_barrier_sync.set_n_workers((int) active_tasks); _second_overflow_barrier_sync.set_n_workers((int) active_tasks); +} + +void ConcurrentMark::set_concurrency_and_phase(uint active_tasks, bool concurrent) { + set_concurrency(active_tasks); _concurrent = concurrent; // We propagate this to all tasks, not just the active ones. @@ -806,7 +810,9 @@ // false before we start remark. At this point we should also be // in a STW phase. assert(!concurrent_marking_in_progress(), "invariant"); - assert(_finger == _heap_end, "only way to get here"); + assert(_finger == _heap_end, + err_msg("only way to get here: _finger: "PTR_FORMAT", _heap_end: "PTR_FORMAT, + _finger, _heap_end)); update_g1_committed(true); } } @@ -974,20 +980,28 @@ gclog_or_tty->print_cr("[%u] leaving first barrier", worker_id); } - // let the task associated with with worker 0 do this - if (worker_id == 0) { - // task 0 is responsible for clearing the global data structures - // We should be here because of an overflow. During STW we should - // not clear the overflow flag since we rely on it being true when - // we exit this method to abort the pause and restart concurent - // marking. - reset_marking_state(concurrent() /* clear_overflow */); - force_overflow()->update(); - - if (G1Log::fine()) { - gclog_or_tty->date_stamp(PrintGCDateStamps); - gclog_or_tty->stamp(PrintGCTimeStamps); - gclog_or_tty->print_cr("[GC concurrent-mark-reset-for-overflow]"); + // If we're executing the concurrent phase of marking, reset the marking + // state; otherwise the marking state is reset after reference processing, + // during the remark pause. + // If we reset here as a result of an overflow during the remark we will + // see assertion failures from any subsequent set_concurrency_and_phase() + // calls. + if (concurrent()) { + // let the task associated with with worker 0 do this + if (worker_id == 0) { + // task 0 is responsible for clearing the global data structures + // We should be here because of an overflow. During STW we should + // not clear the overflow flag since we rely on it being true when + // we exit this method to abort the pause and restart concurent + // marking. + reset_marking_state(true /* clear_overflow */); + force_overflow()->update(); + + if (G1Log::fine()) { + gclog_or_tty->date_stamp(PrintGCDateStamps); + gclog_or_tty->stamp(PrintGCTimeStamps); + gclog_or_tty->print_cr("[GC concurrent-mark-reset-for-overflow]"); + } } } @@ -1007,7 +1021,7 @@ if (concurrent()) { ConcurrentGCThread::stsJoin(); } - // at this point everything should be re-initialised and ready to go + // at this point everything should be re-initialized and ready to go if (verbose_low()) { gclog_or_tty->print_cr("[%u] leaving second barrier", worker_id); @@ -1065,8 +1079,8 @@ double mark_step_duration_ms = G1ConcMarkStepDurationMillis; the_task->do_marking_step(mark_step_duration_ms, - true /* do_stealing */, - true /* do_termination */); + true /* do_termination */, + false /* is_serial*/); double end_time_sec = os::elapsedTime(); double end_vtime_sec = os::elapsedVTime(); @@ -1222,8 +1236,8 @@ uint active_workers = MAX2(1U, parallel_marking_threads()); - // Parallel task terminator is set in "set_phase()" - set_phase(active_workers, true /* concurrent */); + // Parallel task terminator is set in "set_concurrency_and_phase()" + set_concurrency_and_phase(active_workers, true /* concurrent */); CMConcurrentMarkingTask markingTask(this, cmThread()); if (use_parallel_marking_threads()) { @@ -1275,12 +1289,22 @@ if (has_overflown()) { // Oops. We overflowed. Restart concurrent marking. _restart_for_overflow = true; + if (G1TraceMarkStackOverflow) { + gclog_or_tty->print_cr("\nRemark led to restart for overflow."); + } + + // Verify the heap w.r.t. the previous marking bitmap. + if (VerifyDuringGC) { + HandleMark hm; // handle scope + gclog_or_tty->print(" VerifyDuringGC:(overflow)"); + Universe::heap()->prepare_for_verify(); + Universe::verify(/* silent */ false, + /* option */ VerifyOption_G1UsePrevMarking); + } + // Clear the marking state because we will be restarting // marking due to overflowing the global mark stack. reset_marking_state(); - if (G1TraceMarkStackOverflow) { - gclog_or_tty->print_cr("\nRemark led to restart for overflow."); - } } else { // Aggregate the per-task counting data that we have accumulated // while marking. @@ -2184,14 +2208,17 @@ // operating on the global stack. class G1CMKeepAliveAndDrainClosure: public OopClosure { - ConcurrentMark* _cm; - CMTask* _task; - int _ref_counter_limit; - int _ref_counter; + ConcurrentMark* _cm; + CMTask* _task; + int _ref_counter_limit; + int _ref_counter; + bool _is_serial; public: - G1CMKeepAliveAndDrainClosure(ConcurrentMark* cm, CMTask* task) : - _cm(cm), _task(task), _ref_counter_limit(G1RefProcDrainInterval) { + G1CMKeepAliveAndDrainClosure(ConcurrentMark* cm, CMTask* task, bool is_serial) : + _cm(cm), _task(task), _is_serial(is_serial), + _ref_counter_limit(G1RefProcDrainInterval) { assert(_ref_counter_limit > 0, "sanity"); + assert(!_is_serial || _task->worker_id() == 0, "only task 0 for serial code"); _ref_counter = _ref_counter_limit; } @@ -2230,8 +2257,8 @@ do { double mark_step_duration_ms = G1ConcMarkStepDurationMillis; _task->do_marking_step(mark_step_duration_ms, - false /* do_stealing */, - false /* do_termination */); + false /* do_termination */, + _is_serial); } while (_task->has_aborted() && !_cm->has_overflown()); _ref_counter = _ref_counter_limit; } @@ -2253,27 +2280,18 @@ class G1CMDrainMarkingStackClosure: public VoidClosure { ConcurrentMark* _cm; CMTask* _task; - bool _do_stealing; - bool _do_termination; + bool _is_serial; public: - G1CMDrainMarkingStackClosure(ConcurrentMark* cm, CMTask* task, bool is_par) : - _cm(cm), _task(task) { - assert(is_par || _task->worker_id() == 0, - "Only task for worker 0 should be used if ref processing is single threaded"); - // We only allow stealing and only enter the termination protocol - // in CMTask::do_marking_step() if this closure is being instantiated - // for parallel reference processing. - _do_stealing = _do_termination = is_par; + G1CMDrainMarkingStackClosure(ConcurrentMark* cm, CMTask* task, bool is_serial) : + _cm(cm), _task(task), _is_serial(is_serial) { + assert(!_is_serial || _task->worker_id() == 0, "only task 0 for serial code"); } void do_void() { do { if (_cm->verbose_high()) { - gclog_or_tty->print_cr("\t[%u] Drain: Calling do_marking_step - " - "stealing: %s, termination: %s", - _task->worker_id(), - BOOL_TO_STR(_do_stealing), - BOOL_TO_STR(_do_termination)); + gclog_or_tty->print_cr("\t[%u] Drain: Calling do_marking_step - serial: %s", + _task->worker_id(), BOOL_TO_STR(_is_serial)); } // We call CMTask::do_marking_step() to completely drain the local @@ -2294,8 +2312,8 @@ // has_aborted() flag that the marking step has completed. _task->do_marking_step(1000000000.0 /* something very large */, - _do_stealing, - _do_termination); + true /* do_termination */, + _is_serial); } while (_task->has_aborted() && !_cm->has_overflown()); } }; @@ -2328,7 +2346,6 @@ ProcessTask& _proc_task; G1CollectedHeap* _g1h; ConcurrentMark* _cm; - bool _processing_is_mt; public: G1CMRefProcTaskProxy(ProcessTask& proc_task, @@ -2336,15 +2353,15 @@ ConcurrentMark* cm) : AbstractGangTask("Process reference objects in parallel"), _proc_task(proc_task), _g1h(g1h), _cm(cm) { - ReferenceProcessor* rp = _g1h->ref_processor_cm(); - _processing_is_mt = rp->processing_is_mt(); - } + ReferenceProcessor* rp = _g1h->ref_processor_cm(); + assert(rp->processing_is_mt(), "shouldn't be here otherwise"); + } virtual void work(uint worker_id) { - CMTask* marking_task = _cm->task(worker_id); + CMTask* task = _cm->task(worker_id); G1CMIsAliveClosure g1_is_alive(_g1h); - G1CMKeepAliveAndDrainClosure g1_par_keep_alive(_cm, marking_task); - G1CMDrainMarkingStackClosure g1_par_drain(_cm, marking_task, _processing_is_mt); + G1CMKeepAliveAndDrainClosure g1_par_keep_alive(_cm, task, false /* is_serial */); + G1CMDrainMarkingStackClosure g1_par_drain(_cm, task, false /* is_serial */); _proc_task.work(worker_id, g1_is_alive, g1_par_keep_alive, g1_par_drain); } @@ -2356,9 +2373,11 @@ G1CMRefProcTaskProxy proc_task_proxy(proc_task, _g1h, _cm); - // We need to reset the phase for each task execution so that - // the termination protocol of CMTask::do_marking_step works. - _cm->set_phase(_active_workers, false /* concurrent */); + // We need to reset the concurrency level before each + // proxy task execution, so that the termination protocol + // and overflow handling in CMTask::do_marking_step() knows + // how many workers to wait for. + _cm->set_concurrency(_active_workers); _g1h->set_par_threads(_active_workers); _workers->run_task(&proc_task_proxy); _g1h->set_par_threads(0); @@ -2384,12 +2403,29 @@ G1CMRefEnqueueTaskProxy enq_task_proxy(enq_task); + // Not strictly necessary but... + // + // We need to reset the concurrency level before each + // proxy task execution, so that the termination protocol + // and overflow handling in CMTask::do_marking_step() knows + // how many workers to wait for. + _cm->set_concurrency(_active_workers); _g1h->set_par_threads(_active_workers); _workers->run_task(&enq_task_proxy); _g1h->set_par_threads(0); } void ConcurrentMark::weakRefsWork(bool clear_all_soft_refs) { + if (has_overflown()) { + // Skip processing the discovered references if we have + // overflown the global marking stack. Reference objects + // only get discovered once so it is OK to not + // de-populate the discovered reference lists. We could have, + // but the only benefit would be that, when marking restarts, + // less reference objects are discovered. + return; + } + ResourceMark rm; HandleMark hm; @@ -2415,26 +2451,39 @@ rp->setup_policy(clear_all_soft_refs); assert(_markStack.isEmpty(), "mark stack should be empty"); - // Non-MT instances 'Keep Alive' and 'Complete GC' oop closures. - G1CMKeepAliveAndDrainClosure g1_keep_alive(this, task(0)); - G1CMDrainMarkingStackClosure g1_drain_mark_stack(this, task(0), false); - - // We need at least one active thread. If reference processing is - // not multi-threaded we use the current (ConcurrentMarkThread) thread, - // otherwise we use the work gang from the G1CollectedHeap and we - // utilize all the worker threads we can. - uint active_workers = (rp->processing_is_mt() && g1h->workers() != NULL - ? g1h->workers()->active_workers() - : 1U); - + // Instances of the 'Keep Alive' and 'Complete GC' closures used + // in serial reference processing. Note these closures are also + // used for serially processing (by the the current thread) the + // JNI references during parallel reference processing. + // + // These closures do not need to synchronize with the worker + // threads involved in parallel reference processing as these + // instances are executed serially by the current thread (e.g. + // reference processing is not multi-threaded and is thus + // performed by the current thread instead of a gang worker). + // + // The gang tasks involved in parallel reference procssing create + // their own instances of these closures, which do their own + // synchronization among themselves. + G1CMKeepAliveAndDrainClosure g1_keep_alive(this, task(0), true /* is_serial */); + G1CMDrainMarkingStackClosure g1_drain_mark_stack(this, task(0), true /* is_serial */); + + // We need at least one active thread. If reference processing + // is not multi-threaded we use the current (VMThread) thread, + // otherwise we use the work gang from the G1CollectedHeap and + // we utilize all the worker threads we can. + bool processing_is_mt = rp->processing_is_mt() && g1h->workers() != NULL; + uint active_workers = (processing_is_mt ? g1h->workers()->active_workers() : 1U); active_workers = MAX2(MIN2(active_workers, _max_worker_id), 1U); + // Parallel processing task executor. G1CMRefProcTaskExecutor par_task_executor(g1h, this, g1h->workers(), active_workers); - - AbstractRefProcTaskExecutor* executor = (rp->processing_is_mt() - ? &par_task_executor - : NULL); + AbstractRefProcTaskExecutor* executor = (processing_is_mt ? &par_task_executor : NULL); + + // Set the concurrency level. The phase was already set prior to + // executing the remark task. + set_concurrency(active_workers); // Set the degree of MT processing here. If the discovery was done MT, // the number of threads involved during discovery could differ from @@ -2454,6 +2503,7 @@ assert(_markStack.overflow() || _markStack.isEmpty(), "mark stack should be empty (unless it overflowed)"); + if (_markStack.overflow()) { // This should have been done already when we tried to push an // entry on to the global mark stack. But let's do it again. @@ -2482,8 +2532,8 @@ class CMRemarkTask: public AbstractGangTask { private: - ConcurrentMark *_cm; - + ConcurrentMark* _cm; + bool _is_serial; public: void work(uint worker_id) { // Since all available tasks are actually started, we should @@ -2493,8 +2543,8 @@ task->record_start_time(); do { task->do_marking_step(1000000000.0 /* something very large */, - true /* do_stealing */, - true /* do_termination */); + true /* do_termination */, + _is_serial); } while (task->has_aborted() && !_cm->has_overflown()); // If we overflow, then we do not want to restart. We instead // want to abort remark and do concurrent marking again. @@ -2502,8 +2552,8 @@ } } - CMRemarkTask(ConcurrentMark* cm, int active_workers) : - AbstractGangTask("Par Remark"), _cm(cm) { + CMRemarkTask(ConcurrentMark* cm, int active_workers, bool is_serial) : + AbstractGangTask("Par Remark"), _cm(cm), _is_serial(is_serial) { _cm->terminator()->reset_for_reuse(active_workers); } }; @@ -2524,30 +2574,40 @@ active_workers = (uint) ParallelGCThreads; g1h->workers()->set_active_workers(active_workers); } - set_phase(active_workers, false /* concurrent */); + set_concurrency_and_phase(active_workers, false /* concurrent */); // Leave _parallel_marking_threads at it's // value originally calculated in the ConcurrentMark // constructor and pass values of the active workers // through the gang in the task. - CMRemarkTask remarkTask(this, active_workers); + CMRemarkTask remarkTask(this, active_workers, false /* is_serial */); + // We will start all available threads, even if we decide that the + // active_workers will be fewer. The extra ones will just bail out + // immediately. g1h->set_par_threads(active_workers); g1h->workers()->run_task(&remarkTask); g1h->set_par_threads(0); } else { G1CollectedHeap::StrongRootsScope srs(g1h); - // this is remark, so we'll use up all available threads uint active_workers = 1; - set_phase(active_workers, false /* concurrent */); - - CMRemarkTask remarkTask(this, active_workers); - // We will start all available threads, even if we decide that the - // active_workers will be fewer. The extra ones will just bail out - // immediately. + set_concurrency_and_phase(active_workers, false /* concurrent */); + + // Note - if there's no work gang then the VMThread will be + // the thread to execute the remark - serially. We have + // to pass true for the is_serial parameter so that + // CMTask::do_marking_step() doesn't enter the sync + // barriers in the event of an overflow. Doing so will + // cause an assert that the current thread is not a + // concurrent GC thread. + CMRemarkTask remarkTask(this, active_workers, true /* is_serial*/); remarkTask.work(0); } SATBMarkQueueSet& satb_mq_set = JavaThread::satb_mark_queue_set(); - guarantee(satb_mq_set.completed_buffers_num() == 0, "invariant"); + guarantee(has_overflown() || + satb_mq_set.completed_buffers_num() == 0, + err_msg("Invariant: has_overflown = %s, num buffers = %d", + BOOL_TO_STR(has_overflown()), + satb_mq_set.completed_buffers_num())); print_stats(); } @@ -3854,8 +3914,8 @@ /***************************************************************************** - The do_marking_step(time_target_ms) method is the building block - of the parallel marking framework. It can be called in parallel + The do_marking_step(time_target_ms, ...) method is the building + block of the parallel marking framework. It can be called in parallel with other invocations of do_marking_step() on different tasks (but only one per task, obviously) and concurrently with the mutator threads, or during remark, hence it eliminates the need @@ -3865,7 +3925,7 @@ pauses too, since do_marking_step() ensures that it aborts before it needs to yield. - The data structures that is uses to do marking work are the + The data structures that it uses to do marking work are the following: (1) Marking Bitmap. If there are gray objects that appear only @@ -3914,7 +3974,7 @@ (2) When a global overflow (on the global stack) has been triggered. Before the task aborts, it will actually sync up with the other tasks to ensure that all the marking data structures - (local queues, stacks, fingers etc.) are re-initialised so that + (local queues, stacks, fingers etc.) are re-initialized so that when do_marking_step() completes, the marking phase can immediately restart. @@ -3951,11 +4011,25 @@ place, it was natural to piggy-back all the other conditions on it too and not constantly check them throughout the code. + If do_termination is true then do_marking_step will enter its + termination protocol. + + The value of is_serial must be true when do_marking_step is being + called serially (i.e. by the VMThread) and do_marking_step should + skip any synchronization in the termination and overflow code. + Examples include the serial remark code and the serial reference + processing closures. + + The value of is_serial must be false when do_marking_step is + being called by any of the worker threads in a work gang. + Examples include the concurrent marking code (CMMarkingTask), + the MT remark code, and the MT reference processing closures. + *****************************************************************************/ void CMTask::do_marking_step(double time_target_ms, - bool do_stealing, - bool do_termination) { + bool do_termination, + bool is_serial) { assert(time_target_ms >= 1.0, "minimum granularity is 1ms"); assert(concurrent() == _cm->concurrent(), "they should be the same"); @@ -3976,6 +4050,12 @@ _start_time_ms = os::elapsedVTime() * 1000.0; statsOnly( _interval_start_time_ms = _start_time_ms ); + // If do_stealing is true then do_marking_step will attempt to + // steal work from the other CMTasks. It only makes sense to + // enable stealing when the termination protocol is enabled + // and do_marking_step() is not being called serially. + bool do_stealing = do_termination && !is_serial; + double diff_prediction_ms = g1_policy->get_new_prediction(&_marking_step_diffs_ms); _time_target_ms = time_target_ms - diff_prediction_ms; @@ -4237,10 +4317,12 @@ } _termination_start_time_ms = os::elapsedVTime() * 1000.0; + // The CMTask class also extends the TerminatorTerminator class, // hence its should_exit_termination() method will also decide // whether to exit the termination protocol or not. - bool finished = _cm->terminator()->offer_termination(this); + bool finished = (is_serial || + _cm->terminator()->offer_termination(this)); double termination_end_time_ms = os::elapsedVTime() * 1000.0; _termination_time_ms += termination_end_time_ms - _termination_start_time_ms; @@ -4320,20 +4402,28 @@ gclog_or_tty->print_cr("[%u] detected overflow", _worker_id); } - _cm->enter_first_sync_barrier(_worker_id); - // When we exit this sync barrier we know that all tasks have - // stopped doing marking work. So, it's now safe to - // re-initialise our data structures. At the end of this method, - // task 0 will clear the global data structures. + if (!is_serial) { + // We only need to enter the sync barrier if being called + // from a parallel context + _cm->enter_first_sync_barrier(_worker_id); + + // When we exit this sync barrier we know that all tasks have + // stopped doing marking work. So, it's now safe to + // re-initialise our data structures. At the end of this method, + // task 0 will clear the global data structures. + } statsOnly( ++_aborted_overflow ); // We clear the local state of this task... clear_region_fields(); - // ...and enter the second barrier. - _cm->enter_second_sync_barrier(_worker_id); - // At this point everything has bee re-initialised and we're + if (!is_serial) { + // ...and enter the second barrier. + _cm->enter_second_sync_barrier(_worker_id); + } + // At this point, if we're during the concurrent phase of + // marking, everything has been re-initialized and we're // ready to restart. } diff -r 6f0d2de1c569 -r 50adbbdd499e hotspot/src/share/vm/gc_implementation/g1/concurrentMark.hpp --- a/hotspot/src/share/vm/gc_implementation/g1/concurrentMark.hpp Thu Mar 21 21:48:56 2013 -0700 +++ b/hotspot/src/share/vm/gc_implementation/g1/concurrentMark.hpp Fri Mar 22 12:32:09 2013 -0700 @@ -166,7 +166,7 @@ class CMMarkStack VALUE_OBJ_CLASS_SPEC { VirtualSpace _virtual_space; // Underlying backing store for actual stack ConcurrentMark* _cm; - oop* _base; // bottom of stack + oop* _base; // bottom of stack jint _index; // one more than last occupied index jint _capacity; // max #elements jint _saved_index; // value of _index saved at start of GC @@ -491,9 +491,12 @@ // structures are initialised to a sensible and predictable state. void set_non_marking_state(); + // Called to indicate how many threads are currently active. + void set_concurrency(uint active_tasks); + // It should be called to indicate which phase we're in (concurrent // mark or remark) and how many threads are currently active. - void set_phase(uint active_tasks, bool concurrent); + void set_concurrency_and_phase(uint active_tasks, bool concurrent); // prints all gathered CM-related statistics void print_stats(); @@ -1146,7 +1149,9 @@ // trying not to exceed the given duration. However, it might exit // prematurely, according to some conditions (i.e. SATB buffers are // available for processing). - void do_marking_step(double target_ms, bool do_stealing, bool do_termination); + void do_marking_step(double target_ms, + bool do_termination, + bool is_serial); // These two calls start and stop the timer void record_start_time() { diff -r 6f0d2de1c569 -r 50adbbdd499e hotspot/src/share/vm/gc_implementation/parallelScavenge/parallelScavengeHeap.cpp --- a/hotspot/src/share/vm/gc_implementation/parallelScavenge/parallelScavengeHeap.cpp Thu Mar 21 21:48:56 2013 -0700 +++ b/hotspot/src/share/vm/gc_implementation/parallelScavenge/parallelScavengeHeap.cpp Fri Mar 22 12:32:09 2013 -0700 @@ -656,7 +656,7 @@ tty->print_cr("[Accumulated GC generation 0 time %3.7f secs]", time); } if (TraceGen1Time) { - double time = PSMarkSweep::accumulated_time()->seconds(); + double time = UseParallelOldGC ? PSParallelCompact::accumulated_time()->seconds() : PSMarkSweep::accumulated_time()->seconds(); tty->print_cr("[Accumulated GC generation 1 time %3.7f secs]", time); } } diff -r 6f0d2de1c569 -r 50adbbdd499e hotspot/src/share/vm/memory/genCollectedHeap.cpp --- a/hotspot/src/share/vm/memory/genCollectedHeap.cpp Thu Mar 21 21:48:56 2013 -0700 +++ b/hotspot/src/share/vm/memory/genCollectedHeap.cpp Fri Mar 22 12:32:09 2013 -0700 @@ -554,6 +554,8 @@ } if (complete) { + // Delete metaspaces for unloaded class loaders and clean up loader_data graph + ClassLoaderDataGraph::purge(); // Resize the metaspace capacity after full collections MetaspaceGC::compute_new_size(); update_full_collections_completed(); @@ -564,11 +566,6 @@ gc_epilogue(complete); - // Delete metaspaces for unloaded class loaders and clean up loader_data graph - if (complete) { - ClassLoaderDataGraph::purge(); - } - if (must_restore_marks_for_biased_locking) { BiasedLocking::restore_marks(); } diff -r 6f0d2de1c569 -r 50adbbdd499e hotspot/src/share/vm/memory/metaspace.cpp --- a/hotspot/src/share/vm/memory/metaspace.cpp Thu Mar 21 21:48:56 2013 -0700 +++ b/hotspot/src/share/vm/memory/metaspace.cpp Fri Mar 22 12:32:09 2013 -0700 @@ -1103,25 +1103,24 @@ } bool MetaspaceGC::should_expand(VirtualSpaceList* vsl, size_t word_size) { + // If the user wants a limit, impose one. + if (!FLAG_IS_DEFAULT(MaxMetaspaceSize) && + MetaspaceAux::reserved_in_bytes() >= MaxMetaspaceSize) { + return false; + } // Class virtual space should always be expanded. Call GC for the other // metadata virtual space. if (vsl == Metaspace::class_space_list()) return true; - // If the user wants a limit, impose one. - size_t max_metaspace_size_words = MaxMetaspaceSize / BytesPerWord; - size_t metaspace_size_words = MetaspaceSize / BytesPerWord; - if (!FLAG_IS_DEFAULT(MaxMetaspaceSize) && - vsl->capacity_words_sum() >= max_metaspace_size_words) { - return false; - } - // If this is part of an allocation after a GC, expand // unconditionally. if(MetaspaceGC::expand_after_GC()) { return true; } + size_t metaspace_size_words = MetaspaceSize / BytesPerWord; + // If the capacity is below the minimum capacity, allow the // expansion. Also set the high-water-mark (capacity_until_GC) // to that minimum capacity so that a GC will not be induced @@ -1311,8 +1310,7 @@ gclog_or_tty->print_cr(" metaspace HWM: %.1fK", new_capacity_until_GC / (double) K); } } - assert(vsl->used_bytes_sum() == used_after_gc && - used_after_gc <= vsl->capacity_bytes_sum(), + assert(used_after_gc <= vsl->capacity_bytes_sum(), "sanity check"); } @@ -1972,6 +1970,9 @@ } SpaceManager::~SpaceManager() { + // This call this->_lock which can't be done while holding expand_lock() + const size_t in_use_before = sum_capacity_in_chunks_in_use(); + MutexLockerEx fcl(SpaceManager::expand_lock(), Mutex::_no_safepoint_check_flag); @@ -1989,7 +1990,7 @@ // Have to update before the chunks_in_use lists are emptied // below. - chunk_manager->inc_free_chunks_total(sum_capacity_in_chunks_in_use(), + chunk_manager->inc_free_chunks_total(in_use_before, sum_count_in_chunks_in_use()); // Add all the chunks in use by this space manager