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src/share/vm/memory/threadLocalAllocBuffer.cpp@de88570fabfc (annotated)

src/share/vm/memory/threadLocalAllocBuffer.cpp

Wed, 11 Sep 2013 00:38:18 -0400

author

dholmes

date

Wed, 11 Sep 2013 00:38:18 -0400

changeset 5689

de88570fabfc

parent 4299

f34d701e952e

child 6376

cfd4aac53239

permissions

-rw-r--r--

8024256: Minimal VM build is broken with PCH disabled
Reviewed-by: coleenp, twisti

duke@435	1	/*
phh@2423	2	* Copyright (c) 1999, 2011, Oracle and/or its affiliates. All rights reserved.
duke@435	3	* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
duke@435	4	*
duke@435	5	* This code is free software; you can redistribute it and/or modify it
duke@435	6	* under the terms of the GNU General Public License version 2 only, as
duke@435	7	* published by the Free Software Foundation.
duke@435	8	*
duke@435	9	* This code is distributed in the hope that it will be useful, but WITHOUT
duke@435	10	* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
duke@435	11	* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
duke@435	12	* version 2 for more details (a copy is included in the LICENSE file that
duke@435	13	* accompanied this code).
duke@435	14	*
duke@435	15	* You should have received a copy of the GNU General Public License version
duke@435	16	* 2 along with this work; if not, write to the Free Software Foundation,
duke@435	17	* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
duke@435	18	*
trims@1907	19	* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
trims@1907	20	* or visit www.oracle.com if you need additional information or have any
trims@1907	21	* questions.
duke@435	22	*
duke@435	23	*/
duke@435	24
stefank@2314	25	#include "precompiled.hpp"
stefank@2314	26	#include "memory/genCollectedHeap.hpp"
stefank@2314	27	#include "memory/resourceArea.hpp"
stefank@2314	28	#include "memory/threadLocalAllocBuffer.inline.hpp"
stefank@2314	29	#include "memory/universe.inline.hpp"
stefank@2314	30	#include "oops/oop.inline.hpp"
stefank@4299	31	#include "runtime/thread.inline.hpp"
stefank@2314	32	#include "utilities/copy.hpp"
stefank@2314	33
duke@435	34	// Thread-Local Edens support
duke@435	35
duke@435	36	// static member initialization
duke@435	37	unsigned ThreadLocalAllocBuffer::_target_refills = 0;
duke@435	38	GlobalTLABStats* ThreadLocalAllocBuffer::_global_stats = NULL;
duke@435	39
duke@435	40	void ThreadLocalAllocBuffer::clear_before_allocation() {
duke@435	41	_slow_refill_waste += (unsigned)remaining();
duke@435	42	make_parsable(true); // also retire the TLAB
duke@435	43	}
duke@435	44
duke@435	45	void ThreadLocalAllocBuffer::accumulate_statistics_before_gc() {
duke@435	46	global_stats()->initialize();
duke@435	47
duke@435	48	for(JavaThread *thread = Threads::first(); thread; thread = thread->next()) {
duke@435	49	thread->tlab().accumulate_statistics();
duke@435	50	thread->tlab().initialize_statistics();
duke@435	51	}
duke@435	52
duke@435	53	// Publish new stats if some allocation occurred.
duke@435	54	if (global_stats()->allocation() != 0) {
duke@435	55	global_stats()->publish();
duke@435	56	if (PrintTLAB) {
duke@435	57	global_stats()->print();
duke@435	58	}
duke@435	59	}
duke@435	60	}
duke@435	61
duke@435	62	void ThreadLocalAllocBuffer::accumulate_statistics() {
duke@435	63	size_t capacity = Universe::heap()->tlab_capacity(myThread()) / HeapWordSize;
duke@435	64	size_t unused = Universe::heap()->unsafe_max_tlab_alloc(myThread()) / HeapWordSize;
duke@435	65	size_t used = capacity - unused;
duke@435	66
duke@435	67	// Update allocation history if a reasonable amount of eden was allocated.
duke@435	68	bool update_allocation_history = used > 0.5 * capacity;
duke@435	69
duke@435	70	_gc_waste += (unsigned)remaining();
duke@435	71
duke@435	72	if (PrintTLAB && (_number_of_refills > 0 || Verbose)) {
duke@435	73	print_stats("gc");
duke@435	74	}
duke@435	75
duke@435	76	if (_number_of_refills > 0) {
duke@435	77
duke@435	78	if (update_allocation_history) {
duke@435	79	// Average the fraction of eden allocated in a tlab by this
duke@435	80	// thread for use in the next resize operation.
duke@435	81	// _gc_waste is not subtracted because it's included in
duke@435	82	// "used".
duke@435	83	size_t allocation = _number_of_refills * desired_size();
duke@435	84	double alloc_frac = allocation / (double) used;
duke@435	85	_allocation_fraction.sample(alloc_frac);
duke@435	86	}
duke@435	87	global_stats()->update_allocating_threads();
duke@435	88	global_stats()->update_number_of_refills(_number_of_refills);
duke@435	89	global_stats()->update_allocation(_number_of_refills * desired_size());
duke@435	90	global_stats()->update_gc_waste(_gc_waste);
duke@435	91	global_stats()->update_slow_refill_waste(_slow_refill_waste);
duke@435	92	global_stats()->update_fast_refill_waste(_fast_refill_waste);
duke@435	93
duke@435	94	} else {
duke@435	95	assert(_number_of_refills == 0 && _fast_refill_waste == 0 &&
duke@435	96	_slow_refill_waste == 0 && _gc_waste == 0,
duke@435	97	"tlab stats == 0");
duke@435	98	}
duke@435	99	global_stats()->update_slow_allocations(_slow_allocations);
duke@435	100	}
duke@435	101
duke@435	102	// Fills the current tlab with a dummy filler array to create
duke@435	103	// an illusion of a contiguous Eden and optionally retires the tlab.
duke@435	104	// Waste accounting should be done in caller as appropriate; see,
duke@435	105	// for example, clear_before_allocation().
duke@435	106	void ThreadLocalAllocBuffer::make_parsable(bool retire) {
duke@435	107	if (end() != NULL) {
duke@435	108	invariants();
phh@2423	109
phh@2423	110	if (retire) {
phh@2423	111	myThread()->incr_allocated_bytes(used_bytes());
phh@2423	112	}
phh@2423	113
johnc@1600	114	CollectedHeap::fill_with_object(top(), hard_end(), retire);
duke@435	115
duke@435	116	if (retire || ZeroTLAB) { // "Reset" the TLAB
duke@435	117	set_start(NULL);
duke@435	118	set_top(NULL);
duke@435	119	set_pf_top(NULL);
duke@435	120	set_end(NULL);
duke@435	121	}
duke@435	122	}
duke@435	123	assert(!(retire || ZeroTLAB) ||
duke@435	124	(start() == NULL && end() == NULL && top() == NULL),
duke@435	125	"TLAB must be reset");
duke@435	126	}
duke@435	127
duke@435	128	void ThreadLocalAllocBuffer::resize_all_tlabs() {
duke@435	129	for(JavaThread *thread = Threads::first(); thread; thread = thread->next()) {
duke@435	130	thread->tlab().resize();
duke@435	131	}
duke@435	132	}
duke@435	133
duke@435	134	void ThreadLocalAllocBuffer::resize() {
duke@435	135
duke@435	136	if (ResizeTLAB) {
duke@435	137	// Compute the next tlab size using expected allocation amount
duke@435	138	size_t alloc = (size_t)(_allocation_fraction.average() *
duke@435	139	(Universe::heap()->tlab_capacity(myThread()) / HeapWordSize));
duke@435	140	size_t new_size = alloc / _target_refills;
duke@435	141
duke@435	142	new_size = MIN2(MAX2(new_size, min_size()), max_size());
duke@435	143
duke@435	144	size_t aligned_new_size = align_object_size(new_size);
duke@435	145
duke@435	146	if (PrintTLAB && Verbose) {
duke@435	147	gclog_or_tty->print("TLAB new size: thread: " INTPTR_FORMAT " [id: %2d]"
duke@435	148	" refills %d alloc: %8.6f desired_size: " SIZE_FORMAT " -> " SIZE_FORMAT "\n",
duke@435	149	myThread(), myThread()->osthread()->thread_id(),
duke@435	150	_target_refills, _allocation_fraction.average(), desired_size(), aligned_new_size);
duke@435	151	}
duke@435	152	set_desired_size(aligned_new_size);
duke@435	153
duke@435	154	set_refill_waste_limit(initial_refill_waste_limit());
duke@435	155	}
duke@435	156	}
duke@435	157
duke@435	158	void ThreadLocalAllocBuffer::initialize_statistics() {
duke@435	159	_number_of_refills = 0;
duke@435	160	_fast_refill_waste = 0;
duke@435	161	_slow_refill_waste = 0;
duke@435	162	_gc_waste = 0;
duke@435	163	_slow_allocations = 0;
duke@435	164	}
duke@435	165
duke@435	166	void ThreadLocalAllocBuffer::fill(HeapWord* start,
duke@435	167	HeapWord* top,
duke@435	168	size_t new_size) {
duke@435	169	_number_of_refills++;
duke@435	170	if (PrintTLAB && Verbose) {
duke@435	171	print_stats("fill");
duke@435	172	}
duke@435	173	assert(top <= start + new_size - alignment_reserve(), "size too small");
duke@435	174	initialize(start, top, start + new_size - alignment_reserve());
duke@435	175
duke@435	176	// Reset amount of internal fragmentation
duke@435	177	set_refill_waste_limit(initial_refill_waste_limit());
duke@435	178	}
duke@435	179
duke@435	180	void ThreadLocalAllocBuffer::initialize(HeapWord* start,
duke@435	181	HeapWord* top,
duke@435	182	HeapWord* end) {
duke@435	183	set_start(start);
duke@435	184	set_top(top);
duke@435	185	set_pf_top(top);
duke@435	186	set_end(end);
duke@435	187	invariants();
duke@435	188	}
duke@435	189
duke@435	190	void ThreadLocalAllocBuffer::initialize() {
duke@435	191	initialize(NULL, // start
duke@435	192	NULL, // top
duke@435	193	NULL); // end
duke@435	194
duke@435	195	set_desired_size(initial_desired_size());
duke@435	196
duke@435	197	// Following check is needed because at startup the main (primordial)
duke@435	198	// thread is initialized before the heap is. The initialization for
duke@435	199	// this thread is redone in startup_initialization below.
duke@435	200	if (Universe::heap() != NULL) {
duke@435	201	size_t capacity = Universe::heap()->tlab_capacity(myThread()) / HeapWordSize;
duke@435	202	double alloc_frac = desired_size() * target_refills() / (double) capacity;
duke@435	203	_allocation_fraction.sample(alloc_frac);
duke@435	204	}
duke@435	205
duke@435	206	set_refill_waste_limit(initial_refill_waste_limit());
duke@435	207
duke@435	208	initialize_statistics();
duke@435	209	}
duke@435	210
duke@435	211	void ThreadLocalAllocBuffer::startup_initialization() {
duke@435	212
duke@435	213	// Assuming each thread's active tlab is, on average,
duke@435	214	// 1/2 full at a GC
duke@435	215	_target_refills = 100 / (2 * TLABWasteTargetPercent);
duke@435	216	_target_refills = MAX2(_target_refills, (unsigned)1U);
duke@435	217
duke@435	218	_global_stats = new GlobalTLABStats();
duke@435	219
duke@435	220	// During jvm startup, the main (primordial) thread is initialized
duke@435	221	// before the heap is initialized. So reinitialize it now.
duke@435	222	guarantee(Thread::current()->is_Java_thread(), "tlab initialization thread not Java thread");
duke@435	223	Thread::current()->tlab().initialize();
duke@435	224
duke@435	225	if (PrintTLAB && Verbose) {
duke@435	226	gclog_or_tty->print("TLAB min: " SIZE_FORMAT " initial: " SIZE_FORMAT " max: " SIZE_FORMAT "\n",
duke@435	227	min_size(), Thread::current()->tlab().initial_desired_size(), max_size());
duke@435	228	}
duke@435	229	}
duke@435	230
duke@435	231	size_t ThreadLocalAllocBuffer::initial_desired_size() {
duke@435	232	size_t init_sz;
duke@435	233
duke@435	234	if (TLABSize > 0) {
duke@435	235	init_sz = MIN2(TLABSize / HeapWordSize, max_size());
duke@435	236	} else if (global_stats() == NULL) {
duke@435	237	// Startup issue - main thread initialized before heap initialized.
duke@435	238	init_sz = min_size();
duke@435	239	} else {
duke@435	240	// Initial size is a function of the average number of allocating threads.
duke@435	241	unsigned nof_threads = global_stats()->allocating_threads_avg();
duke@435	242
duke@435	243	init_sz = (Universe::heap()->tlab_capacity(myThread()) / HeapWordSize) /
duke@435	244	(nof_threads * target_refills());
duke@435	245	init_sz = align_object_size(init_sz);
duke@435	246	init_sz = MIN2(MAX2(init_sz, min_size()), max_size());
duke@435	247	}
duke@435	248	return init_sz;
duke@435	249	}
duke@435	250
duke@435	251	const size_t ThreadLocalAllocBuffer::max_size() {
duke@435	252
duke@435	253	// TLABs can't be bigger than we can fill with a int[Integer.MAX_VALUE].
duke@435	254	// This restriction could be removed by enabling filling with multiple arrays.
duke@435	255	// If we compute that the reasonable way as
duke@435	256	// header_size + ((sizeof(jint) * max_jint) / HeapWordSize)
duke@435	257	// we'll overflow on the multiply, so we do the divide first.
duke@435	258	// We actually lose a little by dividing first,
duke@435	259	// but that just makes the TLAB somewhat smaller than the biggest array,
duke@435	260	// which is fine, since we'll be able to fill that.
duke@435	261
duke@435	262	size_t unaligned_max_size = typeArrayOopDesc::header_size(T_INT) +
duke@435	263	sizeof(jint) *
duke@435	264	((juint) max_jint / (size_t) HeapWordSize);
duke@435	265	return align_size_down(unaligned_max_size, MinObjAlignment);
duke@435	266	}
duke@435	267
duke@435	268	void ThreadLocalAllocBuffer::print_stats(const char* tag) {
duke@435	269	Thread* thrd = myThread();
duke@435	270	size_t waste = _gc_waste + _slow_refill_waste + _fast_refill_waste;
duke@435	271	size_t alloc = _number_of_refills * _desired_size;
duke@435	272	double waste_percent = alloc == 0 ? 0.0 :
duke@435	273	100.0 * waste / alloc;
duke@435	274	size_t tlab_used = Universe::heap()->tlab_capacity(thrd) -
duke@435	275	Universe::heap()->unsafe_max_tlab_alloc(thrd);
duke@435	276	gclog_or_tty->print("TLAB: %s thread: " INTPTR_FORMAT " [id: %2d]"
duke@435	277	" desired_size: " SIZE_FORMAT "KB"
duke@435	278	" slow allocs: %d refill waste: " SIZE_FORMAT "B"
duke@435	279	" alloc:%8.5f %8.0fKB refills: %d waste %4.1f%% gc: %dB"
duke@435	280	" slow: %dB fast: %dB\n",
duke@435	281	tag, thrd, thrd->osthread()->thread_id(),
duke@435	282	_desired_size / (K / HeapWordSize),
duke@435	283	_slow_allocations, _refill_waste_limit * HeapWordSize,
duke@435	284	_allocation_fraction.average(),
duke@435	285	_allocation_fraction.average() * tlab_used / K,
duke@435	286	_number_of_refills, waste_percent,
duke@435	287	_gc_waste * HeapWordSize,
duke@435	288	_slow_refill_waste * HeapWordSize,
duke@435	289	_fast_refill_waste * HeapWordSize);
duke@435	290	}
duke@435	291
duke@435	292	void ThreadLocalAllocBuffer::verify() {
duke@435	293	HeapWord* p = start();
duke@435	294	HeapWord* t = top();
duke@435	295	HeapWord* prev_p = NULL;
duke@435	296	while (p < t) {
duke@435	297	oop(p)->verify();
duke@435	298	prev_p = p;
duke@435	299	p += oop(p)->size();
duke@435	300	}
duke@435	301	guarantee(p == top(), "end of last object must match end of space");
duke@435	302	}
duke@435	303
duke@435	304	Thread* ThreadLocalAllocBuffer::myThread() {
duke@435	305	return (Thread*)(((char *)this) +
duke@435	306	in_bytes(start_offset()) -
duke@435	307	in_bytes(Thread::tlab_start_offset()));
duke@435	308	}
duke@435	309
duke@435	310
duke@435	311	GlobalTLABStats::GlobalTLABStats() :
duke@435	312	_allocating_threads_avg(TLABAllocationWeight) {
duke@435	313
duke@435	314	initialize();
duke@435	315
duke@435	316	_allocating_threads_avg.sample(1); // One allocating thread at startup
duke@435	317
duke@435	318	if (UsePerfData) {
duke@435	319
duke@435	320	EXCEPTION_MARK;
duke@435	321	ResourceMark rm;
duke@435	322
duke@435	323	char* cname = PerfDataManager::counter_name("tlab", "allocThreads");
duke@435	324	_perf_allocating_threads =
duke@435	325	PerfDataManager::create_variable(SUN_GC, cname, PerfData::U_None, CHECK);
duke@435	326
duke@435	327	cname = PerfDataManager::counter_name("tlab", "fills");
duke@435	328	_perf_total_refills =
duke@435	329	PerfDataManager::create_variable(SUN_GC, cname, PerfData::U_None, CHECK);
duke@435	330
duke@435	331	cname = PerfDataManager::counter_name("tlab", "maxFills");
duke@435	332	_perf_max_refills =
duke@435	333	PerfDataManager::create_variable(SUN_GC, cname, PerfData::U_None, CHECK);
duke@435	334
duke@435	335	cname = PerfDataManager::counter_name("tlab", "alloc");
duke@435	336	_perf_allocation =
duke@435	337	PerfDataManager::create_variable(SUN_GC, cname, PerfData::U_Bytes, CHECK);
duke@435	338
duke@435	339	cname = PerfDataManager::counter_name("tlab", "gcWaste");
duke@435	340	_perf_gc_waste =
duke@435	341	PerfDataManager::create_variable(SUN_GC, cname, PerfData::U_Bytes, CHECK);
duke@435	342
duke@435	343	cname = PerfDataManager::counter_name("tlab", "maxGcWaste");
duke@435	344	_perf_max_gc_waste =
duke@435	345	PerfDataManager::create_variable(SUN_GC, cname, PerfData::U_Bytes, CHECK);
duke@435	346
duke@435	347	cname = PerfDataManager::counter_name("tlab", "slowWaste");
duke@435	348	_perf_slow_refill_waste =
duke@435	349	PerfDataManager::create_variable(SUN_GC, cname, PerfData::U_Bytes, CHECK);
duke@435	350
duke@435	351	cname = PerfDataManager::counter_name("tlab", "maxSlowWaste");
duke@435	352	_perf_max_slow_refill_waste =
duke@435	353	PerfDataManager::create_variable(SUN_GC, cname, PerfData::U_Bytes, CHECK);
duke@435	354
duke@435	355	cname = PerfDataManager::counter_name("tlab", "fastWaste");
duke@435	356	_perf_fast_refill_waste =
duke@435	357	PerfDataManager::create_variable(SUN_GC, cname, PerfData::U_Bytes, CHECK);
duke@435	358
duke@435	359	cname = PerfDataManager::counter_name("tlab", "maxFastWaste");
duke@435	360	_perf_max_fast_refill_waste =
duke@435	361	PerfDataManager::create_variable(SUN_GC, cname, PerfData::U_Bytes, CHECK);
duke@435	362
duke@435	363	cname = PerfDataManager::counter_name("tlab", "slowAlloc");
duke@435	364	_perf_slow_allocations =
duke@435	365	PerfDataManager::create_variable(SUN_GC, cname, PerfData::U_None, CHECK);
duke@435	366
duke@435	367	cname = PerfDataManager::counter_name("tlab", "maxSlowAlloc");
duke@435	368	_perf_max_slow_allocations =
duke@435	369	PerfDataManager::create_variable(SUN_GC, cname, PerfData::U_None, CHECK);
duke@435	370	}
duke@435	371	}
duke@435	372
duke@435	373	void GlobalTLABStats::initialize() {
duke@435	374	// Clear counters summarizing info from all threads
duke@435	375	_allocating_threads = 0;
duke@435	376	_total_refills = 0;
duke@435	377	_max_refills = 0;
duke@435	378	_total_allocation = 0;
duke@435	379	_total_gc_waste = 0;
duke@435	380	_max_gc_waste = 0;
duke@435	381	_total_slow_refill_waste = 0;
duke@435	382	_max_slow_refill_waste = 0;
duke@435	383	_total_fast_refill_waste = 0;
duke@435	384	_max_fast_refill_waste = 0;
duke@435	385	_total_slow_allocations = 0;
duke@435	386	_max_slow_allocations = 0;
duke@435	387	}
duke@435	388
duke@435	389	void GlobalTLABStats::publish() {
duke@435	390	_allocating_threads_avg.sample(_allocating_threads);
duke@435	391	if (UsePerfData) {
duke@435	392	_perf_allocating_threads ->set_value(_allocating_threads);
duke@435	393	_perf_total_refills ->set_value(_total_refills);
duke@435	394	_perf_max_refills ->set_value(_max_refills);
duke@435	395	_perf_allocation ->set_value(_total_allocation);
duke@435	396	_perf_gc_waste ->set_value(_total_gc_waste);
duke@435	397	_perf_max_gc_waste ->set_value(_max_gc_waste);
duke@435	398	_perf_slow_refill_waste ->set_value(_total_slow_refill_waste);
duke@435	399	_perf_max_slow_refill_waste->set_value(_max_slow_refill_waste);
duke@435	400	_perf_fast_refill_waste ->set_value(_total_fast_refill_waste);
duke@435	401	_perf_max_fast_refill_waste->set_value(_max_fast_refill_waste);
duke@435	402	_perf_slow_allocations ->set_value(_total_slow_allocations);
duke@435	403	_perf_max_slow_allocations ->set_value(_max_slow_allocations);
duke@435	404	}
duke@435	405	}
duke@435	406
duke@435	407	void GlobalTLABStats::print() {
duke@435	408	size_t waste = _total_gc_waste + _total_slow_refill_waste + _total_fast_refill_waste;
duke@435	409	double waste_percent = _total_allocation == 0 ? 0.0 :
duke@435	410	100.0 * waste / _total_allocation;
duke@435	411	gclog_or_tty->print("TLAB totals: thrds: %d refills: %d max: %d"
duke@435	412	" slow allocs: %d max %d waste: %4.1f%%"
duke@435	413	" gc: " SIZE_FORMAT "B max: " SIZE_FORMAT "B"
duke@435	414	" slow: " SIZE_FORMAT "B max: " SIZE_FORMAT "B"
duke@435	415	" fast: " SIZE_FORMAT "B max: " SIZE_FORMAT "B\n",
duke@435	416	_allocating_threads,
duke@435	417	_total_refills, _max_refills,
duke@435	418	_total_slow_allocations, _max_slow_allocations,
duke@435	419	waste_percent,
duke@435	420	_total_gc_waste * HeapWordSize,
duke@435	421	_max_gc_waste * HeapWordSize,
duke@435	422	_total_slow_refill_waste * HeapWordSize,
duke@435	423	_max_slow_refill_waste * HeapWordSize,
duke@435	424	_total_fast_refill_waste * HeapWordSize,
duke@435	425	_max_fast_refill_waste * HeapWordSize);
duke@435	426	}