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src/share/vm/gc_implementation/parallelScavenge/adjoiningGenerations.cpp@ad72068ac41e (annotated)

src/share/vm/gc_implementation/parallelScavenge/adjoiningGenerations.cpp

Tue, 10 Dec 2013 10:31:00 +0100

author

sjohanss

date

Tue, 10 Dec 2013 10:31:00 +0100

changeset 6169

ad72068ac41e

parent 6085

8f07aa079343

child 6198

55fb97c4c58d

permissions

-rw-r--r--

8028993: Full collections with ParallelScavenge slower in JDK 8 compared to 7u40
Summary: Reducing the number of calls to follow_class_loader to speed up the marking phase. Also removed some unnecessary calls to adjust_klass.
Reviewed-by: stefank, jmasa, mgerdin

duke@435	1	/*
coleenp@4037	2	* Copyright (c) 2003, 2012, 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 "gc_implementation/parallelScavenge/adjoiningGenerations.hpp"
stefank@2314	27	#include "gc_implementation/parallelScavenge/adjoiningVirtualSpaces.hpp"
jwilhelm@6085	28	#include "gc_implementation/parallelScavenge/generationSizer.hpp"
stefank@2314	29	#include "gc_implementation/parallelScavenge/parallelScavengeHeap.hpp"
duke@435	30
duke@435	31	// If boundary moving is being used, create the young gen and old
duke@435	32	// gen with ASPSYoungGen and ASPSOldGen, respectively. Revert to
duke@435	33	// the old behavior otherwise (with PSYoungGen and PSOldGen).
duke@435	34
duke@435	35	AdjoiningGenerations::AdjoiningGenerations(ReservedSpace old_young_rs,
jwilhelm@6085	36	GenerationSizer* policy,
duke@435	37	size_t alignment) :
jwilhelm@6085	38	_virtual_spaces(old_young_rs, policy->min_gen1_size(),
jwilhelm@6085	39	policy->min_gen0_size(), alignment) {
jwilhelm@6085	40	size_t init_low_byte_size = policy->initial_gen1_size();
jwilhelm@6085	41	size_t min_low_byte_size = policy->min_gen1_size();
jwilhelm@6085	42	size_t max_low_byte_size = policy->max_gen1_size();
jwilhelm@6085	43	size_t init_high_byte_size = policy->initial_gen0_size();
jwilhelm@6085	44	size_t min_high_byte_size = policy->min_gen0_size();
jwilhelm@6085	45	size_t max_high_byte_size = policy->max_gen0_size();
jwilhelm@6085	46
duke@435	47	assert(min_low_byte_size <= init_low_byte_size &&
duke@435	48	init_low_byte_size <= max_low_byte_size, "Parameter check");
duke@435	49	assert(min_high_byte_size <= init_high_byte_size &&
duke@435	50	init_high_byte_size <= max_high_byte_size, "Parameter check");
duke@435	51	// Create the generations differently based on the option to
duke@435	52	// move the boundary.
duke@435	53	if (UseAdaptiveGCBoundary) {
duke@435	54	// Initialize the adjoining virtual spaces. Then pass the
duke@435	55	// a virtual to each generation for initialization of the
duke@435	56	// generation.
duke@435	57
duke@435	58	// Does the actual creation of the virtual spaces
duke@435	59	_virtual_spaces.initialize(max_low_byte_size,
duke@435	60	init_low_byte_size,
duke@435	61	init_high_byte_size);
duke@435	62
duke@435	63	// Place the young gen at the high end. Passes in the virtual space.
duke@435	64	_young_gen = new ASPSYoungGen(_virtual_spaces.high(),
duke@435	65	_virtual_spaces.high()->committed_size(),
duke@435	66	min_high_byte_size,
duke@435	67	_virtual_spaces.high_byte_size_limit());
duke@435	68
duke@435	69	// Place the old gen at the low end. Passes in the virtual space.
duke@435	70	_old_gen = new ASPSOldGen(_virtual_spaces.low(),
duke@435	71	_virtual_spaces.low()->committed_size(),
duke@435	72	min_low_byte_size,
duke@435	73	_virtual_spaces.low_byte_size_limit(),
duke@435	74	"old", 1);
duke@435	75
duke@435	76	young_gen()->initialize_work();
duke@435	77	assert(young_gen()->reserved().byte_size() <= young_gen()->gen_size_limit(),
duke@435	78	"Consistency check");
duke@435	79	assert(old_young_rs.size() >= young_gen()->gen_size_limit(),
duke@435	80	"Consistency check");
duke@435	81
duke@435	82	old_gen()->initialize_work("old", 1);
duke@435	83	assert(old_gen()->reserved().byte_size() <= old_gen()->gen_size_limit(),
duke@435	84	"Consistency check");
duke@435	85	assert(old_young_rs.size() >= old_gen()->gen_size_limit(),
duke@435	86	"Consistency check");
duke@435	87	} else {
duke@435	88
duke@435	89	// Layout the reserved space for the generations.
duke@435	90	ReservedSpace old_rs =
duke@435	91	virtual_spaces()->reserved_space().first_part(max_low_byte_size);
duke@435	92	ReservedSpace heap_rs =
duke@435	93	virtual_spaces()->reserved_space().last_part(max_low_byte_size);
duke@435	94	ReservedSpace young_rs = heap_rs.first_part(max_high_byte_size);
duke@435	95	assert(young_rs.size() == heap_rs.size(), "Didn't reserve all of the heap");
duke@435	96
duke@435	97	// Create the generations. Virtual spaces are not passed in.
duke@435	98	_young_gen = new PSYoungGen(init_high_byte_size,
duke@435	99	min_high_byte_size,
duke@435	100	max_high_byte_size);
duke@435	101	_old_gen = new PSOldGen(init_low_byte_size,
duke@435	102	min_low_byte_size,
duke@435	103	max_low_byte_size,
duke@435	104	"old", 1);
duke@435	105
duke@435	106	// The virtual spaces are created by the initialization of the gens.
duke@435	107	_young_gen->initialize(young_rs, alignment);
duke@435	108	assert(young_gen()->gen_size_limit() == young_rs.size(),
duke@435	109	"Consistency check");
duke@435	110	_old_gen->initialize(old_rs, alignment, "old", 1);
duke@435	111	assert(old_gen()->gen_size_limit() == old_rs.size(), "Consistency check");
duke@435	112	}
duke@435	113	}
duke@435	114
duke@435	115	size_t AdjoiningGenerations::reserved_byte_size() {
duke@435	116	return virtual_spaces()->reserved_space().size();
duke@435	117	}
duke@435	118
duke@435	119
duke@435	120	// Make checks on the current sizes of the generations and
duke@435	121	// the contraints on the sizes of the generations. Push
duke@435	122	// up the boundary within the contraints. A partial
duke@435	123	// push can occur.
duke@435	124	void AdjoiningGenerations::request_old_gen_expansion(size_t expand_in_bytes) {
duke@435	125	assert(UseAdaptiveSizePolicy && UseAdaptiveGCBoundary, "runtime check");
duke@435	126
duke@435	127	assert_lock_strong(ExpandHeap_lock);
duke@435	128	assert_locked_or_safepoint(Heap_lock);
duke@435	129
duke@435	130	// These sizes limit the amount the boundaries can move. Effectively,
duke@435	131	// the generation says how much it is willing to yield to the other
duke@435	132	// generation.
duke@435	133	const size_t young_gen_available = young_gen()->available_for_contraction();
duke@435	134	const size_t old_gen_available = old_gen()->available_for_expansion();
duke@435	135	const size_t alignment = virtual_spaces()->alignment();
duke@435	136	size_t change_in_bytes = MIN3(young_gen_available,
duke@435	137	old_gen_available,
duke@435	138	align_size_up_(expand_in_bytes, alignment));
duke@435	139
duke@435	140	if (change_in_bytes == 0) {
duke@435	141	return;
duke@435	142	}
duke@435	143
duke@435	144	if (TraceAdaptiveGCBoundary) {
duke@435	145	gclog_or_tty->print_cr("Before expansion of old gen with boundary move");
duke@435	146	gclog_or_tty->print_cr(" Requested change: 0x%x Attempted change: 0x%x",
duke@435	147	expand_in_bytes, change_in_bytes);
duke@435	148	if (!PrintHeapAtGC) {
duke@435	149	Universe::print_on(gclog_or_tty);
duke@435	150	}
duke@435	151	gclog_or_tty->print_cr(" PSOldGen max size: " SIZE_FORMAT "K",
duke@435	152	old_gen()->max_gen_size()/K);
duke@435	153	}
duke@435	154
duke@435	155	// Move the boundary between the generations up (smaller young gen).
duke@435	156	if (virtual_spaces()->adjust_boundary_up(change_in_bytes)) {
duke@435	157	young_gen()->reset_after_change();
duke@435	158	old_gen()->reset_after_change();
duke@435	159	}
duke@435	160
duke@435	161	// The total reserved for the generations should match the sum
duke@435	162	// of the two even if the boundary is moving.
duke@435	163	assert(reserved_byte_size() ==
duke@435	164	old_gen()->max_gen_size() + young_gen()->max_size(),
duke@435	165	"Space is missing");
duke@435	166	young_gen()->space_invariants();
duke@435	167	old_gen()->space_invariants();
duke@435	168
duke@435	169	if (TraceAdaptiveGCBoundary) {
duke@435	170	gclog_or_tty->print_cr("After expansion of old gen with boundary move");
duke@435	171	if (!PrintHeapAtGC) {
duke@435	172	Universe::print_on(gclog_or_tty);
duke@435	173	}
duke@435	174	gclog_or_tty->print_cr(" PSOldGen max size: " SIZE_FORMAT "K",
duke@435	175	old_gen()->max_gen_size()/K);
duke@435	176	}
duke@435	177	}
duke@435	178
duke@435	179	// See comments on request_old_gen_expansion()
duke@435	180	bool AdjoiningGenerations::request_young_gen_expansion(size_t expand_in_bytes) {
duke@435	181	assert(UseAdaptiveSizePolicy && UseAdaptiveGCBoundary, "runtime check");
duke@435	182
duke@435	183	// If eden is not empty, the boundary can be moved but no advantage
duke@435	184	// can be made of the move since eden cannot be moved.
duke@435	185	if (!young_gen()->eden_space()->is_empty()) {
duke@435	186	return false;
duke@435	187	}
duke@435	188
duke@435	189
duke@435	190	bool result = false;
duke@435	191	const size_t young_gen_available = young_gen()->available_for_expansion();
duke@435	192	const size_t old_gen_available = old_gen()->available_for_contraction();
duke@435	193	const size_t alignment = virtual_spaces()->alignment();
duke@435	194	size_t change_in_bytes = MIN3(young_gen_available,
duke@435	195	old_gen_available,
duke@435	196	align_size_up_(expand_in_bytes, alignment));
duke@435	197
duke@435	198	if (change_in_bytes == 0) {
duke@435	199	return false;
duke@435	200	}
duke@435	201
duke@435	202	if (TraceAdaptiveGCBoundary) {
duke@435	203	gclog_or_tty->print_cr("Before expansion of young gen with boundary move");
duke@435	204	gclog_or_tty->print_cr(" Requested change: 0x%x Attempted change: 0x%x",
duke@435	205	expand_in_bytes, change_in_bytes);
duke@435	206	if (!PrintHeapAtGC) {
duke@435	207	Universe::print_on(gclog_or_tty);
duke@435	208	}
duke@435	209	gclog_or_tty->print_cr(" PSYoungGen max size: " SIZE_FORMAT "K",
duke@435	210	young_gen()->max_size()/K);
duke@435	211	}
duke@435	212
duke@435	213	// Move the boundary between the generations down (smaller old gen).
duke@435	214	MutexLocker x(ExpandHeap_lock);
duke@435	215	if (virtual_spaces()->adjust_boundary_down(change_in_bytes)) {
duke@435	216	young_gen()->reset_after_change();
duke@435	217	old_gen()->reset_after_change();
duke@435	218	result = true;
duke@435	219	}
duke@435	220
duke@435	221	// The total reserved for the generations should match the sum
duke@435	222	// of the two even if the boundary is moving.
duke@435	223	assert(reserved_byte_size() ==
duke@435	224	old_gen()->max_gen_size() + young_gen()->max_size(),
duke@435	225	"Space is missing");
duke@435	226	young_gen()->space_invariants();
duke@435	227	old_gen()->space_invariants();
duke@435	228
duke@435	229	if (TraceAdaptiveGCBoundary) {
duke@435	230	gclog_or_tty->print_cr("After expansion of young gen with boundary move");
duke@435	231	if (!PrintHeapAtGC) {
duke@435	232	Universe::print_on(gclog_or_tty);
duke@435	233	}
duke@435	234	gclog_or_tty->print_cr(" PSYoungGen max size: " SIZE_FORMAT "K",
duke@435	235	young_gen()->max_size()/K);
duke@435	236	}
duke@435	237
duke@435	238	return result;
duke@435	239	}
duke@435	240
duke@435	241	// Additional space is needed in the old generation. Try to move the boundary
duke@435	242	// up to meet the need. Moves boundary up only
duke@435	243	void AdjoiningGenerations::adjust_boundary_for_old_gen_needs(
duke@435	244	size_t desired_free_space) {
duke@435	245	assert(UseAdaptiveSizePolicy && UseAdaptiveGCBoundary, "runtime check");
duke@435	246
duke@435	247	// Stress testing.
duke@435	248	if (PSAdaptiveSizePolicyResizeVirtualSpaceAlot == 1) {
duke@435	249	MutexLocker x(ExpandHeap_lock);
duke@435	250	request_old_gen_expansion(virtual_spaces()->alignment() * 3 / 2);
duke@435	251	}
duke@435	252
duke@435	253	// Expand only if the entire generation is already committed.
duke@435	254	if (old_gen()->virtual_space()->uncommitted_size() == 0) {
duke@435	255	if (old_gen()->free_in_bytes() < desired_free_space) {
duke@435	256	MutexLocker x(ExpandHeap_lock);
duke@435	257	request_old_gen_expansion(desired_free_space);
duke@435	258	}
duke@435	259	}
duke@435	260	}
duke@435	261
duke@435	262	// See comment on adjust_boundary_for_old_gen_needss().
duke@435	263	// Adjust boundary down only.
duke@435	264	void AdjoiningGenerations::adjust_boundary_for_young_gen_needs(size_t eden_size,
duke@435	265	size_t survivor_size) {
duke@435	266
duke@435	267	assert(UseAdaptiveSizePolicy && UseAdaptiveGCBoundary, "runtime check");
duke@435	268
duke@435	269	// Stress testing.
duke@435	270	if (PSAdaptiveSizePolicyResizeVirtualSpaceAlot == 0) {
duke@435	271	request_young_gen_expansion(virtual_spaces()->alignment() * 3 / 2);
duke@435	272	eden_size = young_gen()->eden_space()->capacity_in_bytes();
duke@435	273	}
duke@435	274
duke@435	275	// Expand only if the entire generation is already committed.
duke@435	276	if (young_gen()->virtual_space()->uncommitted_size() == 0) {
duke@435	277	size_t desired_size = eden_size + 2 * survivor_size;
duke@435	278	const size_t committed = young_gen()->virtual_space()->committed_size();
duke@435	279	if (desired_size > committed) {
duke@435	280	request_young_gen_expansion(desired_size - committed);
duke@435	281	}
duke@435	282	}
duke@435	283	}