1 /*
2 * Copyright (c) 2017, 2018, Red Hat, Inc. All rights reserved.
3 *
4 * This code is free software; you can redistribute it and/or modify it
5 * under the terms of the GNU General Public License version 2 only, as
6 * published by the Free Software Foundation.
7 *
8 * This code is distributed in the hope that it will be useful, but WITHOUT
9 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
10 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
11 * version 2 for more details (a copy is included in the LICENSE file that
12 * accompanied this code).
13 *
14 * You should have received a copy of the GNU General Public License version
15 * 2 along with this work; if not, write to the Free Software Foundation,
16 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
17 *
18 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
19 * or visit www.oracle.com if you need additional information or have any
20 * questions.
21 *
22 */
23
24 #include "precompiled.hpp"
25 #include "gc/epsilon/epsilonHeap.hpp"
26 #include "gc/epsilon/epsilonMemoryPool.hpp"
27 #include "memory/allocation.hpp"
28 #include "memory/allocation.inline.hpp"
29 #include "memory/resourceArea.hpp"
30
31 jint EpsilonHeap::initialize() {
32 size_t init_byte_size = _policy->initial_heap_byte_size();
33 size_t max_byte_size = _policy->max_heap_byte_size();
34 size_t align = _policy->heap_alignment();
35
36 ReservedSpace heap_rs = Universe::reserve_heap(max_byte_size, align);
37 _virtual_space.initialize(heap_rs, init_byte_size);
38
39 MemRegion committed_region((HeapWord*)_virtual_space.low(), (HeapWord*)_virtual_space.high());
40 MemRegion reserved_region((HeapWord*)_virtual_space.low_boundary(), (HeapWord*)_virtual_space.high_boundary());
41
42 initialize_reserved_region(reserved_region.start(), reserved_region.end());
43
44 _space = new ContiguousSpace();
45 _space->initialize(committed_region, true, true);
46
47 BarrierSet::set_barrier_set(new EpsilonBarrierSet());
48
49 _max_tlab_size = MIN2(CollectedHeap::max_tlab_size(), EpsilonMaxTLABSize / HeapWordSize);
50
51 _monitoring_support = new EpsilonMonitoringSupport(this);
52 _last_counter_update = 0;
53 _last_heap_print = 0;
54
55 _step_counter_update = MIN2<size_t>(max_byte_size / 16, EpsilonUpdateCountersStep);
56 _step_heap_print = (EpsilonPrintHeapStep == 0) ? SIZE_MAX : (max_byte_size / EpsilonPrintHeapStep);
57
58 if (init_byte_size != max_byte_size) {
59 log_info(gc)("Initialized with " SIZE_FORMAT "M heap, resizeable to up to " SIZE_FORMAT "M heap with " SIZE_FORMAT "M steps",
60 init_byte_size / M, max_byte_size / M, EpsilonMinHeapExpand / M);
61 } else {
62 log_info(gc)("Initialized with " SIZE_FORMAT "M non-resizeable heap", init_byte_size / M);
63 }
64 if (UseTLAB) {
65 log_info(gc)("Using TLAB allocation; min: " SIZE_FORMAT "K, max: " SIZE_FORMAT "K",
66 ThreadLocalAllocBuffer::min_size() * HeapWordSize / K,
67 _max_tlab_size*HeapWordSize / K);
68 } else {
69 log_info(gc)("Not using TLAB allocation");
70 }
71
72 return JNI_OK;
73 }
74
75 void EpsilonHeap::post_initialize() {
76 CollectedHeap::post_initialize();
77 }
78
79 void EpsilonHeap::initialize_serviceability() {
80 _pool = new EpsilonMemoryPool(this);
81 _memory_manager.add_pool(_pool);
82 }
83
84 GrowableArray<GCMemoryManager*> EpsilonHeap::memory_managers() {
85 GrowableArray<GCMemoryManager*> memory_managers(1);
86 memory_managers.append(&_memory_manager);
87 return memory_managers;
88 }
89
90 GrowableArray<MemoryPool*> EpsilonHeap::memory_pools() {
91 GrowableArray<MemoryPool*> memory_pools(1);
92 memory_pools.append(_pool);
93 return memory_pools;
94 }
95
96 size_t EpsilonHeap::unsafe_max_tlab_alloc(Thread* thr) const {
97 // This is the only way we can control TLAB sizes without having safepoints.
98 // Implement exponential expansion within [MinTLABSize; _max_tlab_size], based
99 // on previously "used" TLAB size.
100
101 size_t size = MIN2(_max_tlab_size * HeapWordSize, MAX2(MinTLABSize, thr->tlab().used() * HeapWordSize * 2));
102
103 if (log_is_enabled(Trace, gc)) {
104 ResourceMark rm;
105 log_trace(gc)(
106 "Selecting TLAB size for \"%s\" (Desired: " SIZE_FORMAT "K, Used: " SIZE_FORMAT "K) -> " SIZE_FORMAT "K",
107 Thread::current()->name(),
108 thr->tlab().desired_size() * HeapWordSize / K,
109 thr->tlab().used() * HeapWordSize / K,
110 size / K);
111 }
112
113 return size;
114 }
115
116 EpsilonHeap* EpsilonHeap::heap() {
117 CollectedHeap* heap = Universe::heap();
118 assert(heap != NULL, "Uninitialized access to EpsilonHeap::heap()");
119 assert(heap->kind() == CollectedHeap::Epsilon, "Not an Epsilon heap");
120 return (EpsilonHeap*)heap;
121 }
122
123 HeapWord* EpsilonHeap::allocate_work(size_t size) {
124 HeapWord* res = _space->par_allocate(size);
125
126 while (res == NULL) {
127 // Allocation failed, attempt expansion, and retry:
128 MutexLockerEx ml(Heap_lock);
129
130 size_t space_left = max_capacity() - capacity();
131 size_t want_space = MAX2(size, EpsilonMinHeapExpand);
132
133 if (want_space < space_left) {
134 // Enough space to expand in bulk:
135 bool expand = _virtual_space.expand_by(want_space);
136 assert(expand, "Should be able to expand");
137 } else if (size < space_left) {
138 // No space to expand in bulk, and this allocation is still possible,
139 // take all the space left:
140 bool expand = _virtual_space.expand_by(space_left);
141 assert(expand, "Should be able to expand");
142 } else {
143 // No space left:
144 return NULL;
145 }
146
147 _space->set_end((HeapWord *) _virtual_space.high());
148 res = _space->par_allocate(size);
149 }
150
151 size_t used = _space->used();
152 if (used - _last_counter_update >= _step_counter_update) {
153 _last_counter_update = used;
154 _monitoring_support->update_counters();
155 }
156
157 if (used - _last_heap_print >= _step_heap_print) {
158 log_info(gc)("Heap: " SIZE_FORMAT "M reserved, " SIZE_FORMAT "M committed, " SIZE_FORMAT "M used",
159 max_capacity() / M, capacity() / M, used / M);
160 _last_heap_print = used;
161 }
162
163 return res;
164 }
165
166 HeapWord* EpsilonHeap::allocate_new_tlab(size_t size) {
167 return allocate_work(size);
168 }
169
170 HeapWord* EpsilonHeap::mem_allocate(size_t size, bool *gc_overhead_limit_was_exceeded) {
171 *gc_overhead_limit_was_exceeded = false;
172 return allocate_work(size);
173 }
174
175 void EpsilonHeap::collect(GCCause::Cause cause) {
176 log_info(gc)("GC request for \"%s\" is ignored", GCCause::to_string(cause));
177 _monitoring_support->update_counters();
178 }
179
180 void EpsilonHeap::do_full_collection(bool clear_all_soft_refs) {
181 log_info(gc)("Full GC request for \"%s\" is ignored", GCCause::to_string(gc_cause()));
182 _monitoring_support->update_counters();
183 }
184
185 void EpsilonHeap::safe_object_iterate(ObjectClosure *cl) {
186 _space->safe_object_iterate(cl);
187 }
188
189 void EpsilonHeap::print_on(outputStream *st) const {
190 st->print_cr("Epsilon Heap");
191
192 // Cast away constness:
193 ((VirtualSpace)_virtual_space).print_on(st);
194
195 st->print_cr("Allocation space:");
196 _space->print_on(st);
197 }
198
199 void EpsilonHeap::print_tracing_info() const {
200 Log(gc) log;
201 size_t allocated_kb = used() / K;
202 log.info("Total allocated: " SIZE_FORMAT " KB",
203 allocated_kb);
204 log.info("Average allocation rate: " SIZE_FORMAT " KB/sec",
205 (size_t)(allocated_kb * NANOSECS_PER_SEC / os::elapsed_counter()));
206 }