1 /*
2 * Copyright (c) 1999, 2015, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation.
8 *
9 * This code is distributed in the hope that it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
12 * version 2 for more details (a copy is included in the LICENSE file that
13 * accompanied this code).
14 *
15 * You should have received a copy of the GNU General Public License version
16 * 2 along with this work; if not, write to the Free Software Foundation,
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
18 *
19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
20 * or visit www.oracle.com if you need additional information or have any
21 * questions.
22 *
23 */
24
25 #ifndef SHARE_VM_GC_SHARED_THREADLOCALALLOCBUFFER_HPP
26 #define SHARE_VM_GC_SHARED_THREADLOCALALLOCBUFFER_HPP
27
28 #include "gc/shared/gcUtil.hpp"
29 #include "oops/typeArrayOop.hpp"
30 #include "runtime/perfData.hpp"
31 #include "runtime/vm_version.hpp"
32
33 class GlobalTLABStats;
34
35 // ThreadLocalAllocBuffer: a descriptor for thread-local storage used by
36 // the threads for allocation.
37 // It is thread-private at any time, but maybe multiplexed over
38 // time across multiple threads. The park()/unpark() pair is
39 // used to make it available for such multiplexing.
40 class ThreadLocalAllocBuffer: public CHeapObj<mtThread> {
41 friend class VMStructs;
42 private:
43 HeapWord* _start; // address of TLAB
44 HeapWord* _top; // address after last allocation
45 HeapWord* _pf_top; // allocation prefetch watermark
46 HeapWord* _end; // allocation end (excluding alignment_reserve)
47 size_t _desired_size; // desired size (including alignment_reserve)
48 size_t _refill_waste_limit; // hold onto tlab if free() is larger than this
49 size_t _allocated_before_last_gc; // total bytes allocated up until the last gc
50
51 static size_t _max_size; // maximum size of any TLAB
52 static unsigned _target_refills; // expected number of refills between GCs
53
54 unsigned _number_of_refills;
55 unsigned _fast_refill_waste;
56 unsigned _slow_refill_waste;
57 unsigned _gc_waste;
58 unsigned _slow_allocations;
59
60 AdaptiveWeightedAverage _allocation_fraction; // fraction of eden allocated in tlabs
61
62 void accumulate_statistics();
63 void initialize_statistics();
64
65 void set_start(HeapWord* start) { _start = start; }
66 void set_end(HeapWord* end) { _end = end; }
67 void set_top(HeapWord* top) { _top = top; }
68 void set_pf_top(HeapWord* pf_top) { _pf_top = pf_top; }
69 void set_desired_size(size_t desired_size) { _desired_size = desired_size; }
70 void set_refill_waste_limit(size_t waste) { _refill_waste_limit = waste; }
71
72 size_t initial_refill_waste_limit() { return desired_size() / TLABRefillWasteFraction; }
73
74 static int target_refills() { return _target_refills; }
75 size_t initial_desired_size();
76
77 size_t remaining() const { return end() == NULL ? 0 : pointer_delta(hard_end(), top()); }
78
79 // Make parsable and release it.
80 void reset();
81
82 // Resize based on amount of allocation, etc.
83 void resize();
84
85 void invariants() const { assert(top() >= start() && top() <= end(), "invalid tlab"); }
86
87 void initialize(HeapWord* start, HeapWord* top, HeapWord* end);
88
89 void print_stats(const char* tag);
90
91 Thread* myThread();
92
93 // statistics
94
95 int number_of_refills() const { return _number_of_refills; }
96 int fast_refill_waste() const { return _fast_refill_waste; }
97 int slow_refill_waste() const { return _slow_refill_waste; }
98 int gc_waste() const { return _gc_waste; }
99 int slow_allocations() const { return _slow_allocations; }
100
101 static GlobalTLABStats* _global_stats;
102 static GlobalTLABStats* global_stats() { return _global_stats; }
103
104 public:
105 ThreadLocalAllocBuffer() : _allocation_fraction(TLABAllocationWeight), _allocated_before_last_gc(0) {
106 // do nothing. tlabs must be inited by initialize() calls
107 }
108
109 static const size_t min_size() { return align_object_size(MinTLABSize / HeapWordSize) + alignment_reserve(); }
110 static const size_t max_size() { assert(_max_size != 0, "max_size not set up"); return _max_size; }
111 static void set_max_size(size_t max_size) { _max_size = max_size; }
112
113 HeapWord* start() const { return _start; }
114 HeapWord* end() const { return _end; }
115 HeapWord* hard_end() const { return _end + alignment_reserve(); }
116 HeapWord* top() const { return _top; }
117 HeapWord* pf_top() const { return _pf_top; }
118 size_t desired_size() const { return _desired_size; }
119 size_t used() const { return pointer_delta(top(), start()); }
120 size_t used_bytes() const { return pointer_delta(top(), start(), 1); }
121 size_t free() const { return pointer_delta(end(), top()); }
122 // Don't discard tlab if remaining space is larger than this.
123 size_t refill_waste_limit() const { return _refill_waste_limit; }
124
125 // Allocate size HeapWords. The memory is NOT initialized to zero.
126 inline HeapWord* allocate(size_t size);
127
128 // Reserve space at the end of TLAB
129 static size_t end_reserve() {
130 int reserve_size = typeArrayOopDesc::header_size(T_INT);
131 return MAX2(reserve_size, VM_Version::reserve_for_allocation_prefetch());
132 }
133 static size_t alignment_reserve() { return align_object_size(end_reserve()); }
134 static size_t alignment_reserve_in_bytes() { return alignment_reserve() * HeapWordSize; }
135
136 // Return tlab size or remaining space in eden such that the
137 // space is large enough to hold obj_size and necessary fill space.
138 // Otherwise return 0;
139 inline size_t compute_size(size_t obj_size);
140
141 // Record slow allocation
142 inline void record_slow_allocation(size_t obj_size);
143
144 // Initialization at startup
145 static void startup_initialization();
146
147 // Make an in-use tlab parsable, optionally also retiring it.
148 void make_parsable(bool retire);
149
150 // Retire in-use tlab before allocation of a new tlab
151 void clear_before_allocation();
152
153 // Accumulate statistics across all tlabs before gc
154 static void accumulate_statistics_before_gc();
155
156 // Resize tlabs for all threads
157 static void resize_all_tlabs();
158
159 void fill(HeapWord* start, HeapWord* top, size_t new_size);
160 void initialize();
161
162 static size_t refill_waste_limit_increment() { return TLABWasteIncrement; }
163
164 // Code generation support
165 static ByteSize start_offset() { return byte_offset_of(ThreadLocalAllocBuffer, _start); }
166 static ByteSize end_offset() { return byte_offset_of(ThreadLocalAllocBuffer, _end ); }
167 static ByteSize top_offset() { return byte_offset_of(ThreadLocalAllocBuffer, _top ); }
168 static ByteSize pf_top_offset() { return byte_offset_of(ThreadLocalAllocBuffer, _pf_top ); }
169 static ByteSize size_offset() { return byte_offset_of(ThreadLocalAllocBuffer, _desired_size ); }
170 static ByteSize refill_waste_limit_offset() { return byte_offset_of(ThreadLocalAllocBuffer, _refill_waste_limit ); }
171
172 static ByteSize number_of_refills_offset() { return byte_offset_of(ThreadLocalAllocBuffer, _number_of_refills ); }
173 static ByteSize fast_refill_waste_offset() { return byte_offset_of(ThreadLocalAllocBuffer, _fast_refill_waste ); }
174 static ByteSize slow_allocations_offset() { return byte_offset_of(ThreadLocalAllocBuffer, _slow_allocations ); }
175
176 void verify();
177 };
178
179 class GlobalTLABStats: public CHeapObj<mtThread> {
180 private:
181
182 // Accumulate perfdata in private variables because
183 // PerfData should be write-only for security reasons
184 // (see perfData.hpp)
185 unsigned _allocating_threads;
186 unsigned _total_refills;
187 unsigned _max_refills;
188 size_t _total_allocation;
189 size_t _total_gc_waste;
190 size_t _max_gc_waste;
191 size_t _total_slow_refill_waste;
192 size_t _max_slow_refill_waste;
193 size_t _total_fast_refill_waste;
194 size_t _max_fast_refill_waste;
195 unsigned _total_slow_allocations;
196 unsigned _max_slow_allocations;
197
198 PerfVariable* _perf_allocating_threads;
199 PerfVariable* _perf_total_refills;
200 PerfVariable* _perf_max_refills;
201 PerfVariable* _perf_allocation;
202 PerfVariable* _perf_gc_waste;
203 PerfVariable* _perf_max_gc_waste;
204 PerfVariable* _perf_slow_refill_waste;
205 PerfVariable* _perf_max_slow_refill_waste;
206 PerfVariable* _perf_fast_refill_waste;
207 PerfVariable* _perf_max_fast_refill_waste;
208 PerfVariable* _perf_slow_allocations;
209 PerfVariable* _perf_max_slow_allocations;
210
211 AdaptiveWeightedAverage _allocating_threads_avg;
212
213 public:
214 GlobalTLABStats();
215
216 // Initialize all counters
217 void initialize();
218
219 // Write all perf counters to the perf_counters
220 void publish();
221
222 void print();
223
224 // Accessors
225 unsigned allocating_threads_avg() {
226 return MAX2((unsigned)(_allocating_threads_avg.average() + 0.5), 1U);
227 }
228
229 size_t allocation() {
230 return _total_allocation;
231 }
232
233 // Update methods
234
235 void update_allocating_threads() {
236 _allocating_threads++;
237 }
238 void update_number_of_refills(unsigned value) {
239 _total_refills += value;
240 _max_refills = MAX2(_max_refills, value);
241 }
242 void update_allocation(size_t value) {
243 _total_allocation += value;
244 }
245 void update_gc_waste(size_t value) {
246 _total_gc_waste += value;
247 _max_gc_waste = MAX2(_max_gc_waste, value);
248 }
249 void update_fast_refill_waste(size_t value) {
250 _total_fast_refill_waste += value;
251 _max_fast_refill_waste = MAX2(_max_fast_refill_waste, value);
252 }
253 void update_slow_refill_waste(size_t value) {
254 _total_slow_refill_waste += value;
255 _max_slow_refill_waste = MAX2(_max_slow_refill_waste, value);
256 }
257 void update_slow_allocations(unsigned value) {
258 _total_slow_allocations += value;
259 _max_slow_allocations = MAX2(_max_slow_allocations, value);
260 }
261 };
262
263 #endif // SHARE_VM_GC_SHARED_THREADLOCALALLOCBUFFER_HPP