1 /*
2 * Copyright (c) 1999, 2018, 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 friend class JVMCIVMStructs;
43 private:
44 HeapWord* _start; // address of TLAB
45 HeapWord* _top; // address after last allocation
46 HeapWord* _pf_top; // allocation prefetch watermark
47 HeapWord* _end; // allocation end (excluding alignment_reserve)
48 size_t _desired_size; // desired size (including alignment_reserve)
49 size_t _refill_waste_limit; // hold onto tlab if free() is larger than this
50 size_t _allocated_before_last_gc; // total bytes allocated up until the last gc
51
52 static size_t _max_size; // maximum size of any TLAB
53 static int _reserve_for_allocation_prefetch; // Reserve at the end of the TLAB
54 static unsigned _target_refills; // expected number of refills between GCs
55
56 unsigned _number_of_refills;
57 unsigned _fast_refill_waste;
58 unsigned _slow_refill_waste;
59 unsigned _gc_waste;
60 unsigned _slow_allocations;
61 size_t _allocated_size;
62
63 AdaptiveWeightedAverage _allocation_fraction; // fraction of eden allocated in tlabs
64
65 void accumulate_statistics();
66 void initialize_statistics();
67
68 void set_start(HeapWord* start) { _start = start; }
69 void set_end(HeapWord* end) { _end = end; }
70 void set_top(HeapWord* top) { _top = top; }
71 void set_pf_top(HeapWord* pf_top) { _pf_top = pf_top; }
72 void set_desired_size(size_t desired_size) { _desired_size = desired_size; }
73 void set_refill_waste_limit(size_t waste) { _refill_waste_limit = waste; }
74
75 size_t initial_refill_waste_limit() { return desired_size() / TLABRefillWasteFraction; }
76
77 static int target_refills() { return _target_refills; }
78 size_t initial_desired_size();
79
80 size_t remaining() const { return end() == NULL ? 0 : pointer_delta(hard_end(), top()); }
81
82 bool contains(HeapWord* obj, size_t size) { return (obj >= start()) && (obj + size <= top()); }
83
84 // Make parsable and release it.
85 void reset();
86
87 // Resize based on amount of allocation, etc.
88 void resize();
89
90 void invariants() const { assert(top() >= start() && top() <= end(), "invalid tlab"); }
91
92 void initialize(HeapWord* start, HeapWord* top, HeapWord* end);
93
94 void print_stats(const char* tag);
95
96 Thread* myThread();
97
98 // statistics
99
100 int number_of_refills() const { return _number_of_refills; }
101 int fast_refill_waste() const { return _fast_refill_waste; }
102 int slow_refill_waste() const { return _slow_refill_waste; }
103 int gc_waste() const { return _gc_waste; }
104 int slow_allocations() const { return _slow_allocations; }
105
106 static GlobalTLABStats* _global_stats;
107 static GlobalTLABStats* global_stats() { return _global_stats; }
108
109 public:
110 ThreadLocalAllocBuffer() : _allocation_fraction(TLABAllocationWeight), _allocated_before_last_gc(0) {
111 // do nothing. tlabs must be inited by initialize() calls
112 }
113
114 static size_t min_size() { return align_object_size(MinTLABSize / HeapWordSize) + alignment_reserve(); }
115 static size_t max_size() { assert(_max_size != 0, "max_size not set up"); return _max_size; }
116 static size_t max_size_in_bytes() { return max_size() * BytesPerWord; }
117 static void set_max_size(size_t max_size) { _max_size = max_size; }
118
119 HeapWord* start() const { return _start; }
120 HeapWord* end() const { return _end; }
121 HeapWord* hard_end() const { return _end + alignment_reserve(); }
122 HeapWord* top() const { return _top; }
123 HeapWord* pf_top() const { return _pf_top; }
124 size_t desired_size() const { return _desired_size; }
125 size_t used() const { return pointer_delta(top(), start()); }
126 size_t used_bytes() const { return pointer_delta(top(), start(), 1); }
127 size_t free() const { return pointer_delta(end(), top()); }
128 // Don't discard tlab if remaining space is larger than this.
129 size_t refill_waste_limit() const { return _refill_waste_limit; }
130
131 // Allocate size HeapWords. The memory is NOT initialized to zero.
132 inline HeapWord* allocate(size_t size);
133
134 // Undo last allocation.
135 inline bool undo_allocate(HeapWord* obj, size_t size);
136
137 // Reserve space at the end of TLAB
138 static size_t end_reserve() {
139 int reserve_size = typeArrayOopDesc::header_size(T_INT);
140 return MAX2(reserve_size, _reserve_for_allocation_prefetch);
141 }
142 static size_t alignment_reserve() { return align_object_size(end_reserve()); }
143 static size_t alignment_reserve_in_bytes() { return alignment_reserve() * HeapWordSize; }
144
145 // Return tlab size or remaining space in eden such that the
146 // space is large enough to hold obj_size and necessary fill space.
147 // Otherwise return 0;
148 inline size_t compute_size(size_t obj_size);
149
150 // Compute the minimal needed tlab size for the given object size.
151 static inline size_t compute_min_size(size_t obj_size);
152
153 // Record slow allocation
154 inline void record_slow_allocation(size_t obj_size);
155
156 // Initialization at startup
157 static void startup_initialization();
158
159 // Make an in-use tlab parsable, optionally retiring and/or zapping it.
160 void make_parsable(bool retire, bool zap = true);
161
162 // Retire in-use tlab before allocation of a new tlab
163 void clear_before_allocation();
164
165 // Accumulate statistics across all tlabs before gc
166 static void accumulate_statistics_before_gc();
167
168 // Resize tlabs for all threads
169 static void resize_all_tlabs();
170
171 void fill(HeapWord* start, HeapWord* top, size_t new_size);
172 void initialize();
173
174 static size_t refill_waste_limit_increment() { return TLABWasteIncrement; }
175
176 template <typename T> void addresses_do(T f) {
177 f(&_start);
178 f(&_top);
179 f(&_pf_top);
180 f(&_end);
181 }
182
183 // Code generation support
184 static ByteSize start_offset() { return byte_offset_of(ThreadLocalAllocBuffer, _start); }
185 static ByteSize end_offset() { return byte_offset_of(ThreadLocalAllocBuffer, _end ); }
186 static ByteSize top_offset() { return byte_offset_of(ThreadLocalAllocBuffer, _top ); }
187 static ByteSize pf_top_offset() { return byte_offset_of(ThreadLocalAllocBuffer, _pf_top ); }
188 static ByteSize size_offset() { return byte_offset_of(ThreadLocalAllocBuffer, _desired_size ); }
189 static ByteSize refill_waste_limit_offset() { return byte_offset_of(ThreadLocalAllocBuffer, _refill_waste_limit ); }
190
191 static ByteSize number_of_refills_offset() { return byte_offset_of(ThreadLocalAllocBuffer, _number_of_refills ); }
192 static ByteSize fast_refill_waste_offset() { return byte_offset_of(ThreadLocalAllocBuffer, _fast_refill_waste ); }
193 static ByteSize slow_allocations_offset() { return byte_offset_of(ThreadLocalAllocBuffer, _slow_allocations ); }
194
195 void verify();
196 };
197
198 class GlobalTLABStats: public CHeapObj<mtThread> {
199 private:
200
201 // Accumulate perfdata in private variables because
202 // PerfData should be write-only for security reasons
203 // (see perfData.hpp)
204 unsigned _allocating_threads;
205 unsigned _total_refills;
206 unsigned _max_refills;
207 size_t _total_allocation;
208 size_t _total_gc_waste;
209 size_t _max_gc_waste;
210 size_t _total_slow_refill_waste;
211 size_t _max_slow_refill_waste;
212 size_t _total_fast_refill_waste;
213 size_t _max_fast_refill_waste;
214 unsigned _total_slow_allocations;
215 unsigned _max_slow_allocations;
216
217 PerfVariable* _perf_allocating_threads;
218 PerfVariable* _perf_total_refills;
219 PerfVariable* _perf_max_refills;
220 PerfVariable* _perf_allocation;
221 PerfVariable* _perf_gc_waste;
222 PerfVariable* _perf_max_gc_waste;
223 PerfVariable* _perf_slow_refill_waste;
224 PerfVariable* _perf_max_slow_refill_waste;
225 PerfVariable* _perf_fast_refill_waste;
226 PerfVariable* _perf_max_fast_refill_waste;
227 PerfVariable* _perf_slow_allocations;
228 PerfVariable* _perf_max_slow_allocations;
229
230 AdaptiveWeightedAverage _allocating_threads_avg;
231
232 public:
233 GlobalTLABStats();
234
235 // Initialize all counters
236 void initialize();
237
238 // Write all perf counters to the perf_counters
239 void publish();
240
241 void print();
242
243 // Accessors
244 unsigned allocating_threads_avg() {
245 return MAX2((unsigned)(_allocating_threads_avg.average() + 0.5), 1U);
246 }
247
248 size_t allocation() {
249 return _total_allocation;
250 }
251
252 // Update methods
253
254 void update_allocating_threads() {
255 _allocating_threads++;
256 }
257 void update_number_of_refills(unsigned value) {
258 _total_refills += value;
259 _max_refills = MAX2(_max_refills, value);
260 }
261 void update_allocation(size_t value) {
262 _total_allocation += value;
263 }
264 void update_gc_waste(size_t value) {
265 _total_gc_waste += value;
266 _max_gc_waste = MAX2(_max_gc_waste, value);
267 }
268 void update_fast_refill_waste(size_t value) {
269 _total_fast_refill_waste += value;
270 _max_fast_refill_waste = MAX2(_max_fast_refill_waste, value);
271 }
272 void update_slow_refill_waste(size_t value) {
273 _total_slow_refill_waste += value;
274 _max_slow_refill_waste = MAX2(_max_slow_refill_waste, value);
275 }
276 void update_slow_allocations(unsigned value) {
277 _total_slow_allocations += value;
278 _max_slow_allocations = MAX2(_max_slow_allocations, value);
279 }
280 };
281
282 #endif // SHARE_VM_GC_SHARED_THREADLOCALALLOCBUFFER_HPP