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 // 41 // Heap sampling is performed via the end/actual_end fields. 42 // actual_end contains the real end of the tlab allocation, 43 // whereas end can be set to an arbitrary spot in the tlab to 44 // trip the return and sample the allocation. 45 // slow_path_end is used to track if a fast tlab refill occured 46 // between slowpath calls. 47 class ThreadLocalAllocBuffer: public CHeapObj<mtThread> { 48 friend class VMStructs; 49 friend class JVMCIVMStructs; 50 private: 51 HeapWord* _start; // address of TLAB 52 HeapWord* _top; // address after last allocation 53 HeapWord* _pf_top; // allocation prefetch watermark 54 HeapWord* _current_end; // allocation end (can be the sampling end point or _allocation_end) 55 HeapWord* _allocation_end; // end for allocations (actual TLAB end, excluding alignment_reserve) 56 HeapWord* _last_slow_path_end; // last address for slow_path_end (as opposed to _allocation_end) 57 58 size_t _desired_size; // desired size (including alignment_reserve) 59 size_t _refill_waste_limit; // hold onto tlab if free() is larger than this 60 size_t _allocated_before_last_gc; // total bytes allocated up until the last gc 61 size_t _bytes_until_sample; // bytes until sample. 62 63 static size_t _max_size; // maximum size of any TLAB 64 static int _reserve_for_allocation_prefetch; // Reserve at the end of the TLAB 65 static unsigned _target_refills; // expected number of refills between GCs 66 67 unsigned _number_of_refills; 68 unsigned _fast_refill_waste; 69 unsigned _slow_refill_waste; 70 unsigned _gc_waste; 71 unsigned _slow_allocations; 72 73 AdaptiveWeightedAverage _allocation_fraction; // fraction of eden allocated in tlabs 74 75 void accumulate_statistics(); 76 void initialize_statistics(); 77 78 void set_start(HeapWord* start) { _start = start; } 79 void set_current_end(HeapWord* current_end) { _current_end = current_end; } 80 void set_allocation_end(HeapWord* ptr) { _allocation_end = ptr; } 81 void set_last_slow_path_end(HeapWord* ptr) { _last_slow_path_end = ptr; } 82 void set_top(HeapWord* top) { _top = top; } 83 void set_pf_top(HeapWord* pf_top) { _pf_top = pf_top; } 84 void set_desired_size(size_t desired_size) { _desired_size = desired_size; } 85 void set_refill_waste_limit(size_t waste) { _refill_waste_limit = waste; } 86 void set_bytes_until_sample(size_t bytes) { _bytes_until_sample = bytes; } 87 88 size_t initial_refill_waste_limit() { return desired_size() / TLABRefillWasteFraction; } 89 90 static int target_refills() { return _target_refills; } 91 size_t initial_desired_size(); 92 93 size_t remaining(); 94 95 void set_sample_end(); 96 void update_end_pointers(); 97 98 // Make parsable and release it. 99 void reset(); 100 101 // Resize based on amount of allocation, etc. 102 void resize(); 103 104 void invariants() const { assert(top() >= start() && top() <= current_end(), "invalid tlab"); } 105 106 void initialize(HeapWord* start, HeapWord* top, HeapWord* end); 107 108 void print_stats(const char* tag); 109 110 Thread* myThread(); 111 112 // statistics 113 114 int number_of_refills() const { return _number_of_refills; } 115 int fast_refill_waste() const { return _fast_refill_waste; } 116 int slow_refill_waste() const { return _slow_refill_waste; } 117 int gc_waste() const { return _gc_waste; } 118 int slow_allocations() const { return _slow_allocations; } 119 120 static GlobalTLABStats* _global_stats; 121 static GlobalTLABStats* global_stats() { return _global_stats; } 122 123 public: 124 ThreadLocalAllocBuffer() : _allocation_fraction(TLABAllocationWeight), _allocated_before_last_gc(0) { 125 // do nothing. tlabs must be inited by initialize() calls 126 } 127 128 static size_t min_size() { return align_object_size(MinTLABSize / HeapWordSize) + alignment_reserve(); } 129 static size_t max_size() { assert(_max_size != 0, "max_size not set up"); return _max_size; } 130 static size_t max_size_in_bytes() { return max_size() * BytesPerWord; } 131 static void set_max_size(size_t max_size) { _max_size = max_size; } 132 133 HeapWord* start() const { return _start; } 134 HeapWord* current_end() const { return _current_end; } 135 HeapWord* top() const { return _top; } 136 HeapWord* reserved_end(); 137 HeapWord* pf_top() const { return _pf_top; } 138 size_t desired_size() const { return _desired_size; } 139 size_t used() const { return pointer_delta(top(), start()); } 140 size_t used_bytes() const { return pointer_delta(top(), start(), 1); } 141 size_t free() const { return pointer_delta(current_end(), top()); } 142 // Don't discard tlab if remaining space is larger than this. 143 size_t refill_waste_limit() const { return _refill_waste_limit; } 144 145 // Allocate size HeapWords. The memory is NOT initialized to zero. 146 inline HeapWord* allocate(size_t size); 147 148 // Reserve space at the end of TLAB 149 static size_t end_reserve() { 150 int reserve_size = typeArrayOopDesc::header_size(T_INT); 151 return MAX2(reserve_size, _reserve_for_allocation_prefetch); 152 } 153 static size_t alignment_reserve() { return align_object_size(end_reserve()); } 154 static size_t alignment_reserve_in_bytes() { return alignment_reserve() * HeapWordSize; } 155 156 // Return tlab size or remaining space in eden such that the 157 // space is large enough to hold obj_size and necessary fill space. 158 // Otherwise return 0; 159 inline size_t compute_size(size_t obj_size); 160 161 // Record slow allocation 162 inline void record_slow_allocation(size_t obj_size); 163 164 // Initialization at startup 165 static void startup_initialization(); 166 167 // Make an in-use tlab parsable, optionally retiring and/or zapping it. 168 void make_parsable(bool retire, bool zap = true); 169 170 // Retire in-use tlab before allocation of a new tlab 171 void clear_before_allocation(); 172 173 // Accumulate statistics across all tlabs before gc 174 static void accumulate_statistics_before_gc(); 175 176 // Resize tlabs for all threads 177 static void resize_all_tlabs(); 178 179 void fill(HeapWord* start, HeapWord* top, size_t new_size); 180 void initialize(); 181 182 void pick_next_sample(size_t diff = 0); 183 void set_back_allocation_end(); 184 void update_tlab_sample_point(size_t size_in_bytes); 185 void handle_sample(Thread* thread, HeapWord* result, size_t size_in_bytes); 186 bool should_sample() { return _bytes_until_sample == 0; } 187 188 static size_t refill_waste_limit_increment() { return TLABWasteIncrement; } 189 190 // Code generation support 191 static ByteSize start_offset() { return byte_offset_of(ThreadLocalAllocBuffer, _start); } 192 static ByteSize current_end_offset() { return byte_offset_of(ThreadLocalAllocBuffer, _current_end ); } 193 static ByteSize top_offset() { return byte_offset_of(ThreadLocalAllocBuffer, _top ); } 194 static ByteSize pf_top_offset() { return byte_offset_of(ThreadLocalAllocBuffer, _pf_top ); } 195 static ByteSize size_offset() { return byte_offset_of(ThreadLocalAllocBuffer, _desired_size ); } 196 static ByteSize refill_waste_limit_offset() { return byte_offset_of(ThreadLocalAllocBuffer, _refill_waste_limit ); } 197 198 static ByteSize number_of_refills_offset() { return byte_offset_of(ThreadLocalAllocBuffer, _number_of_refills ); } 199 static ByteSize fast_refill_waste_offset() { return byte_offset_of(ThreadLocalAllocBuffer, _fast_refill_waste ); } 200 static ByteSize slow_allocations_offset() { return byte_offset_of(ThreadLocalAllocBuffer, _slow_allocations ); } 201 202 void verify(); 203 }; 204 205 class GlobalTLABStats: public CHeapObj<mtThread> { 206 private: 207 208 // Accumulate perfdata in private variables because 209 // PerfData should be write-only for security reasons 210 // (see perfData.hpp) 211 unsigned _allocating_threads; 212 unsigned _total_refills; 213 unsigned _max_refills; 214 size_t _total_allocation; 215 size_t _total_gc_waste; 216 size_t _max_gc_waste; 217 size_t _total_slow_refill_waste; 218 size_t _max_slow_refill_waste; 219 size_t _total_fast_refill_waste; 220 size_t _max_fast_refill_waste; 221 unsigned _total_slow_allocations; 222 unsigned _max_slow_allocations; 223 224 PerfVariable* _perf_allocating_threads; 225 PerfVariable* _perf_total_refills; 226 PerfVariable* _perf_max_refills; 227 PerfVariable* _perf_allocation; 228 PerfVariable* _perf_gc_waste; 229 PerfVariable* _perf_max_gc_waste; 230 PerfVariable* _perf_slow_refill_waste; 231 PerfVariable* _perf_max_slow_refill_waste; 232 PerfVariable* _perf_fast_refill_waste; 233 PerfVariable* _perf_max_fast_refill_waste; 234 PerfVariable* _perf_slow_allocations; 235 PerfVariable* _perf_max_slow_allocations; 236 237 AdaptiveWeightedAverage _allocating_threads_avg; 238 239 public: 240 GlobalTLABStats(); 241 242 // Initialize all counters 243 void initialize(); 244 245 // Write all perf counters to the perf_counters 246 void publish(); 247 248 void print(); 249 250 // Accessors 251 unsigned allocating_threads_avg() { 252 return MAX2((unsigned)(_allocating_threads_avg.average() + 0.5), 1U); 253 } 254 255 size_t allocation() { 256 return _total_allocation; 257 } 258 259 // Update methods 260 261 void update_allocating_threads() { 262 _allocating_threads++; 263 } 264 void update_number_of_refills(unsigned value) { 265 _total_refills += value; 266 _max_refills = MAX2(_max_refills, value); 267 } 268 void update_allocation(size_t value) { 269 _total_allocation += value; 270 } 271 void update_gc_waste(size_t value) { 272 _total_gc_waste += value; 273 _max_gc_waste = MAX2(_max_gc_waste, value); 274 } 275 void update_fast_refill_waste(size_t value) { 276 _total_fast_refill_waste += value; 277 _max_fast_refill_waste = MAX2(_max_fast_refill_waste, value); 278 } 279 void update_slow_refill_waste(size_t value) { 280 _total_slow_refill_waste += value; 281 _max_slow_refill_waste = MAX2(_max_slow_refill_waste, value); 282 } 283 void update_slow_allocations(unsigned value) { 284 _total_slow_allocations += value; 285 _max_slow_allocations = MAX2(_max_slow_allocations, value); 286 } 287 }; 288 289 #endif // SHARE_VM_GC_SHARED_THREADLOCALALLOCBUFFER_HPP