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