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