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 ThreadLocalAllocStats; 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 and allocation_end 42 // fields. 43 // allocation_end contains the real end of the tlab allocation, 44 // whereas 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* _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 size_t _allocated_size; 71 72 AdaptiveWeightedAverage _allocation_fraction; // fraction of eden allocated in tlabs 73 74 void reset_statistics(); 75 76 void set_start(HeapWord* start) { _start = start; } 77 void set_end(HeapWord* end) { _end = 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 void invariants() const { assert(top() >= start() && top() <= end(), "invalid tlab"); } 95 96 void initialize(HeapWord* start, HeapWord* top, HeapWord* end); 97 98 void insert_filler(); 99 100 void accumulate_and_reset_statistics(ThreadLocalAllocStats* stats); 101 102 void print_stats(const char* tag); 103 104 Thread* thread(); 105 106 // statistics 107 108 int number_of_refills() const { return _number_of_refills; } 109 int fast_refill_waste() const { return _fast_refill_waste; } 110 int slow_refill_waste() const { return _slow_refill_waste; } 111 int gc_waste() const { return _gc_waste; } 112 int slow_allocations() const { return _slow_allocations; } 113 114 public: 115 ThreadLocalAllocBuffer() : _allocated_before_last_gc(0), _allocation_fraction(TLABAllocationWeight) { 116 // do nothing. tlabs must be inited by initialize() calls 117 } 118 119 static size_t min_size() { return align_object_size(MinTLABSize / HeapWordSize) + alignment_reserve(); } 120 static size_t max_size() { assert(_max_size != 0, "max_size not set up"); return _max_size; } 121 static size_t max_size_in_bytes() { return max_size() * BytesPerWord; } 122 static void set_max_size(size_t max_size) { _max_size = max_size; } 123 124 HeapWord* start() const { return _start; } 125 HeapWord* end() const { return _end; } 126 HeapWord* top() const { return _top; } 127 HeapWord* hard_end(); 128 HeapWord* pf_top() const { return _pf_top; } 129 size_t desired_size() const { return _desired_size; } 130 size_t used() const { return pointer_delta(top(), start()); } 131 size_t used_bytes() const { return pointer_delta(top(), start(), 1); } 132 size_t free() const { return pointer_delta(end(), top()); } 133 // Don't discard tlab if remaining space is larger than this. 134 size_t refill_waste_limit() const { return _refill_waste_limit; } 135 size_t bytes_since_last_sample_point() const { return _bytes_since_last_sample_point; } 136 137 // Allocate size HeapWords. The memory is NOT initialized to zero. 138 inline HeapWord* allocate(size_t size); 139 140 // Reserve space at the end of TLAB 141 static size_t end_reserve() { 142 int reserve_size = typeArrayOopDesc::header_size(T_INT); 143 return MAX2(reserve_size, _reserve_for_allocation_prefetch); 144 } 145 static size_t alignment_reserve() { return align_object_size(end_reserve()); } 146 static size_t alignment_reserve_in_bytes() { return alignment_reserve() * HeapWordSize; } 147 148 // Return tlab size or remaining space in eden such that the 149 // space is large enough to hold obj_size and necessary fill space. 150 // Otherwise return 0; 151 inline size_t compute_size(size_t obj_size); 152 153 // Compute the minimal needed tlab size for the given object size. 154 static inline size_t compute_min_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. 163 void make_parsable(); 164 165 // Retire an in-use tlab and optionally collect statistics. 166 void retire(ThreadLocalAllocStats* stats = NULL); 167 168 // Retire in-use tlab before allocation of a new tlab 169 void retire_before_allocation(); 170 171 // Resize based on amount of allocation, etc. 172 void resize(); 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 template <typename T> void addresses_do(T f) { 183 f(&_start); 184 f(&_top); 185 f(&_pf_top); 186 f(&_end); 187 f(&_allocation_end); 188 } 189 190 // Code generation support 191 static ByteSize start_offset() { return byte_offset_of(ThreadLocalAllocBuffer, _start); } 192 static ByteSize end_offset() { return byte_offset_of(ThreadLocalAllocBuffer, _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); } 195 196 void verify(); 197 }; 198 199 class ThreadLocalAllocStats : public StackObj { 200 private: 201 static PerfVariable* _perf_allocating_threads; 202 static PerfVariable* _perf_total_refills; 203 static PerfVariable* _perf_max_refills; 204 static PerfVariable* _perf_total_allocations; 205 static PerfVariable* _perf_total_gc_waste; 206 static PerfVariable* _perf_max_gc_waste; 207 static PerfVariable* _perf_total_slow_refill_waste; 208 static PerfVariable* _perf_max_slow_refill_waste; 209 static PerfVariable* _perf_total_fast_refill_waste; 210 static PerfVariable* _perf_max_fast_refill_waste; 211 static PerfVariable* _perf_total_slow_allocations; 212 static PerfVariable* _perf_max_slow_allocations; 213 214 static AdaptiveWeightedAverage _allocating_threads_avg; 215 216 unsigned int _allocating_threads; 217 unsigned int _total_refills; 218 unsigned int _max_refills; 219 size_t _total_allocations; 220 size_t _total_gc_waste; 221 size_t _max_gc_waste; 222 size_t _total_fast_refill_waste; 223 size_t _max_fast_refill_waste; 224 size_t _total_slow_refill_waste; 225 size_t _max_slow_refill_waste; 226 unsigned int _total_slow_allocations; 227 unsigned int _max_slow_allocations; 228 229 public: 230 static void initialize(); 231 static unsigned int allocating_threads_avg(); 232 233 ThreadLocalAllocStats(); 234 235 void update_fast_allocations(unsigned int refills, 236 size_t allocations, 237 size_t gc_waste, 238 size_t fast_refill_waste, 239 size_t slow_refill_waste); 240 void update_slow_allocations(unsigned int allocations); 241 void update(const ThreadLocalAllocStats& other); 242 243 void reset(); 244 void publish(); 245 }; 246 247 #endif // SHARE_VM_GC_SHARED_THREADLOCALALLOCBUFFER_HPP