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 is_last_allocation(HeapWord* obj, size_t size) { return pointer_delta(top(), obj) == size; }
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 ); }
|
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 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 accumulate_statistics();
75 void initialize_statistics();
76
77 void set_start(HeapWord* start) { _start = start; }
78 void set_end(HeapWord* end) { _end = end; }
79 void set_allocation_end(HeapWord* ptr) { _allocation_end = ptr; }
80 void set_top(HeapWord* top) { _top = top; }
81 void set_pf_top(HeapWord* pf_top) { _pf_top = pf_top; }
82 void set_desired_size(size_t desired_size) { _desired_size = desired_size; }
83 void set_refill_waste_limit(size_t waste) { _refill_waste_limit = waste; }
84
85 size_t initial_refill_waste_limit() { return desired_size() / TLABRefillWasteFraction; }
86
87 static int target_refills() { return _target_refills; }
88 size_t initial_desired_size();
89
90 size_t remaining();
91
92 bool is_last_allocation(HeapWord* obj, size_t size) { return pointer_delta(top(), obj) == size; }
93
94 // Make parsable and release it.
95 void reset();
96
97 // Resize based on amount of allocation, etc.
98 void resize();
99
100 void invariants() const { assert(top() >= start() && top() <= end(), "invalid tlab"); }
101
102 void initialize(HeapWord* start, HeapWord* top, HeapWord* end);
103
104 void print_stats(const char* tag);
105
106 Thread* myThread();
107
108 // statistics
109
110 int number_of_refills() const { return _number_of_refills; }
111 int fast_refill_waste() const { return _fast_refill_waste; }
112 int slow_refill_waste() const { return _slow_refill_waste; }
113 int gc_waste() const { return _gc_waste; }
114 int slow_allocations() const { return _slow_allocations; }
115
116 static GlobalTLABStats* _global_stats;
117 static GlobalTLABStats* global_stats() { return _global_stats; }
118
119 public:
120 ThreadLocalAllocBuffer() : _allocation_fraction(TLABAllocationWeight), _allocated_before_last_gc(0) {
121 // do nothing. tlabs must be inited by initialize() calls
122 }
123
124 static size_t min_size() { return align_object_size(MinTLABSize / HeapWordSize) + alignment_reserve(); }
125 static size_t max_size() { assert(_max_size != 0, "max_size not set up"); return _max_size; }
126 static size_t max_size_in_bytes() { return max_size() * BytesPerWord; }
127 static void set_max_size(size_t max_size) { _max_size = max_size; }
128
129 HeapWord* start() const { return _start; }
130 HeapWord* end() const { return _end; }
131 HeapWord* top() const { return _top; }
132 HeapWord* hard_end();
133 HeapWord* pf_top() const { return _pf_top; }
134 size_t desired_size() const { return _desired_size; }
135 size_t used() const { return pointer_delta(top(), start()); }
136 size_t used_bytes() const { return pointer_delta(top(), start(), 1); }
137 size_t free() const { return pointer_delta(end(), top()); }
138 // Don't discard tlab if remaining space is larger than this.
139 size_t refill_waste_limit() const { return _refill_waste_limit; }
140 size_t bytes_since_last_sample_point() const { return _bytes_since_last_sample_point; }
141
142 // Allocate size HeapWords. The memory is NOT initialized to zero.
143 inline HeapWord* allocate(size_t size);
144 HeapWord* allocate_sampled_object(size_t size);
145
146 // Undo last allocation.
147 inline bool undo_allocate(HeapWord* obj, size_t size);
148
149 // Reserve space at the end of TLAB
150 static size_t end_reserve() {
151 int reserve_size = typeArrayOopDesc::header_size(T_INT);
152 return MAX2(reserve_size, _reserve_for_allocation_prefetch);
153 }
154 static size_t alignment_reserve() { return align_object_size(end_reserve()); }
155 static size_t alignment_reserve_in_bytes() { return alignment_reserve() * HeapWordSize; }
156
157 // Return tlab size or remaining space in eden such that the
158 // space is large enough to hold obj_size and necessary fill space.
159 // Otherwise return 0;
160 inline size_t compute_size(size_t obj_size);
161
162 // Compute the minimal needed tlab size for the given object size.
163 static inline size_t compute_min_size(size_t obj_size);
164
165 // Record slow allocation
166 inline void record_slow_allocation(size_t obj_size);
167
168 // Initialization at startup
169 static void startup_initialization();
170
171 // Make an in-use tlab parsable, optionally retiring and/or zapping it.
172 void make_parsable(bool retire, bool zap = true);
173
174 // Retire in-use tlab before allocation of a new tlab
175 void clear_before_allocation();
176
177 // Accumulate statistics across all tlabs before gc
178 static void accumulate_statistics_before_gc();
179
180 // Resize tlabs for all threads
181 static void resize_all_tlabs();
182
183 void fill(HeapWord* start, HeapWord* top, size_t new_size);
184 void initialize();
185
186 void set_back_allocation_end();
187 void set_sample_end();
188
189 static size_t refill_waste_limit_increment() { return TLABWasteIncrement; }
190
191 template <typename T> void addresses_do(T f) {
192 f(&_start);
193 f(&_top);
194 f(&_pf_top);
195 f(&_end);
196 }
197
198 // Code generation support
199 static ByteSize start_offset() { return byte_offset_of(ThreadLocalAllocBuffer, _start); }
200 static ByteSize end_offset() { return byte_offset_of(ThreadLocalAllocBuffer, _end ); }
201 static ByteSize top_offset() { return byte_offset_of(ThreadLocalAllocBuffer, _top ); }
202 static ByteSize pf_top_offset() { return byte_offset_of(ThreadLocalAllocBuffer, _pf_top ); }
203 static ByteSize size_offset() { return byte_offset_of(ThreadLocalAllocBuffer, _desired_size ); }
204 static ByteSize refill_waste_limit_offset() { return byte_offset_of(ThreadLocalAllocBuffer, _refill_waste_limit ); }
205
206 static ByteSize number_of_refills_offset() { return byte_offset_of(ThreadLocalAllocBuffer, _number_of_refills ); }
207 static ByteSize fast_refill_waste_offset() { return byte_offset_of(ThreadLocalAllocBuffer, _fast_refill_waste ); }
|