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 #include "precompiled.hpp"
26 #include "gc/g1/g1CollectedHeap.inline.hpp"
27 #include "gc/g1/g1ErgoVerbose.hpp"
28 #include "gc/g1/g1IHOPControl.hpp"
29
30 G1IHOPControl::G1IHOPControl(double initial_ihop_percent, size_t target_occupancy) :
31 _initial_ihop_percent(initial_ihop_percent),
32 _target_occupancy(target_occupancy),
33 _last_allocated_bytes(0),
34 _last_allocation_time_s(0.0)
35 {
36 assert(_initial_ihop_percent >= 0.0 && _initial_ihop_percent <= 100.0, "Initial IHOP value must be between 0 and 100 but is %.3f", initial_ihop_percent);
37 }
38
39 void G1IHOPControl::update_allocation_info(double allocation_time_s, size_t allocated_bytes, size_t additional_buffer_size) {
40 assert(allocation_time_s >= 0.0, "Allocation time must be positive but is %.3f", allocation_time_s);
41
42 _last_allocation_time_s = allocation_time_s;
43 _last_allocated_bytes = allocated_bytes;
44 }
45
46 void G1IHOPControl::print() {
47 size_t cur_conc_mark_start_threshold = get_conc_mark_start_threshold();
48 ergo_verbose6(ErgoIHOP,
87 ctrl.update_allocation_info(100.0, 100, 100);
88 threshold = ctrl.get_conc_mark_start_threshold();
89 assert(threshold == initial_ihop,
90 "Expected IHOP threshold of " SIZE_FORMAT " but is " SIZE_FORMAT, initial_ihop, threshold);
91
92 ctrl.update_marking_length(1000.0);
93 threshold = ctrl.get_conc_mark_start_threshold();
94 assert(threshold == initial_ihop,
95 "Expected IHOP threshold of " SIZE_FORMAT " but is " SIZE_FORMAT, initial_ihop, threshold);
96
97 // Whatever we pass, the IHOP value must stay the same.
98 test_update(&ctrl, 2, 10, 10, 3);
99 threshold = ctrl.get_conc_mark_start_threshold();
100 assert(threshold == initial_ihop,
101 "Expected IHOP threshold of " SIZE_FORMAT " but is " SIZE_FORMAT, initial_ihop, threshold);
102
103 test_update(&ctrl, 12, 10, 10, 3);
104 threshold = ctrl.get_conc_mark_start_threshold();
105 assert(threshold == initial_ihop,
106 "Expected IHOP threshold of " SIZE_FORMAT " but is " SIZE_FORMAT, initial_ihop, threshold);
107 }
108
109 void IHOP_test() {
110 G1StaticIHOPControl::test();
111 }
112 #endif
|
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 #include "precompiled.hpp"
26 #include "gc/g1/g1CollectedHeap.inline.hpp"
27 #include "gc/g1/g1ErgoVerbose.hpp"
28 #include "gc/g1/g1IHOPControl.hpp"
29 #include "gc/g1/g1Predictions.hpp"
30
31 G1IHOPControl::G1IHOPControl(double initial_ihop_percent, size_t target_occupancy) :
32 _initial_ihop_percent(initial_ihop_percent),
33 _target_occupancy(target_occupancy),
34 _last_allocated_bytes(0),
35 _last_allocation_time_s(0.0)
36 {
37 assert(_initial_ihop_percent >= 0.0 && _initial_ihop_percent <= 100.0, "Initial IHOP value must be between 0 and 100 but is %.3f", initial_ihop_percent);
38 }
39
40 void G1IHOPControl::update_allocation_info(double allocation_time_s, size_t allocated_bytes, size_t additional_buffer_size) {
41 assert(allocation_time_s >= 0.0, "Allocation time must be positive but is %.3f", allocation_time_s);
42
43 _last_allocation_time_s = allocation_time_s;
44 _last_allocated_bytes = allocated_bytes;
45 }
46
47 void G1IHOPControl::print() {
48 size_t cur_conc_mark_start_threshold = get_conc_mark_start_threshold();
49 ergo_verbose6(ErgoIHOP,
88 ctrl.update_allocation_info(100.0, 100, 100);
89 threshold = ctrl.get_conc_mark_start_threshold();
90 assert(threshold == initial_ihop,
91 "Expected IHOP threshold of " SIZE_FORMAT " but is " SIZE_FORMAT, initial_ihop, threshold);
92
93 ctrl.update_marking_length(1000.0);
94 threshold = ctrl.get_conc_mark_start_threshold();
95 assert(threshold == initial_ihop,
96 "Expected IHOP threshold of " SIZE_FORMAT " but is " SIZE_FORMAT, initial_ihop, threshold);
97
98 // Whatever we pass, the IHOP value must stay the same.
99 test_update(&ctrl, 2, 10, 10, 3);
100 threshold = ctrl.get_conc_mark_start_threshold();
101 assert(threshold == initial_ihop,
102 "Expected IHOP threshold of " SIZE_FORMAT " but is " SIZE_FORMAT, initial_ihop, threshold);
103
104 test_update(&ctrl, 12, 10, 10, 3);
105 threshold = ctrl.get_conc_mark_start_threshold();
106 assert(threshold == initial_ihop,
107 "Expected IHOP threshold of " SIZE_FORMAT " but is " SIZE_FORMAT, initial_ihop, threshold);
108 }
109 #endif
110
111 G1AdaptiveIHOPControl::G1AdaptiveIHOPControl(double ihop_percent,
112 size_t initial_target_occupancy,
113 G1Predictions const* predictor,
114 size_t heap_reserve_percent,
115 size_t heap_waste_percent) :
116 G1IHOPControl(ihop_percent, initial_target_occupancy),
117 _predictor(predictor),
118 // A sigma of 0.95 favors more recent samples.
119 _marking_times_s(10, 0.95),
120 _allocation_rate_s(10, 0.95),
121 _last_unrestrained_young_size(0),
122 _heap_reserve_percent(heap_reserve_percent),
123 _heap_waste_percent(heap_waste_percent)
124 {
125 }
126
127 size_t G1AdaptiveIHOPControl::actual_target_threshold() const {
128 // The actual target threshold takes the heap reserve and the expected waste in
129 // free space into account.
130 // _heap_reserve is that part of the total heap capacity that is reserved for
131 // eventual promotion failure.
132 // _heap_waste is the amount of space will never be reclaimed in any
133 // heap, so can not be used for allocation during marking and must always be
134 // considered.
135
136 double safe_total_heap_percentage = MIN2((double)(_heap_reserve_percent + _heap_waste_percent), 100.0);
137
138 return MIN2(
139 G1CollectedHeap::heap()->max_capacity() * (100.0 - safe_total_heap_percentage) / 100.0,
140 _target_occupancy * (100.0 - _heap_waste_percent) / 100.0
141 );
142 }
143
144 bool G1AdaptiveIHOPControl::have_enough_data_for_prediction() const {
145 return ((size_t)_marking_times_s.num() >= G1AdaptiveIHOPNumInitialSamples) &&
146 ((size_t)_allocation_rate_s.num() >= G1AdaptiveIHOPNumInitialSamples);
147 }
148
149 size_t G1AdaptiveIHOPControl::get_conc_mark_start_threshold() {
150 if (have_enough_data_for_prediction()) {
151 double pred_marking_time = _predictor->get_new_prediction(&_marking_times_s);
152 double pred_promotion_rate = _predictor->get_new_prediction(&_allocation_rate_s);
153
154 size_t predicted_needed_bytes_during_marking =
155 (pred_marking_time * pred_promotion_rate +
156 _last_unrestrained_young_size); // In reality we would need the maximum size of the young gen during marking. This is a conservative estimate.
157
158 size_t internal_threshold = actual_target_threshold();
159 size_t predicted_initiating_threshold = predicted_needed_bytes_during_marking < internal_threshold ?
160 internal_threshold - predicted_needed_bytes_during_marking :
161 0;
162 return predicted_initiating_threshold;
163 } else {
164 // Use the initial value.
165 return _initial_ihop_percent * _target_occupancy / 100.0;
166 }
167 }
168
169 void G1AdaptiveIHOPControl::update_allocation_info(double allocation_time_s, size_t allocated_bytes, size_t additional_buffer_size) {
170 assert(allocation_time_s >= 0.0, "Allocation time must be positive but is %.3f", allocation_time_s);
171 double allocation_rate = (double) allocated_bytes / allocation_time_s;
172 _allocation_rate_s.add(allocation_rate);
173
174 _last_allocation_bytes = allocated_bytes;
175 _last_unrestrained_young_size = additional_buffer_size;
176 }
177
178 void G1AdaptiveIHOPControl::update_marking_length(double marking_length_s) {
179 assert(marking_length_s >= 0.0, "Marking length must be larger than zero but is %.3f", marking_length_s);
180 _marking_times_s.add(marking_length_s);
181 }
182
183 void G1AdaptiveIHOPControl::print() {
184 ergo_verbose6(ErgoIHOP,
185 "basic information",
186 ergo_format_reason("value update")
187 ergo_format_byte_perc("threshold")
188 ergo_format_byte("target occupancy")
189 ergo_format_byte("current occupancy")
190 ergo_format_double("recent old gen allocation rate")
191 ergo_format_double("recent marking phase length"),
192 get_conc_mark_start_threshold(),
193 percent_of(get_conc_mark_start_threshold(), _target_occupancy),
194 _target_occupancy,
195 G1CollectedHeap::heap()->used(),
196 _allocation_rate_s.last(),
197 _marking_times_s.last()
198 );
199 size_t actual_target = actual_target_threshold();
200 ergo_verbose6(ErgoIHOP,
201 "adaptive IHOP information",
202 ergo_format_reason("value update")
203 ergo_format_byte_perc("threshold")
204 ergo_format_byte("internal target occupancy")
205 ergo_format_double("predicted old gen allocation rate")
206 ergo_format_double("predicted marking phase length")
207 ergo_format_str("prediction active"),
208 get_conc_mark_start_threshold(),
209 percent_of(get_conc_mark_start_threshold(), actual_target),
210 actual_target,
211 _predictor->get_new_prediction(&_allocation_rate_s),
212 _predictor->get_new_prediction(&_marking_times_s),
213 have_enough_data_for_prediction() ? "true" : "false"
214 );
215 }
216
217 #ifndef PRODUCT
218 void G1AdaptiveIHOPControl::test() {
219 size_t const initial_threshold = 45;
220 size_t const young_size = 10;
221 size_t const target_size = 100;
222
223 // The final IHOP value is always
224 // target_size - (young_size + alloc_amount/alloc_time * marking_time)
225
226 G1Predictions pred(0.95);
227 G1AdaptiveIHOPControl ctrl(initial_threshold, target_size, &pred, 0, 0);
228
229 // First "load".
230 size_t const alloc_time1 = 2;
231 size_t const alloc_amount1 = 10;
232 size_t const marking_time1 = 2;
233 size_t const settled_ihop1 = target_size - (young_size + alloc_amount1/alloc_time1 * marking_time1);
234
235 size_t threshold;
236 threshold = ctrl.get_conc_mark_start_threshold();
237 assert(threshold == initial_threshold,
238 "Expected IHOP threshold of " SIZE_FORMAT " but is " SIZE_FORMAT, initial_threshold, threshold);
239 for (size_t i = 0; i < G1AdaptiveIHOPNumInitialSamples - 1; i++) {
240 ctrl.update_allocation_info(alloc_time1, alloc_amount1, young_size);
241 ctrl.update_marking_length(marking_time1);
242 // Not enough data yet.
243 threshold = ctrl.get_conc_mark_start_threshold();
244 assert(threshold == initial_threshold,
245 "Expected IHOP threshold of " SIZE_FORMAT " but is " SIZE_FORMAT, initial_threshold, threshold);
246 }
247
248 test_update(&ctrl, alloc_time1, alloc_amount1, young_size, marking_time1);
249
250 threshold = ctrl.get_conc_mark_start_threshold();
251 assert(threshold == settled_ihop1,
252 "Expected IHOP threshold to settle at " SIZE_FORMAT " but is " SIZE_FORMAT, settled_ihop1, threshold);
253
254 // Second "load". A bit higher allocation rate.
255 size_t const alloc_time2 = 2;
256 size_t const alloc_amount2 = 30;
257 size_t const marking_time2 = 2;
258 size_t const settled_ihop2 = target_size - (young_size + alloc_amount2/alloc_time2 * marking_time2);
259
260 test_update(&ctrl, alloc_time2, alloc_amount2, young_size, marking_time2);
261
262 threshold = ctrl.get_conc_mark_start_threshold();
263 assert(threshold < settled_ihop1,
264 "Expected IHOP threshold to settle at a value lower than " SIZE_FORMAT " but is " SIZE_FORMAT, settled_ihop1, threshold);
265
266 // Third "load". Very high (impossible) allocation rate.
267 size_t const alloc_time3 = 1;
268 size_t const alloc_amount3 = 50;
269 size_t const marking_time3 = 2;
270 size_t const settled_ihop3 = 0;
271
272 test_update(&ctrl, alloc_time3, alloc_amount3, young_size, marking_time3);
273 threshold = ctrl.get_conc_mark_start_threshold();
274
275 assert(threshold == settled_ihop3,
276 "Expected IHOP threshold to settle at " SIZE_FORMAT " but is " SIZE_FORMAT, settled_ihop3, threshold);
277
278 // And back to some arbitrary value.
279 test_update(&ctrl, alloc_time2, alloc_amount2, young_size, marking_time2);
280
281 threshold = ctrl.get_conc_mark_start_threshold();
282 assert(threshold > settled_ihop3,
283 "Expected IHOP threshold to settle at value larger than " SIZE_FORMAT " but is " SIZE_FORMAT, settled_ihop3, threshold);
284 }
285
286 void IHOP_test() {
287 G1StaticIHOPControl::test();
288 }
289 #endif
|