|
0
|
1 /*
|
|
|
2 * Copyright 2002-2007 Sun Microsystems, Inc. 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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
|
|
|
20 * CA 95054 USA or visit www.sun.com if you need additional information or
|
|
|
21 * have any questions.
|
|
|
22 *
|
|
|
23 */
|
|
|
24
|
|
|
25 // This class keeps statistical information and computes the
|
|
|
26 // optimal free space for both the young and old generation
|
|
|
27 // based on current application characteristics (based on gc cost
|
|
|
28 // and application footprint).
|
|
|
29 //
|
|
|
30 // It also computes an optimal tenuring threshold between the young
|
|
|
31 // and old generations, so as to equalize the cost of collections
|
|
|
32 // of those generations, as well as optimial survivor space sizes
|
|
|
33 // for the young generation.
|
|
|
34 //
|
|
|
35 // While this class is specifically intended for a generational system
|
|
|
36 // consisting of a young gen (containing an Eden and two semi-spaces)
|
|
|
37 // and a tenured gen, as well as a perm gen for reflective data, it
|
|
|
38 // makes NO references to specific generations.
|
|
|
39 //
|
|
|
40 // 05/02/2003 Update
|
|
|
41 // The 1.5 policy makes use of data gathered for the costs of GC on
|
|
|
42 // specific generations. That data does reference specific
|
|
|
43 // generation. Also diagnostics specific to generations have
|
|
|
44 // been added.
|
|
|
45
|
|
|
46 // Forward decls
|
|
|
47 class elapsedTimer;
|
|
|
48
|
|
|
49 class PSAdaptiveSizePolicy : public AdaptiveSizePolicy {
|
|
|
50 friend class PSGCAdaptivePolicyCounters;
|
|
|
51 private:
|
|
|
52 // These values are used to record decisions made during the
|
|
|
53 // policy. For example, if the young generation was decreased
|
|
|
54 // to decrease the GC cost of minor collections the value
|
|
|
55 // decrease_young_gen_for_throughput_true is used.
|
|
|
56
|
|
|
57 // Last calculated sizes, in bytes, and aligned
|
|
|
58 // NEEDS_CLEANUP should use sizes.hpp, but it works in ints, not size_t's
|
|
|
59
|
|
|
60 // Time statistics
|
|
|
61 AdaptivePaddedAverage* _avg_major_pause;
|
|
|
62
|
|
|
63 // Footprint statistics
|
|
|
64 AdaptiveWeightedAverage* _avg_base_footprint;
|
|
|
65
|
|
|
66 // Statistical data gathered for GC
|
|
|
67 GCStats _gc_stats;
|
|
|
68
|
|
|
69 size_t _survivor_size_limit; // Limit in bytes of survivor size
|
|
|
70 const double _collection_cost_margin_fraction;
|
|
|
71
|
|
|
72 // Variable for estimating the major and minor pause times.
|
|
|
73 // These variables represent linear least-squares fits of
|
|
|
74 // the data.
|
|
|
75 // major pause time vs. old gen size
|
|
|
76 LinearLeastSquareFit* _major_pause_old_estimator;
|
|
|
77 // major pause time vs. young gen size
|
|
|
78 LinearLeastSquareFit* _major_pause_young_estimator;
|
|
|
79
|
|
|
80
|
|
|
81 // These record the most recent collection times. They
|
|
|
82 // are available as an alternative to using the averages
|
|
|
83 // for making ergonomic decisions.
|
|
|
84 double _latest_major_mutator_interval_seconds;
|
|
|
85
|
|
|
86 const size_t _intra_generation_alignment; // alignment for eden, survivors
|
|
|
87
|
|
|
88 const double _gc_minor_pause_goal_sec; // goal for maximum minor gc pause
|
|
|
89
|
|
|
90 // The amount of live data in the heap at the last full GC, used
|
|
|
91 // as a baseline to help us determine when we need to perform the
|
|
|
92 // next full GC.
|
|
|
93 size_t _live_at_last_full_gc;
|
|
|
94
|
|
|
95 // decrease/increase the old generation for minor pause time
|
|
|
96 int _change_old_gen_for_min_pauses;
|
|
|
97
|
|
|
98 // increase/decrease the young generation for major pause time
|
|
|
99 int _change_young_gen_for_maj_pauses;
|
|
|
100
|
|
|
101
|
|
|
102 // Flag indicating that the adaptive policy is ready to use
|
|
|
103 bool _old_gen_policy_is_ready;
|
|
|
104
|
|
|
105 // Changing the generation sizing depends on the data that is
|
|
|
106 // gathered about the effects of changes on the pause times and
|
|
|
107 // throughput. These variable count the number of data points
|
|
|
108 // gathered. The policy may use these counters as a threshhold
|
|
|
109 // for reliable data.
|
|
|
110 julong _young_gen_change_for_major_pause_count;
|
|
|
111
|
|
|
112 // To facilitate faster growth at start up, supplement the normal
|
|
|
113 // growth percentage for the young gen eden and the
|
|
|
114 // old gen space for promotion with these value which decay
|
|
|
115 // with increasing collections.
|
|
|
116 uint _young_gen_size_increment_supplement;
|
|
|
117 uint _old_gen_size_increment_supplement;
|
|
|
118
|
|
|
119 // The number of bytes absorbed from eden into the old gen by moving the
|
|
|
120 // boundary over live data.
|
|
|
121 size_t _bytes_absorbed_from_eden;
|
|
|
122
|
|
|
123 private:
|
|
|
124
|
|
|
125 // Accessors
|
|
|
126 AdaptivePaddedAverage* avg_major_pause() const { return _avg_major_pause; }
|
|
|
127 double gc_minor_pause_goal_sec() const { return _gc_minor_pause_goal_sec; }
|
|
|
128
|
|
|
129 // Change the young generation size to achieve a minor GC pause time goal
|
|
|
130 void adjust_for_minor_pause_time(bool is_full_gc,
|
|
|
131 size_t* desired_promo_size_ptr,
|
|
|
132 size_t* desired_eden_size_ptr);
|
|
|
133 // Change the generation sizes to achieve a GC pause time goal
|
|
|
134 // Returned sizes are not necessarily aligned.
|
|
|
135 void adjust_for_pause_time(bool is_full_gc,
|
|
|
136 size_t* desired_promo_size_ptr,
|
|
|
137 size_t* desired_eden_size_ptr);
|
|
|
138 // Change the generation sizes to achieve an application throughput goal
|
|
|
139 // Returned sizes are not necessarily aligned.
|
|
|
140 void adjust_for_throughput(bool is_full_gc,
|
|
|
141 size_t* desired_promo_size_ptr,
|
|
|
142 size_t* desired_eden_size_ptr);
|
|
|
143 // Change the generation sizes to achieve minimum footprint
|
|
|
144 // Returned sizes are not aligned.
|
|
|
145 size_t adjust_promo_for_footprint(size_t desired_promo_size,
|
|
|
146 size_t desired_total);
|
|
|
147 size_t adjust_eden_for_footprint(size_t desired_promo_size,
|
|
|
148 size_t desired_total);
|
|
|
149
|
|
|
150 // Size in bytes for an increment or decrement of eden.
|
|
|
151 virtual size_t eden_increment(size_t cur_eden, uint percent_change);
|
|
|
152 virtual size_t eden_decrement(size_t cur_eden);
|
|
|
153 size_t eden_decrement_aligned_down(size_t cur_eden);
|
|
|
154 size_t eden_increment_with_supplement_aligned_up(size_t cur_eden);
|
|
|
155
|
|
|
156 // Size in bytes for an increment or decrement of the promotion area
|
|
|
157 virtual size_t promo_increment(size_t cur_promo, uint percent_change);
|
|
|
158 virtual size_t promo_decrement(size_t cur_promo);
|
|
|
159 size_t promo_decrement_aligned_down(size_t cur_promo);
|
|
|
160 size_t promo_increment_with_supplement_aligned_up(size_t cur_promo);
|
|
|
161
|
|
|
162 // Decay the supplemental growth additive.
|
|
|
163 void decay_supplemental_growth(bool is_full_gc);
|
|
|
164
|
|
|
165 // Returns a change that has been scaled down. Result
|
|
|
166 // is not aligned. (If useful, move to some shared
|
|
|
167 // location.)
|
|
|
168 size_t scale_down(size_t change, double part, double total);
|
|
|
169
|
|
|
170 protected:
|
|
|
171 // Time accessors
|
|
|
172
|
|
|
173 // Footprint accessors
|
|
|
174 size_t live_space() const {
|
|
|
175 return (size_t)(avg_base_footprint()->average() +
|
|
|
176 avg_young_live()->average() +
|
|
|
177 avg_old_live()->average());
|
|
|
178 }
|
|
|
179 size_t free_space() const {
|
|
|
180 return _eden_size + _promo_size;
|
|
|
181 }
|
|
|
182
|
|
|
183 void set_promo_size(size_t new_size) {
|
|
|
184 _promo_size = new_size;
|
|
|
185 }
|
|
|
186 void set_survivor_size(size_t new_size) {
|
|
|
187 _survivor_size = new_size;
|
|
|
188 }
|
|
|
189
|
|
|
190 // Update estimators
|
|
|
191 void update_minor_pause_old_estimator(double minor_pause_in_ms);
|
|
|
192
|
|
|
193 virtual GCPolicyKind kind() const { return _gc_ps_adaptive_size_policy; }
|
|
|
194
|
|
|
195 public:
|
|
|
196 // Use by ASPSYoungGen and ASPSOldGen to limit boundary moving.
|
|
|
197 size_t eden_increment_aligned_up(size_t cur_eden);
|
|
|
198 size_t eden_increment_aligned_down(size_t cur_eden);
|
|
|
199 size_t promo_increment_aligned_up(size_t cur_promo);
|
|
|
200 size_t promo_increment_aligned_down(size_t cur_promo);
|
|
|
201
|
|
|
202 virtual size_t eden_increment(size_t cur_eden);
|
|
|
203 virtual size_t promo_increment(size_t cur_promo);
|
|
|
204
|
|
|
205 // Accessors for use by performance counters
|
|
|
206 AdaptivePaddedNoZeroDevAverage* avg_promoted() const {
|
|
|
207 return _gc_stats.avg_promoted();
|
|
|
208 }
|
|
|
209 AdaptiveWeightedAverage* avg_base_footprint() const {
|
|
|
210 return _avg_base_footprint;
|
|
|
211 }
|
|
|
212
|
|
|
213 // Input arguments are initial free space sizes for young and old
|
|
|
214 // generations, the initial survivor space size, the
|
|
|
215 // alignment values and the pause & throughput goals.
|
|
|
216 //
|
|
|
217 // NEEDS_CLEANUP this is a singleton object
|
|
|
218 PSAdaptiveSizePolicy(size_t init_eden_size,
|
|
|
219 size_t init_promo_size,
|
|
|
220 size_t init_survivor_size,
|
|
|
221 size_t intra_generation_alignment,
|
|
|
222 double gc_pause_goal_sec,
|
|
|
223 double gc_minor_pause_goal_sec,
|
|
|
224 uint gc_time_ratio);
|
|
|
225
|
|
|
226 // Methods indicating events of interest to the adaptive size policy,
|
|
|
227 // called by GC algorithms. It is the responsibility of users of this
|
|
|
228 // policy to call these methods at the correct times!
|
|
|
229 void major_collection_begin();
|
|
|
230 void major_collection_end(size_t amount_live, GCCause::Cause gc_cause);
|
|
|
231
|
|
|
232 //
|
|
|
233 void tenured_allocation(size_t size) {
|
|
|
234 _avg_pretenured->sample(size);
|
|
|
235 }
|
|
|
236
|
|
|
237 // Accessors
|
|
|
238 // NEEDS_CLEANUP should use sizes.hpp
|
|
|
239
|
|
|
240 size_t calculated_old_free_size_in_bytes() const {
|
|
|
241 return (size_t)(_promo_size + avg_promoted()->padded_average());
|
|
|
242 }
|
|
|
243
|
|
|
244 size_t average_old_live_in_bytes() const {
|
|
|
245 return (size_t) avg_old_live()->average();
|
|
|
246 }
|
|
|
247
|
|
|
248 size_t average_promoted_in_bytes() const {
|
|
|
249 return (size_t)avg_promoted()->average();
|
|
|
250 }
|
|
|
251
|
|
|
252 size_t padded_average_promoted_in_bytes() const {
|
|
|
253 return (size_t)avg_promoted()->padded_average();
|
|
|
254 }
|
|
|
255
|
|
|
256 int change_young_gen_for_maj_pauses() {
|
|
|
257 return _change_young_gen_for_maj_pauses;
|
|
|
258 }
|
|
|
259 void set_change_young_gen_for_maj_pauses(int v) {
|
|
|
260 _change_young_gen_for_maj_pauses = v;
|
|
|
261 }
|
|
|
262
|
|
|
263 int change_old_gen_for_min_pauses() {
|
|
|
264 return _change_old_gen_for_min_pauses;
|
|
|
265 }
|
|
|
266 void set_change_old_gen_for_min_pauses(int v) {
|
|
|
267 _change_old_gen_for_min_pauses = v;
|
|
|
268 }
|
|
|
269
|
|
|
270 // Return true if the old generation size was changed
|
|
|
271 // to try to reach a pause time goal.
|
|
|
272 bool old_gen_changed_for_pauses() {
|
|
|
273 bool result = _change_old_gen_for_maj_pauses != 0 ||
|
|
|
274 _change_old_gen_for_min_pauses != 0;
|
|
|
275 return result;
|
|
|
276 }
|
|
|
277
|
|
|
278 // Return true if the young generation size was changed
|
|
|
279 // to try to reach a pause time goal.
|
|
|
280 bool young_gen_changed_for_pauses() {
|
|
|
281 bool result = _change_young_gen_for_min_pauses != 0 ||
|
|
|
282 _change_young_gen_for_maj_pauses != 0;
|
|
|
283 return result;
|
|
|
284 }
|
|
|
285 // end flags for pause goal
|
|
|
286
|
|
|
287 // Return true if the old generation size was changed
|
|
|
288 // to try to reach a throughput goal.
|
|
|
289 bool old_gen_changed_for_throughput() {
|
|
|
290 bool result = _change_old_gen_for_throughput != 0;
|
|
|
291 return result;
|
|
|
292 }
|
|
|
293
|
|
|
294 // Return true if the young generation size was changed
|
|
|
295 // to try to reach a throughput goal.
|
|
|
296 bool young_gen_changed_for_throughput() {
|
|
|
297 bool result = _change_young_gen_for_throughput != 0;
|
|
|
298 return result;
|
|
|
299 }
|
|
|
300
|
|
|
301 int decrease_for_footprint() { return _decrease_for_footprint; }
|
|
|
302
|
|
|
303
|
|
|
304 // Accessors for estimators. The slope of the linear fit is
|
|
|
305 // currently all that is used for making decisions.
|
|
|
306
|
|
|
307 LinearLeastSquareFit* major_pause_old_estimator() {
|
|
|
308 return _major_pause_old_estimator;
|
|
|
309 }
|
|
|
310
|
|
|
311 LinearLeastSquareFit* major_pause_young_estimator() {
|
|
|
312 return _major_pause_young_estimator;
|
|
|
313 }
|
|
|
314
|
|
|
315
|
|
|
316 virtual void clear_generation_free_space_flags();
|
|
|
317
|
|
|
318 float major_pause_old_slope() { return _major_pause_old_estimator->slope(); }
|
|
|
319 float major_pause_young_slope() {
|
|
|
320 return _major_pause_young_estimator->slope();
|
|
|
321 }
|
|
|
322 float major_collection_slope() { return _major_collection_estimator->slope();}
|
|
|
323
|
|
|
324 bool old_gen_policy_is_ready() { return _old_gen_policy_is_ready; }
|
|
|
325
|
|
|
326 // Given the amount of live data in the heap, should we
|
|
|
327 // perform a Full GC?
|
|
|
328 bool should_full_GC(size_t live_in_old_gen);
|
|
|
329
|
|
|
330 // Calculates optimial free space sizes for both the old and young
|
|
|
331 // generations. Stores results in _eden_size and _promo_size.
|
|
|
332 // Takes current used space in all generations as input, as well
|
|
|
333 // as an indication if a full gc has just been performed, for use
|
|
|
334 // in deciding if an OOM error should be thrown.
|
|
|
335 void compute_generation_free_space(size_t young_live,
|
|
|
336 size_t eden_live,
|
|
|
337 size_t old_live,
|
|
|
338 size_t perm_live,
|
|
|
339 size_t cur_eden, // current eden in bytes
|
|
|
340 size_t max_old_gen_size,
|
|
|
341 size_t max_eden_size,
|
|
|
342 bool is_full_gc,
|
|
|
343 GCCause::Cause gc_cause);
|
|
|
344
|
|
|
345 // Calculates new survivor space size; returns a new tenuring threshold
|
|
|
346 // value. Stores new survivor size in _survivor_size.
|
|
|
347 int compute_survivor_space_size_and_threshold(bool is_survivor_overflow,
|
|
|
348 int tenuring_threshold,
|
|
|
349 size_t survivor_limit);
|
|
|
350
|
|
|
351 // Return the maximum size of a survivor space if the young generation were of
|
|
|
352 // size gen_size.
|
|
|
353 size_t max_survivor_size(size_t gen_size) {
|
|
|
354 // Never allow the target survivor size to grow more than MinSurvivorRatio
|
|
|
355 // of the young generation size. We cannot grow into a two semi-space
|
|
|
356 // system, with Eden zero sized. Even if the survivor space grows, from()
|
|
|
357 // might grow by moving the bottom boundary "down" -- so from space will
|
|
|
358 // remain almost full anyway (top() will be near end(), but there will be a
|
|
|
359 // large filler object at the bottom).
|
|
|
360 const size_t sz = gen_size / MinSurvivorRatio;
|
|
|
361 const size_t alignment = _intra_generation_alignment;
|
|
|
362 return sz > alignment ? align_size_down(sz, alignment) : alignment;
|
|
|
363 }
|
|
|
364
|
|
|
365 size_t live_at_last_full_gc() {
|
|
|
366 return _live_at_last_full_gc;
|
|
|
367 }
|
|
|
368
|
|
|
369 size_t bytes_absorbed_from_eden() const { return _bytes_absorbed_from_eden; }
|
|
|
370 void reset_bytes_absorbed_from_eden() { _bytes_absorbed_from_eden = 0; }
|
|
|
371
|
|
|
372 void set_bytes_absorbed_from_eden(size_t val) {
|
|
|
373 _bytes_absorbed_from_eden = val;
|
|
|
374 }
|
|
|
375
|
|
|
376 // Update averages that are always used (even
|
|
|
377 // if adaptive sizing is turned off).
|
|
|
378 void update_averages(bool is_survivor_overflow,
|
|
|
379 size_t survived,
|
|
|
380 size_t promoted);
|
|
|
381
|
|
|
382 // Printing support
|
|
|
383 virtual bool print_adaptive_size_policy_on(outputStream* st) const;
|
|
|
384 };
|
