g1MonitoringSupport.cpp revision 8413:92457dfb91bd 
1/*
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3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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5 * This code is free software; you can redistribute it and/or modify it
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11 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
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17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
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24
25#include "precompiled.hpp"
26#include "gc/g1/g1CollectedHeap.inline.hpp"
27#include "gc/g1/g1CollectorPolicy.hpp"
28#include "gc/g1/g1MonitoringSupport.hpp"
29
30G1GenerationCounters::G1GenerationCounters(G1MonitoringSupport* g1mm,
31                                           const char* name,
32                                           int ordinal, int spaces,
33                                           size_t min_capacity,
34                                           size_t max_capacity,
35                                           size_t curr_capacity)
36  : GenerationCounters(name, ordinal, spaces, min_capacity,
37                       max_capacity, curr_capacity), _g1mm(g1mm) { }
38
39// We pad the capacity three times given that the young generation
40// contains three spaces (eden and two survivors).
41G1YoungGenerationCounters::G1YoungGenerationCounters(G1MonitoringSupport* g1mm,
42                                                     const char* name)
43  : G1GenerationCounters(g1mm, name, 0 /* ordinal */, 3 /* spaces */,
44               G1MonitoringSupport::pad_capacity(0, 3) /* min_capacity */,
45               G1MonitoringSupport::pad_capacity(g1mm->young_gen_max(), 3),
46               G1MonitoringSupport::pad_capacity(0, 3) /* curr_capacity */) {
47  if (UsePerfData) {
48    update_all();
49  }
50}
51
52G1OldGenerationCounters::G1OldGenerationCounters(G1MonitoringSupport* g1mm,
53                                                 const char* name)
54  : G1GenerationCounters(g1mm, name, 1 /* ordinal */, 1 /* spaces */,
55               G1MonitoringSupport::pad_capacity(0) /* min_capacity */,
56               G1MonitoringSupport::pad_capacity(g1mm->old_gen_max()),
57               G1MonitoringSupport::pad_capacity(0) /* curr_capacity */) {
58  if (UsePerfData) {
59    update_all();
60  }
61}
62
63void G1YoungGenerationCounters::update_all() {
64  size_t committed =
65            G1MonitoringSupport::pad_capacity(_g1mm->young_gen_committed(), 3);
66  _current_size->set_value(committed);
67}
68
69void G1OldGenerationCounters::update_all() {
70  size_t committed =
71            G1MonitoringSupport::pad_capacity(_g1mm->old_gen_committed());
72  _current_size->set_value(committed);
73}
74
75G1MonitoringSupport::G1MonitoringSupport(G1CollectedHeap* g1h) :
76  _g1h(g1h),
77  _incremental_collection_counters(NULL),
78  _full_collection_counters(NULL),
79  _old_collection_counters(NULL),
80  _old_space_counters(NULL),
81  _young_collection_counters(NULL),
82  _eden_counters(NULL),
83  _from_counters(NULL),
84  _to_counters(NULL),
85
86  _overall_reserved(0),
87  _overall_committed(0),    _overall_used(0),
88  _young_region_num(0),
89  _young_gen_committed(0),
90  _eden_committed(0),       _eden_used(0),
91  _survivor_committed(0),   _survivor_used(0),
92  _old_committed(0),        _old_used(0) {
93
94  _overall_reserved = g1h->max_capacity();
95  recalculate_sizes();
96
97  // Counters for GC collections
98  //
99  //  name "collector.0".  In a generational collector this would be the
100  // young generation collection.
101  _incremental_collection_counters =
102    new CollectorCounters("G1 incremental collections", 0);
103  //   name "collector.1".  In a generational collector this would be the
104  // old generation collection.
105  _full_collection_counters =
106    new CollectorCounters("G1 stop-the-world full collections", 1);
107
108  // timer sampling for all counters supporting sampling only update the
109  // used value.  See the take_sample() method.  G1 requires both used and
110  // capacity updated so sampling is not currently used.  It might
111  // be sufficient to update all counters in take_sample() even though
112  // take_sample() only returns "used".  When sampling was used, there
113  // were some anomolous values emitted which may have been the consequence
114  // of not updating all values simultaneously (i.e., see the calculation done
115  // in eden_space_used(), is it possible that the values used to
116  // calculate either eden_used or survivor_used are being updated by
117  // the collector when the sample is being done?).
118  const bool sampled = false;
119
120  // "Generation" and "Space" counters.
121  //
122  //  name "generation.1" This is logically the old generation in
123  // generational GC terms.  The "1, 1" parameters are for
124  // the n-th generation (=1) with 1 space.
125  // Counters are created from minCapacity, maxCapacity, and capacity
126  _old_collection_counters = new G1OldGenerationCounters(this, "old");
127
128  //  name  "generation.1.space.0"
129  // Counters are created from maxCapacity, capacity, initCapacity,
130  // and used.
131  _old_space_counters = new HSpaceCounters("space", 0 /* ordinal */,
132    pad_capacity(overall_reserved()) /* max_capacity */,
133    pad_capacity(old_space_committed()) /* init_capacity */,
134   _old_collection_counters);
135
136  //   Young collection set
137  //  name "generation.0".  This is logically the young generation.
138  //  The "0, 3" are parameters for the n-th generation (=0) with 3 spaces.
139  // See  _old_collection_counters for additional counters
140  _young_collection_counters = new G1YoungGenerationCounters(this, "young");
141
142  //  name "generation.0.space.0"
143  // See _old_space_counters for additional counters
144  _eden_counters = new HSpaceCounters("eden", 0 /* ordinal */,
145    pad_capacity(overall_reserved()) /* max_capacity */,
146    pad_capacity(eden_space_committed()) /* init_capacity */,
147    _young_collection_counters);
148
149  //  name "generation.0.space.1"
150  // See _old_space_counters for additional counters
151  // Set the arguments to indicate that this survivor space is not used.
152  _from_counters = new HSpaceCounters("s0", 1 /* ordinal */,
153    pad_capacity(0) /* max_capacity */,
154    pad_capacity(0) /* init_capacity */,
155    _young_collection_counters);
156
157  //  name "generation.0.space.2"
158  // See _old_space_counters for additional counters
159  _to_counters = new HSpaceCounters("s1", 2 /* ordinal */,
160    pad_capacity(overall_reserved()) /* max_capacity */,
161    pad_capacity(survivor_space_committed()) /* init_capacity */,
162    _young_collection_counters);
163
164  if (UsePerfData) {
165    // Given that this survivor space is not used, we update it here
166    // once to reflect that its used space is 0 so that we don't have to
167    // worry about updating it again later.
168    _from_counters->update_used(0);
169  }
170}
171
172void G1MonitoringSupport::recalculate_sizes() {
173  G1CollectedHeap* g1 = g1h();
174
175  // Recalculate all the sizes from scratch. We assume that this is
176  // called at a point where no concurrent updates to the various
177  // values we read here are possible (i.e., at a STW phase at the end
178  // of a GC).
179
180  uint young_list_length = g1->young_list()->length();
181  uint survivor_list_length = g1->g1_policy()->recorded_survivor_regions();
182  assert(young_list_length >= survivor_list_length, "invariant");
183  uint eden_list_length = young_list_length - survivor_list_length;
184  // Max length includes any potential extensions to the young gen
185  // we'll do when the GC locker is active.
186  uint young_list_max_length = g1->g1_policy()->young_list_max_length();
187  assert(young_list_max_length >= survivor_list_length, "invariant");
188  uint eden_list_max_length = young_list_max_length - survivor_list_length;
189
190  _overall_used = g1->used_unlocked();
191  _eden_used = (size_t) eden_list_length * HeapRegion::GrainBytes;
192  _survivor_used = (size_t) survivor_list_length * HeapRegion::GrainBytes;
193  _young_region_num = young_list_length;
194  _old_used = subtract_up_to_zero(_overall_used, _eden_used + _survivor_used);
195
196  // First calculate the committed sizes that can be calculated independently.
197  _survivor_committed = _survivor_used;
198  _old_committed = HeapRegion::align_up_to_region_byte_size(_old_used);
199
200  // Next, start with the overall committed size.
201  _overall_committed = g1->capacity();
202  size_t committed = _overall_committed;
203
204  // Remove the committed size we have calculated so far (for the
205  // survivor and old space).
206  assert(committed >= (_survivor_committed + _old_committed), "sanity");
207  committed -= _survivor_committed + _old_committed;
208
209  // Next, calculate and remove the committed size for the eden.
210  _eden_committed = (size_t) eden_list_max_length * HeapRegion::GrainBytes;
211  // Somewhat defensive: be robust in case there are inaccuracies in
212  // the calculations
213  _eden_committed = MIN2(_eden_committed, committed);
214  committed -= _eden_committed;
215
216  // Finally, give the rest to the old space...
217  _old_committed += committed;
218  // ..and calculate the young gen committed.
219  _young_gen_committed = _eden_committed + _survivor_committed;
220
221  assert(_overall_committed ==
222         (_eden_committed + _survivor_committed + _old_committed),
223         "the committed sizes should add up");
224  // Somewhat defensive: cap the eden used size to make sure it
225  // never exceeds the committed size.
226  _eden_used = MIN2(_eden_used, _eden_committed);
227  // _survivor_committed and _old_committed are calculated in terms of
228  // the corresponding _*_used value, so the next two conditions
229  // should hold.
230  assert(_survivor_used <= _survivor_committed, "post-condition");
231  assert(_old_used <= _old_committed, "post-condition");
232}
233
234void G1MonitoringSupport::recalculate_eden_size() {
235  G1CollectedHeap* g1 = g1h();
236
237  // When a new eden region is allocated, only the eden_used size is
238  // affected (since we have recalculated everything else at the last GC).
239
240  uint young_region_num = g1h()->young_list()->length();
241  if (young_region_num > _young_region_num) {
242    uint diff = young_region_num - _young_region_num;
243    _eden_used += (size_t) diff * HeapRegion::GrainBytes;
244    // Somewhat defensive: cap the eden used size to make sure it
245    // never exceeds the committed size.
246    _eden_used = MIN2(_eden_used, _eden_committed);
247    _young_region_num = young_region_num;
248  }
249}
250
251void G1MonitoringSupport::update_sizes() {
252  recalculate_sizes();
253  if (UsePerfData) {
254    eden_counters()->update_capacity(pad_capacity(eden_space_committed()));
255    eden_counters()->update_used(eden_space_used());
256    // only the to survivor space (s1) is active, so we don't need to
257    // update the counters for the from survivor space (s0)
258    to_counters()->update_capacity(pad_capacity(survivor_space_committed()));
259    to_counters()->update_used(survivor_space_used());
260    old_space_counters()->update_capacity(pad_capacity(old_space_committed()));
261    old_space_counters()->update_used(old_space_used());
262    old_collection_counters()->update_all();
263    young_collection_counters()->update_all();
264    MetaspaceCounters::update_performance_counters();
265    CompressedClassSpaceCounters::update_performance_counters();
266  }
267}
268
269void G1MonitoringSupport::update_eden_size() {
270  recalculate_eden_size();
271  if (UsePerfData) {
272    eden_counters()->update_used(eden_space_used());
273  }
274}
275