Mercurial > hg > graal-jvmci-8
annotate src/share/vm/gc_implementation/shared/allocationStats.hpp @ 941:8b46c4d82093
4957990: Perm heap bloat in JVM
Summary: Treat ProfileData in MDO's as a source of weak, not strong, roots. Fixes the bug for stop-world collection -- the case of concurrent collection will be fixed separately.
Reviewed-by: jcoomes, jmasa, kvn, never
author | ysr |
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date | Wed, 02 Sep 2009 00:04:29 -0700 |
parents | d1605aabd0a1 |
children | e018e6884bd8 |
rev | line source |
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0 | 1 /* |
196 | 2 * Copyright 2001-2008 Sun Microsystems, Inc. All Rights Reserved. |
0 | 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 class AllocationStats VALUE_OBJ_CLASS_SPEC { | |
26 // A duration threshold (in ms) used to filter | |
27 // possibly unreliable samples. | |
28 static float _threshold; | |
29 | |
30 // We measure the demand between the end of the previous sweep and | |
31 // beginning of this sweep: | |
32 // Count(end_last_sweep) - Count(start_this_sweep) | |
33 // + splitBirths(between) - splitDeaths(between) | |
34 // The above number divided by the time since the start [END???] of the | |
35 // previous sweep gives us a time rate of demand for blocks | |
36 // of this size. We compute a padded average of this rate as | |
37 // our current estimate for the time rate of demand for blocks | |
38 // of this size. Similarly, we keep a padded average for the time | |
39 // between sweeps. Our current estimate for demand for blocks of | |
40 // this size is then simply computed as the product of these two | |
41 // estimates. | |
42 AdaptivePaddedAverage _demand_rate_estimate; | |
43 | |
44 ssize_t _desired; // Estimate computed as described above | |
45 ssize_t _coalDesired; // desired +/- small-percent for tuning coalescing | |
46 | |
47 ssize_t _surplus; // count - (desired +/- small-percent), | |
48 // used to tune splitting in best fit | |
49 ssize_t _bfrSurp; // surplus at start of current sweep | |
50 ssize_t _prevSweep; // count from end of previous sweep | |
51 ssize_t _beforeSweep; // count from before current sweep | |
52 ssize_t _coalBirths; // additional chunks from coalescing | |
53 ssize_t _coalDeaths; // loss from coalescing | |
54 ssize_t _splitBirths; // additional chunks from splitting | |
55 ssize_t _splitDeaths; // loss from splitting | |
56 size_t _returnedBytes; // number of bytes returned to list. | |
57 public: | |
58 void initialize() { | |
59 AdaptivePaddedAverage* dummy = | |
60 new (&_demand_rate_estimate) AdaptivePaddedAverage(CMS_FLSWeight, | |
61 CMS_FLSPadding); | |
62 _desired = 0; | |
63 _coalDesired = 0; | |
64 _surplus = 0; | |
65 _bfrSurp = 0; | |
66 _prevSweep = 0; | |
67 _beforeSweep = 0; | |
68 _coalBirths = 0; | |
69 _coalDeaths = 0; | |
70 _splitBirths = 0; | |
71 _splitDeaths = 0; | |
72 _returnedBytes = 0; | |
73 } | |
74 | |
75 AllocationStats() { | |
76 initialize(); | |
77 } | |
78 // The rate estimate is in blocks per second. | |
79 void compute_desired(size_t count, | |
80 float inter_sweep_current, | |
81 float inter_sweep_estimate) { | |
82 // If the latest inter-sweep time is below our granularity | |
83 // of measurement, we may call in here with | |
84 // inter_sweep_current == 0. However, even for suitably small | |
85 // but non-zero inter-sweep durations, we may not trust the accuracy | |
86 // of accumulated data, since it has not been "integrated" | |
87 // (read "low-pass-filtered") long enough, and would be | |
88 // vulnerable to noisy glitches. In such cases, we | |
89 // ignore the current sample and use currently available | |
90 // historical estimates. | |
91 if (inter_sweep_current > _threshold) { | |
92 ssize_t demand = prevSweep() - count + splitBirths() - splitDeaths(); | |
93 float rate = ((float)demand)/inter_sweep_current; | |
94 _demand_rate_estimate.sample(rate); | |
95 _desired = (ssize_t)(_demand_rate_estimate.padded_average() | |
96 *inter_sweep_estimate); | |
97 } | |
98 } | |
99 | |
100 ssize_t desired() const { return _desired; } | |
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6432c3bb6240
6668743: CMS: Consolidate block statistics reporting code
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101 void set_desired(ssize_t v) { _desired = v; } |
6432c3bb6240
6668743: CMS: Consolidate block statistics reporting code
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102 |
0 | 103 ssize_t coalDesired() const { return _coalDesired; } |
104 void set_coalDesired(ssize_t v) { _coalDesired = v; } | |
105 | |
106 ssize_t surplus() const { return _surplus; } | |
107 void set_surplus(ssize_t v) { _surplus = v; } | |
108 void increment_surplus() { _surplus++; } | |
109 void decrement_surplus() { _surplus--; } | |
110 | |
111 ssize_t bfrSurp() const { return _bfrSurp; } | |
112 void set_bfrSurp(ssize_t v) { _bfrSurp = v; } | |
113 ssize_t prevSweep() const { return _prevSweep; } | |
114 void set_prevSweep(ssize_t v) { _prevSweep = v; } | |
115 ssize_t beforeSweep() const { return _beforeSweep; } | |
116 void set_beforeSweep(ssize_t v) { _beforeSweep = v; } | |
117 | |
118 ssize_t coalBirths() const { return _coalBirths; } | |
119 void set_coalBirths(ssize_t v) { _coalBirths = v; } | |
120 void increment_coalBirths() { _coalBirths++; } | |
121 | |
122 ssize_t coalDeaths() const { return _coalDeaths; } | |
123 void set_coalDeaths(ssize_t v) { _coalDeaths = v; } | |
124 void increment_coalDeaths() { _coalDeaths++; } | |
125 | |
126 ssize_t splitBirths() const { return _splitBirths; } | |
127 void set_splitBirths(ssize_t v) { _splitBirths = v; } | |
128 void increment_splitBirths() { _splitBirths++; } | |
129 | |
130 ssize_t splitDeaths() const { return _splitDeaths; } | |
131 void set_splitDeaths(ssize_t v) { _splitDeaths = v; } | |
132 void increment_splitDeaths() { _splitDeaths++; } | |
133 | |
134 NOT_PRODUCT( | |
135 size_t returnedBytes() const { return _returnedBytes; } | |
136 void set_returnedBytes(size_t v) { _returnedBytes = v; } | |
137 ) | |
138 }; |