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src/share/vm/gc_implementation/shared/allocationStats.hpp@710a3c8b516e (annotated)
src/share/vm/gc_implementation/shared/allocationStats.hpp
Tue, 08 Aug 2017 15:57:29 +0800
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- aoqi
- date
- Tue, 08 Aug 2017 15:57:29 +0800
- changeset 6876
- 710a3c8b516e
- parent 6680
- 78bbf4d43a14
- parent 0
- f90c822e73f8
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| aoqi@0 | 1 | /* |
| aoqi@0 | 2 | * Copyright (c) 2001, 2014, Oracle and/or its affiliates. All rights reserved. |
| aoqi@0 | 3 | * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
| aoqi@0 | 4 | * |
| aoqi@0 | 5 | * This code is free software; you can redistribute it and/or modify it |
| aoqi@0 | 6 | * under the terms of the GNU General Public License version 2 only, as |
| aoqi@0 | 7 | * published by the Free Software Foundation. |
| aoqi@0 | 8 | * |
| aoqi@0 | 9 | * This code is distributed in the hope that it will be useful, but WITHOUT |
| aoqi@0 | 10 | * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
| aoqi@0 | 11 | * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
| aoqi@0 | 12 | * version 2 for more details (a copy is included in the LICENSE file that |
| aoqi@0 | 13 | * accompanied this code). |
| aoqi@0 | 14 | * |
| aoqi@0 | 15 | * You should have received a copy of the GNU General Public License version |
| aoqi@0 | 16 | * 2 along with this work; if not, write to the Free Software Foundation, |
| aoqi@0 | 17 | * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. |
| aoqi@0 | 18 | * |
| aoqi@0 | 19 | * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA |
| aoqi@0 | 20 | * or visit www.oracle.com if you need additional information or have any |
| aoqi@0 | 21 | * questions. |
| aoqi@0 | 22 | * |
| aoqi@0 | 23 | */ |
| aoqi@0 | 24 | |
| aoqi@0 | 25 | #ifndef SHARE_VM_GC_IMPLEMENTATION_SHARED_ALLOCATIONSTATS_HPP |
| aoqi@0 | 26 | #define SHARE_VM_GC_IMPLEMENTATION_SHARED_ALLOCATIONSTATS_HPP |
| aoqi@0 | 27 | |
| aoqi@0 | 28 | #include "utilities/macros.hpp" |
| aoqi@0 | 29 | #include "memory/allocation.hpp" |
| aoqi@0 | 30 | #include "utilities/globalDefinitions.hpp" |
| aoqi@0 | 31 | #include "gc_implementation/shared/gcUtil.hpp" |
| aoqi@0 | 32 | |
| aoqi@0 | 33 | class AllocationStats VALUE_OBJ_CLASS_SPEC { |
| aoqi@0 | 34 | // A duration threshold (in ms) used to filter |
| aoqi@0 | 35 | // possibly unreliable samples. |
| aoqi@0 | 36 | static float _threshold; |
| aoqi@0 | 37 | |
| aoqi@0 | 38 | // We measure the demand between the end of the previous sweep and |
| aoqi@0 | 39 | // beginning of this sweep: |
| aoqi@0 | 40 | // Count(end_last_sweep) - Count(start_this_sweep) |
| aoqi@0 | 41 | // + split_births(between) - split_deaths(between) |
| aoqi@0 | 42 | // The above number divided by the time since the end of the |
| aoqi@0 | 43 | // previous sweep gives us a time rate of demand for blocks |
| aoqi@0 | 44 | // of this size. We compute a padded average of this rate as |
| aoqi@0 | 45 | // our current estimate for the time rate of demand for blocks |
| aoqi@0 | 46 | // of this size. Similarly, we keep a padded average for the time |
| aoqi@0 | 47 | // between sweeps. Our current estimate for demand for blocks of |
| aoqi@0 | 48 | // this size is then simply computed as the product of these two |
| aoqi@0 | 49 | // estimates. |
| aoqi@0 | 50 | AdaptivePaddedAverage _demand_rate_estimate; |
| aoqi@0 | 51 | |
| aoqi@0 | 52 | ssize_t _desired; // Demand stimate computed as described above |
| aoqi@0 | 53 | ssize_t _coal_desired; // desired +/- small-percent for tuning coalescing |
| aoqi@0 | 54 | |
| aoqi@0 | 55 | ssize_t _surplus; // count - (desired +/- small-percent), |
| aoqi@0 | 56 | // used to tune splitting in best fit |
| aoqi@0 | 57 | ssize_t _bfr_surp; // surplus at start of current sweep |
| aoqi@0 | 58 | ssize_t _prev_sweep; // count from end of previous sweep |
| aoqi@0 | 59 | ssize_t _before_sweep; // count from before current sweep |
| aoqi@0 | 60 | ssize_t _coal_births; // additional chunks from coalescing |
| aoqi@0 | 61 | ssize_t _coal_deaths; // loss from coalescing |
| aoqi@0 | 62 | ssize_t _split_births; // additional chunks from splitting |
| aoqi@0 | 63 | ssize_t _split_deaths; // loss from splitting |
| aoqi@0 | 64 | size_t _returned_bytes; // number of bytes returned to list. |
| aoqi@0 | 65 | public: |
| aoqi@0 | 66 | void initialize(bool split_birth = false) { |
| aoqi@0 | 67 | AdaptivePaddedAverage* dummy = |
| aoqi@0 | 68 | new (&_demand_rate_estimate) AdaptivePaddedAverage(CMS_FLSWeight, |
| aoqi@0 | 69 | CMS_FLSPadding); |
| aoqi@0 | 70 | _desired = 0; |
| aoqi@0 | 71 | _coal_desired = 0; |
| aoqi@0 | 72 | _surplus = 0; |
| aoqi@0 | 73 | _bfr_surp = 0; |
| aoqi@0 | 74 | _prev_sweep = 0; |
| aoqi@0 | 75 | _before_sweep = 0; |
| aoqi@0 | 76 | _coal_births = 0; |
| aoqi@0 | 77 | _coal_deaths = 0; |
| aoqi@0 | 78 | _split_births = (split_birth ? 1 : 0); |
| aoqi@0 | 79 | _split_deaths = 0; |
| aoqi@0 | 80 | _returned_bytes = 0; |
| aoqi@0 | 81 | } |
| aoqi@0 | 82 | |
| aoqi@0 | 83 | AllocationStats() { |
| aoqi@0 | 84 | initialize(); |
| aoqi@0 | 85 | } |
| aoqi@0 | 86 | |
| aoqi@0 | 87 | // The rate estimate is in blocks per second. |
| aoqi@0 | 88 | void compute_desired(size_t count, |
| aoqi@0 | 89 | float inter_sweep_current, |
| aoqi@0 | 90 | float inter_sweep_estimate, |
| aoqi@0 | 91 | float intra_sweep_estimate) { |
| aoqi@0 | 92 | // If the latest inter-sweep time is below our granularity |
| aoqi@0 | 93 | // of measurement, we may call in here with |
| aoqi@0 | 94 | // inter_sweep_current == 0. However, even for suitably small |
| aoqi@0 | 95 | // but non-zero inter-sweep durations, we may not trust the accuracy |
| aoqi@0 | 96 | // of accumulated data, since it has not been "integrated" |
| aoqi@0 | 97 | // (read "low-pass-filtered") long enough, and would be |
| aoqi@0 | 98 | // vulnerable to noisy glitches. In such cases, we |
| aoqi@0 | 99 | // ignore the current sample and use currently available |
| aoqi@0 | 100 | // historical estimates. |
| aoqi@0 | 101 | assert(prev_sweep() + split_births() + coal_births() // "Total Production Stock" |
| aoqi@0 | 102 | >= split_deaths() + coal_deaths() + (ssize_t)count, // "Current stock + depletion" |
| aoqi@0 | 103 | "Conservation Principle"); |
| aoqi@0 | 104 | if (inter_sweep_current > _threshold) { |
| aoqi@0 | 105 | ssize_t demand = prev_sweep() - (ssize_t)count + split_births() + coal_births() |
| aoqi@0 | 106 | - split_deaths() - coal_deaths(); |
| aoqi@0 | 107 | assert(demand >= 0, |
| aoqi@0 | 108 | err_msg("Demand (" SSIZE_FORMAT ") should be non-negative for " |
| aoqi@0 | 109 | PTR_FORMAT " (size=" SIZE_FORMAT ")", |
| aoqi@0 | 110 | demand, p2i(this), count)); |
| aoqi@0 | 111 | // Defensive: adjust for imprecision in event counting |
| aoqi@0 | 112 | if (demand < 0) { |
| aoqi@0 | 113 | demand = 0; |
| aoqi@0 | 114 | } |
| aoqi@0 | 115 | float old_rate = _demand_rate_estimate.padded_average(); |
| aoqi@0 | 116 | float rate = ((float)demand)/inter_sweep_current; |
| aoqi@0 | 117 | _demand_rate_estimate.sample(rate); |
| aoqi@0 | 118 | float new_rate = _demand_rate_estimate.padded_average(); |
| aoqi@0 | 119 | ssize_t old_desired = _desired; |
| aoqi@0 | 120 | float delta_ise = (CMSExtrapolateSweep ? intra_sweep_estimate : 0.0); |
| aoqi@0 | 121 | _desired = (ssize_t)(new_rate * (inter_sweep_estimate + delta_ise)); |
| aoqi@0 | 122 | if (PrintFLSStatistics > 1) { |
| aoqi@0 | 123 | gclog_or_tty->print_cr( |
| aoqi@0 | 124 | "demand: " SSIZE_FORMAT ", old_rate: %f, current_rate: %f, new_rate: %f, old_desired: " SSIZE_FORMAT ", new_desired: " SSIZE_FORMAT, |
| aoqi@0 | 125 | demand, old_rate, rate, new_rate, old_desired, _desired); |
| aoqi@0 | 126 | } |
| aoqi@0 | 127 | } |
| aoqi@0 | 128 | } |
| aoqi@0 | 129 | |
| aoqi@0 | 130 | ssize_t desired() const { return _desired; } |
| aoqi@0 | 131 | void set_desired(ssize_t v) { _desired = v; } |
| aoqi@0 | 132 | |
| aoqi@0 | 133 | ssize_t coal_desired() const { return _coal_desired; } |
| aoqi@0 | 134 | void set_coal_desired(ssize_t v) { _coal_desired = v; } |
| aoqi@0 | 135 | |
| aoqi@0 | 136 | ssize_t surplus() const { return _surplus; } |
| aoqi@0 | 137 | void set_surplus(ssize_t v) { _surplus = v; } |
| aoqi@0 | 138 | void increment_surplus() { _surplus++; } |
| aoqi@0 | 139 | void decrement_surplus() { _surplus--; } |
| aoqi@0 | 140 | |
| aoqi@0 | 141 | ssize_t bfr_surp() const { return _bfr_surp; } |
| aoqi@0 | 142 | void set_bfr_surp(ssize_t v) { _bfr_surp = v; } |
| aoqi@0 | 143 | ssize_t prev_sweep() const { return _prev_sweep; } |
| aoqi@0 | 144 | void set_prev_sweep(ssize_t v) { _prev_sweep = v; } |
| aoqi@0 | 145 | ssize_t before_sweep() const { return _before_sweep; } |
| aoqi@0 | 146 | void set_before_sweep(ssize_t v) { _before_sweep = v; } |
| aoqi@0 | 147 | |
| aoqi@0 | 148 | ssize_t coal_births() const { return _coal_births; } |
| aoqi@0 | 149 | void set_coal_births(ssize_t v) { _coal_births = v; } |
| aoqi@0 | 150 | void increment_coal_births() { _coal_births++; } |
| aoqi@0 | 151 | |
| aoqi@0 | 152 | ssize_t coal_deaths() const { return _coal_deaths; } |
| aoqi@0 | 153 | void set_coal_deaths(ssize_t v) { _coal_deaths = v; } |
| aoqi@0 | 154 | void increment_coal_deaths() { _coal_deaths++; } |
| aoqi@0 | 155 | |
| aoqi@0 | 156 | ssize_t split_births() const { return _split_births; } |
| aoqi@0 | 157 | void set_split_births(ssize_t v) { _split_births = v; } |
| aoqi@0 | 158 | void increment_split_births() { _split_births++; } |
| aoqi@0 | 159 | |
| aoqi@0 | 160 | ssize_t split_deaths() const { return _split_deaths; } |
| aoqi@0 | 161 | void set_split_deaths(ssize_t v) { _split_deaths = v; } |
| aoqi@0 | 162 | void increment_split_deaths() { _split_deaths++; } |
| aoqi@0 | 163 | |
| aoqi@0 | 164 | NOT_PRODUCT( |
| aoqi@0 | 165 | size_t returned_bytes() const { return _returned_bytes; } |
| aoqi@0 | 166 | void set_returned_bytes(size_t v) { _returned_bytes = v; } |
| aoqi@0 | 167 | ) |
| aoqi@0 | 168 | }; |
| aoqi@0 | 169 | |
| aoqi@0 | 170 | #endif // SHARE_VM_GC_IMPLEMENTATION_SHARED_ALLOCATIONSTATS_HPP |
