duke@435: /* trims@2708: * Copyright (c) 2001, 2011, Oracle and/or its affiliates. All rights reserved. duke@435: * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. duke@435: * duke@435: * This code is free software; you can redistribute it and/or modify it duke@435: * under the terms of the GNU General Public License version 2 only, as duke@435: * published by the Free Software Foundation. duke@435: * duke@435: * This code is distributed in the hope that it will be useful, but WITHOUT duke@435: * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or duke@435: * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License duke@435: * version 2 for more details (a copy is included in the LICENSE file that duke@435: * accompanied this code). duke@435: * duke@435: * You should have received a copy of the GNU General Public License version duke@435: * 2 along with this work; if not, write to the Free Software Foundation, duke@435: * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. duke@435: * trims@1907: * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA trims@1907: * or visit www.oracle.com if you need additional information or have any trims@1907: * questions. duke@435: * duke@435: */ duke@435: stefank@2314: #ifndef SHARE_VM_GC_IMPLEMENTATION_SHARED_ALLOCATIONSTATS_HPP stefank@2314: #define SHARE_VM_GC_IMPLEMENTATION_SHARED_ALLOCATIONSTATS_HPP stefank@2314: stefank@2314: #ifndef SERIALGC stefank@2314: #include "gc_implementation/shared/gcUtil.hpp" stefank@2314: #include "memory/allocation.hpp" stefank@2314: #include "utilities/globalDefinitions.hpp" stefank@2314: #endif stefank@2314: duke@435: class AllocationStats VALUE_OBJ_CLASS_SPEC { duke@435: // A duration threshold (in ms) used to filter duke@435: // possibly unreliable samples. duke@435: static float _threshold; duke@435: duke@435: // We measure the demand between the end of the previous sweep and duke@435: // beginning of this sweep: duke@435: // Count(end_last_sweep) - Count(start_this_sweep) jmasa@3732: // + split_births(between) - split_deaths(between) ysr@1580: // The above number divided by the time since the end of the duke@435: // previous sweep gives us a time rate of demand for blocks duke@435: // of this size. We compute a padded average of this rate as duke@435: // our current estimate for the time rate of demand for blocks duke@435: // of this size. Similarly, we keep a padded average for the time duke@435: // between sweeps. Our current estimate for demand for blocks of duke@435: // this size is then simply computed as the product of these two duke@435: // estimates. duke@435: AdaptivePaddedAverage _demand_rate_estimate; duke@435: ysr@1580: ssize_t _desired; // Demand stimate computed as described above jmasa@3732: ssize_t _coal_desired; // desired +/- small-percent for tuning coalescing duke@435: duke@435: ssize_t _surplus; // count - (desired +/- small-percent), duke@435: // used to tune splitting in best fit jmasa@3732: ssize_t _bfr_surp; // surplus at start of current sweep jmasa@3732: ssize_t _prev_sweep; // count from end of previous sweep jmasa@3732: ssize_t _before_sweep; // count from before current sweep jmasa@3732: ssize_t _coal_births; // additional chunks from coalescing jmasa@3732: ssize_t _coal_deaths; // loss from coalescing jmasa@3732: ssize_t _split_births; // additional chunks from splitting jmasa@3732: ssize_t _split_deaths; // loss from splitting jmasa@3732: size_t _returned_bytes; // number of bytes returned to list. duke@435: public: ysr@1580: void initialize(bool split_birth = false) { duke@435: AdaptivePaddedAverage* dummy = duke@435: new (&_demand_rate_estimate) AdaptivePaddedAverage(CMS_FLSWeight, duke@435: CMS_FLSPadding); duke@435: _desired = 0; jmasa@3732: _coal_desired = 0; duke@435: _surplus = 0; jmasa@3732: _bfr_surp = 0; jmasa@3732: _prev_sweep = 0; jmasa@3732: _before_sweep = 0; jmasa@3732: _coal_births = 0; jmasa@3732: _coal_deaths = 0; jmasa@3732: _split_births = (split_birth ? 1 : 0); jmasa@3732: _split_deaths = 0; jmasa@3732: _returned_bytes = 0; duke@435: } duke@435: duke@435: AllocationStats() { duke@435: initialize(); duke@435: } ysr@1580: duke@435: // The rate estimate is in blocks per second. duke@435: void compute_desired(size_t count, duke@435: float inter_sweep_current, ysr@1580: float inter_sweep_estimate, ysr@1580: float intra_sweep_estimate) { duke@435: // If the latest inter-sweep time is below our granularity duke@435: // of measurement, we may call in here with duke@435: // inter_sweep_current == 0. However, even for suitably small duke@435: // but non-zero inter-sweep durations, we may not trust the accuracy duke@435: // of accumulated data, since it has not been "integrated" duke@435: // (read "low-pass-filtered") long enough, and would be duke@435: // vulnerable to noisy glitches. In such cases, we duke@435: // ignore the current sample and use currently available duke@435: // historical estimates. jmasa@3732: assert(prev_sweep() + split_births() + coal_births() // "Total Production Stock" jmasa@3732: >= split_deaths() + coal_deaths() + (ssize_t)count, // "Current stock + depletion" ysr@2972: "Conservation Principle"); duke@435: if (inter_sweep_current > _threshold) { jmasa@3732: ssize_t demand = prev_sweep() - (ssize_t)count + split_births() + coal_births() jmasa@3732: - split_deaths() - coal_deaths(); ysr@2972: assert(demand >= 0, ysr@2972: err_msg("Demand (" SSIZE_FORMAT ") should be non-negative for " ysr@2972: PTR_FORMAT " (size=" SIZE_FORMAT ")", ysr@2972: demand, this, count)); ysr@1580: // Defensive: adjust for imprecision in event counting ysr@1580: if (demand < 0) { ysr@1580: demand = 0; ysr@1580: } ysr@1580: float old_rate = _demand_rate_estimate.padded_average(); duke@435: float rate = ((float)demand)/inter_sweep_current; duke@435: _demand_rate_estimate.sample(rate); ysr@1580: float new_rate = _demand_rate_estimate.padded_average(); ysr@1580: ssize_t old_desired = _desired; ysr@2502: float delta_ise = (CMSExtrapolateSweep ? intra_sweep_estimate : 0.0); ysr@2502: _desired = (ssize_t)(new_rate * (inter_sweep_estimate + delta_ise)); ysr@1580: if (PrintFLSStatistics > 1) { ysr@1580: gclog_or_tty->print_cr("demand: %d, old_rate: %f, current_rate: %f, new_rate: %f, old_desired: %d, new_desired: %d", ysr@1580: demand, old_rate, rate, new_rate, old_desired, _desired); ysr@1580: } duke@435: } duke@435: } duke@435: duke@435: ssize_t desired() const { return _desired; } ysr@447: void set_desired(ssize_t v) { _desired = v; } ysr@447: jmasa@3732: ssize_t coal_desired() const { return _coal_desired; } jmasa@3732: void set_coal_desired(ssize_t v) { _coal_desired = v; } duke@435: duke@435: ssize_t surplus() const { return _surplus; } duke@435: void set_surplus(ssize_t v) { _surplus = v; } duke@435: void increment_surplus() { _surplus++; } duke@435: void decrement_surplus() { _surplus--; } duke@435: jmasa@3732: ssize_t bfr_surp() const { return _bfr_surp; } jmasa@3732: void set_bfr_surp(ssize_t v) { _bfr_surp = v; } jmasa@3732: ssize_t prev_sweep() const { return _prev_sweep; } jmasa@3732: void set_prev_sweep(ssize_t v) { _prev_sweep = v; } jmasa@3732: ssize_t before_sweep() const { return _before_sweep; } jmasa@3732: void set_before_sweep(ssize_t v) { _before_sweep = v; } duke@435: jmasa@3732: ssize_t coal_births() const { return _coal_births; } jmasa@3732: void set_coal_births(ssize_t v) { _coal_births = v; } jmasa@3732: void increment_coal_births() { _coal_births++; } duke@435: jmasa@3732: ssize_t coal_deaths() const { return _coal_deaths; } jmasa@3732: void set_coal_deaths(ssize_t v) { _coal_deaths = v; } jmasa@3732: void increment_coal_deaths() { _coal_deaths++; } duke@435: jmasa@3732: ssize_t split_births() const { return _split_births; } jmasa@3732: void set_split_births(ssize_t v) { _split_births = v; } jmasa@3732: void increment_split_births() { _split_births++; } duke@435: jmasa@3732: ssize_t split_deaths() const { return _split_deaths; } jmasa@3732: void set_split_deaths(ssize_t v) { _split_deaths = v; } jmasa@3732: void increment_split_deaths() { _split_deaths++; } duke@435: duke@435: NOT_PRODUCT( jmasa@3732: size_t returned_bytes() const { return _returned_bytes; } jmasa@3732: void set_returned_bytes(size_t v) { _returned_bytes = v; } duke@435: ) duke@435: }; stefank@2314: stefank@2314: #endif // SHARE_VM_GC_IMPLEMENTATION_SHARED_ALLOCATIONSTATS_HPP