Mercurial > hg > graal-jvmci-8
view src/share/vm/gc_implementation/shared/allocationStats.hpp @ 3285:49a67202bc67
7011855: G1: non-product flag to artificially grow the heap
Summary: It introduces non-product cmd line parameter G1DummyRegionsPerGC which indicates how many "dummy" regions to allocate at the end of each GC. This allows the G1 heap to grow artificially and makes concurrent marking cycles more frequent irrespective of what the application that is running is doing. The dummy regions will be found totally empty during cleanup so this parameter can also be used to stress the concurrent cleanup operation.
Reviewed-by: brutisso, johnc
author | tonyp |
---|---|
date | Tue, 19 Apr 2011 15:46:59 -0400 |
parents | c69b1043dfb1 |
children | f75137faa7fe |
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/* * Copyright (c) 2001, 2011, Oracle and/or its affiliates. All rights reserved. * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. * * This code is free software; you can redistribute it and/or modify it * under the terms of the GNU General Public License version 2 only, as * published by the Free Software Foundation. * * This code is distributed in the hope that it will be useful, but WITHOUT * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License * version 2 for more details (a copy is included in the LICENSE file that * accompanied this code). * * You should have received a copy of the GNU General Public License version * 2 along with this work; if not, write to the Free Software Foundation, * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. * * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA * or visit www.oracle.com if you need additional information or have any * questions. * */ #ifndef SHARE_VM_GC_IMPLEMENTATION_SHARED_ALLOCATIONSTATS_HPP #define SHARE_VM_GC_IMPLEMENTATION_SHARED_ALLOCATIONSTATS_HPP #ifndef SERIALGC #include "gc_implementation/shared/gcUtil.hpp" #include "memory/allocation.hpp" #include "utilities/globalDefinitions.hpp" #endif class AllocationStats VALUE_OBJ_CLASS_SPEC { // A duration threshold (in ms) used to filter // possibly unreliable samples. static float _threshold; // We measure the demand between the end of the previous sweep and // beginning of this sweep: // Count(end_last_sweep) - Count(start_this_sweep) // + splitBirths(between) - splitDeaths(between) // The above number divided by the time since the end of the // previous sweep gives us a time rate of demand for blocks // of this size. We compute a padded average of this rate as // our current estimate for the time rate of demand for blocks // of this size. Similarly, we keep a padded average for the time // between sweeps. Our current estimate for demand for blocks of // this size is then simply computed as the product of these two // estimates. AdaptivePaddedAverage _demand_rate_estimate; ssize_t _desired; // Demand stimate computed as described above ssize_t _coalDesired; // desired +/- small-percent for tuning coalescing ssize_t _surplus; // count - (desired +/- small-percent), // used to tune splitting in best fit ssize_t _bfrSurp; // surplus at start of current sweep ssize_t _prevSweep; // count from end of previous sweep ssize_t _beforeSweep; // count from before current sweep ssize_t _coalBirths; // additional chunks from coalescing ssize_t _coalDeaths; // loss from coalescing ssize_t _splitBirths; // additional chunks from splitting ssize_t _splitDeaths; // loss from splitting size_t _returnedBytes; // number of bytes returned to list. public: void initialize(bool split_birth = false) { AdaptivePaddedAverage* dummy = new (&_demand_rate_estimate) AdaptivePaddedAverage(CMS_FLSWeight, CMS_FLSPadding); _desired = 0; _coalDesired = 0; _surplus = 0; _bfrSurp = 0; _prevSweep = 0; _beforeSweep = 0; _coalBirths = 0; _coalDeaths = 0; _splitBirths = (split_birth ? 1 : 0); _splitDeaths = 0; _returnedBytes = 0; } AllocationStats() { initialize(); } // The rate estimate is in blocks per second. void compute_desired(size_t count, float inter_sweep_current, float inter_sweep_estimate, float intra_sweep_estimate) { // If the latest inter-sweep time is below our granularity // of measurement, we may call in here with // inter_sweep_current == 0. However, even for suitably small // but non-zero inter-sweep durations, we may not trust the accuracy // of accumulated data, since it has not been "integrated" // (read "low-pass-filtered") long enough, and would be // vulnerable to noisy glitches. In such cases, we // ignore the current sample and use currently available // historical estimates. // XXX NEEDS TO BE FIXED // assert(prevSweep() + splitBirths() >= splitDeaths() + (ssize_t)count, "Conservation Principle"); // ^^^^^^^^^^^^^^^^^^^^^^^^^^^ ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ // "Total Stock" "Not used at this block size" if (inter_sweep_current > _threshold) { ssize_t demand = prevSweep() - (ssize_t)count + splitBirths() - splitDeaths(); // XXX NEEDS TO BE FIXED // assert(demand >= 0, "Demand should be non-negative"); // Defensive: adjust for imprecision in event counting if (demand < 0) { demand = 0; } float old_rate = _demand_rate_estimate.padded_average(); float rate = ((float)demand)/inter_sweep_current; _demand_rate_estimate.sample(rate); float new_rate = _demand_rate_estimate.padded_average(); ssize_t old_desired = _desired; float delta_ise = (CMSExtrapolateSweep ? intra_sweep_estimate : 0.0); _desired = (ssize_t)(new_rate * (inter_sweep_estimate + delta_ise)); if (PrintFLSStatistics > 1) { gclog_or_tty->print_cr("demand: %d, old_rate: %f, current_rate: %f, new_rate: %f, old_desired: %d, new_desired: %d", demand, old_rate, rate, new_rate, old_desired, _desired); } } } ssize_t desired() const { return _desired; } void set_desired(ssize_t v) { _desired = v; } ssize_t coalDesired() const { return _coalDesired; } void set_coalDesired(ssize_t v) { _coalDesired = v; } ssize_t surplus() const { return _surplus; } void set_surplus(ssize_t v) { _surplus = v; } void increment_surplus() { _surplus++; } void decrement_surplus() { _surplus--; } ssize_t bfrSurp() const { return _bfrSurp; } void set_bfrSurp(ssize_t v) { _bfrSurp = v; } ssize_t prevSweep() const { return _prevSweep; } void set_prevSweep(ssize_t v) { _prevSweep = v; } ssize_t beforeSweep() const { return _beforeSweep; } void set_beforeSweep(ssize_t v) { _beforeSweep = v; } ssize_t coalBirths() const { return _coalBirths; } void set_coalBirths(ssize_t v) { _coalBirths = v; } void increment_coalBirths() { _coalBirths++; } ssize_t coalDeaths() const { return _coalDeaths; } void set_coalDeaths(ssize_t v) { _coalDeaths = v; } void increment_coalDeaths() { _coalDeaths++; } ssize_t splitBirths() const { return _splitBirths; } void set_splitBirths(ssize_t v) { _splitBirths = v; } void increment_splitBirths() { _splitBirths++; } ssize_t splitDeaths() const { return _splitDeaths; } void set_splitDeaths(ssize_t v) { _splitDeaths = v; } void increment_splitDeaths() { _splitDeaths++; } NOT_PRODUCT( size_t returnedBytes() const { return _returnedBytes; } void set_returnedBytes(size_t v) { _returnedBytes = v; } ) }; #endif // SHARE_VM_GC_IMPLEMENTATION_SHARED_ALLOCATIONSTATS_HPP