/* * Copyright (c) 2017, 2018, Red Hat, Inc. 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_EPSILON_GLOBALS_HPP #define SHARE_VM_GC_EPSILON_GLOBALS_HPP #include "runtime/globals.hpp" // // Defines all globals flags used by the Epsilon GC. // #define GC_EPSILON_FLAGS(develop, \ develop_pd, \ product, \ product_pd, \ diagnostic, \ diagnostic_pd, \ experimental, \ notproduct, \ manageable, \ product_rw, \ lp64_product, \ range, \ constraint, \ writeable) \ \ experimental(size_t, EpsilonPrintHeapSteps, 20, \ "Print heap occupancy stats with this number of steps. " \ "0 turns the printing off.") \ range(0, max_intx) \ \ experimental(size_t, EpsilonUpdateCountersStep, 1 * M, \ "Update heap occupancy counters after allocating this much " \ "memory. Higher values would make allocations faster at " \ "the expense of lower resolution in heap counters.") \ range(1, max_intx) \ \ experimental(size_t, EpsilonMaxTLABSize, 4 * M, \ "Max TLAB size to use with Epsilon GC. Larger value improves " \ "performance at the expense of per-thread memory waste. This " \ "asks TLAB machinery to cap TLAB sizes at this value.") \ range(1, max_intx) \ \ experimental(bool, EpsilonElasticTLAB, true, \ "Use elastic policy to manage TLAB sizes. This conserves memory " \ "for non-actively allocating threads, even when they request " \ "large TLABs for themselves. Active threads would experience " \ "smaller TLABs until policy catches up.") \ \ experimental(bool, EpsilonElasticTLABDecay, true, \ "Use timed decays to shrik TLAB sizes. This conserves memory " \ "for the threads that allocate in bursts of different sizes, " \ "for example the small/rare allocations coming after the initial "\ "large burst.") \ \ experimental(double, EpsilonTLABElasticity, 1.1, \ "Multiplier to use when deciding on next TLAB size. Larger value "\ "improves performance at the expense of per-thread memory waste. "\ "Lower value improves memory footprint, but penalizes actively " \ "allocating threads.") \ range(1, max_intx) \ \ experimental(size_t, EpsilonTLABDecayTime, 1000, \ "TLAB sizing policy decays to initial size after thread had not " \ "allocated for this long. Time is in milliseconds. Lower value " \ "improves memory footprint, but penalizes actively allocating " \ "threads.") \ range(1, max_intx) \ \ experimental(size_t, EpsilonMinHeapExpand, 128 * M, \ "Min expansion step for heap. Larger value improves performance " \ "at the potential expense of memory waste.") \ range(1, max_intx) #endif // SHARE_VM_GC_EPSILON_GLOBALS_HPP