diff -r e45861098f5a -r fec48bf5a827 hotspot/src/share/vm/gc/parallel/adjoiningGenerations.cpp --- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/hotspot/src/share/vm/gc/parallel/adjoiningGenerations.cpp Wed May 13 15:16:06 2015 +0200 @@ -0,0 +1,284 @@ +/* + * Copyright (c) 2003, 2015, 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. + * + */ + +#include "precompiled.hpp" +#include "gc/parallel/adjoiningGenerations.hpp" +#include "gc/parallel/adjoiningVirtualSpaces.hpp" +#include "gc/parallel/generationSizer.hpp" +#include "gc/parallel/parallelScavengeHeap.hpp" + +// If boundary moving is being used, create the young gen and old +// gen with ASPSYoungGen and ASPSOldGen, respectively. Revert to +// the old behavior otherwise (with PSYoungGen and PSOldGen). + +AdjoiningGenerations::AdjoiningGenerations(ReservedSpace old_young_rs, + GenerationSizer* policy, + size_t alignment) : + _virtual_spaces(old_young_rs, policy->min_old_size(), + policy->min_young_size(), alignment) { + size_t init_low_byte_size = policy->initial_old_size(); + size_t min_low_byte_size = policy->min_old_size(); + size_t max_low_byte_size = policy->max_old_size(); + size_t init_high_byte_size = policy->initial_young_size(); + size_t min_high_byte_size = policy->min_young_size(); + size_t max_high_byte_size = policy->max_young_size(); + + assert(min_low_byte_size <= init_low_byte_size && + init_low_byte_size <= max_low_byte_size, "Parameter check"); + assert(min_high_byte_size <= init_high_byte_size && + init_high_byte_size <= max_high_byte_size, "Parameter check"); + // Create the generations differently based on the option to + // move the boundary. + if (UseAdaptiveGCBoundary) { + // Initialize the adjoining virtual spaces. Then pass the + // a virtual to each generation for initialization of the + // generation. + + // Does the actual creation of the virtual spaces + _virtual_spaces.initialize(max_low_byte_size, + init_low_byte_size, + init_high_byte_size); + + // Place the young gen at the high end. Passes in the virtual space. + _young_gen = new ASPSYoungGen(_virtual_spaces.high(), + _virtual_spaces.high()->committed_size(), + min_high_byte_size, + _virtual_spaces.high_byte_size_limit()); + + // Place the old gen at the low end. Passes in the virtual space. + _old_gen = new ASPSOldGen(_virtual_spaces.low(), + _virtual_spaces.low()->committed_size(), + min_low_byte_size, + _virtual_spaces.low_byte_size_limit(), + "old", 1); + + young_gen()->initialize_work(); + assert(young_gen()->reserved().byte_size() <= young_gen()->gen_size_limit(), + "Consistency check"); + assert(old_young_rs.size() >= young_gen()->gen_size_limit(), + "Consistency check"); + + old_gen()->initialize_work("old", 1); + assert(old_gen()->reserved().byte_size() <= old_gen()->gen_size_limit(), + "Consistency check"); + assert(old_young_rs.size() >= old_gen()->gen_size_limit(), + "Consistency check"); + } else { + + // Layout the reserved space for the generations. + ReservedSpace old_rs = + virtual_spaces()->reserved_space().first_part(max_low_byte_size); + ReservedSpace heap_rs = + virtual_spaces()->reserved_space().last_part(max_low_byte_size); + ReservedSpace young_rs = heap_rs.first_part(max_high_byte_size); + assert(young_rs.size() == heap_rs.size(), "Didn't reserve all of the heap"); + + // Create the generations. Virtual spaces are not passed in. + _young_gen = new PSYoungGen(init_high_byte_size, + min_high_byte_size, + max_high_byte_size); + _old_gen = new PSOldGen(init_low_byte_size, + min_low_byte_size, + max_low_byte_size, + "old", 1); + + // The virtual spaces are created by the initialization of the gens. + _young_gen->initialize(young_rs, alignment); + assert(young_gen()->gen_size_limit() == young_rs.size(), + "Consistency check"); + _old_gen->initialize(old_rs, alignment, "old", 1); + assert(old_gen()->gen_size_limit() == old_rs.size(), "Consistency check"); + } +} + +size_t AdjoiningGenerations::reserved_byte_size() { + return virtual_spaces()->reserved_space().size(); +} + + +// Make checks on the current sizes of the generations and +// the constraints on the sizes of the generations. Push +// up the boundary within the constraints. A partial +// push can occur. +void AdjoiningGenerations::request_old_gen_expansion(size_t expand_in_bytes) { + assert(UseAdaptiveSizePolicy && UseAdaptiveGCBoundary, "runtime check"); + + assert_lock_strong(ExpandHeap_lock); + assert_locked_or_safepoint(Heap_lock); + + // These sizes limit the amount the boundaries can move. Effectively, + // the generation says how much it is willing to yield to the other + // generation. + const size_t young_gen_available = young_gen()->available_for_contraction(); + const size_t old_gen_available = old_gen()->available_for_expansion(); + const size_t alignment = virtual_spaces()->alignment(); + size_t change_in_bytes = MIN3(young_gen_available, + old_gen_available, + align_size_up_(expand_in_bytes, alignment)); + + if (change_in_bytes == 0) { + return; + } + + if (TraceAdaptiveGCBoundary) { + gclog_or_tty->print_cr("Before expansion of old gen with boundary move"); + gclog_or_tty->print_cr(" Requested change: " SIZE_FORMAT_HEX + " Attempted change: " SIZE_FORMAT_HEX, + expand_in_bytes, change_in_bytes); + if (!PrintHeapAtGC) { + Universe::print_on(gclog_or_tty); + } + gclog_or_tty->print_cr(" PSOldGen max size: " SIZE_FORMAT "K", + old_gen()->max_gen_size()/K); + } + + // Move the boundary between the generations up (smaller young gen). + if (virtual_spaces()->adjust_boundary_up(change_in_bytes)) { + young_gen()->reset_after_change(); + old_gen()->reset_after_change(); + } + + // The total reserved for the generations should match the sum + // of the two even if the boundary is moving. + assert(reserved_byte_size() == + old_gen()->max_gen_size() + young_gen()->max_size(), + "Space is missing"); + young_gen()->space_invariants(); + old_gen()->space_invariants(); + + if (TraceAdaptiveGCBoundary) { + gclog_or_tty->print_cr("After expansion of old gen with boundary move"); + if (!PrintHeapAtGC) { + Universe::print_on(gclog_or_tty); + } + gclog_or_tty->print_cr(" PSOldGen max size: " SIZE_FORMAT "K", + old_gen()->max_gen_size()/K); + } +} + +// See comments on request_old_gen_expansion() +bool AdjoiningGenerations::request_young_gen_expansion(size_t expand_in_bytes) { + assert(UseAdaptiveSizePolicy && UseAdaptiveGCBoundary, "runtime check"); + + // If eden is not empty, the boundary can be moved but no advantage + // can be made of the move since eden cannot be moved. + if (!young_gen()->eden_space()->is_empty()) { + return false; + } + + + bool result = false; + const size_t young_gen_available = young_gen()->available_for_expansion(); + const size_t old_gen_available = old_gen()->available_for_contraction(); + const size_t alignment = virtual_spaces()->alignment(); + size_t change_in_bytes = MIN3(young_gen_available, + old_gen_available, + align_size_up_(expand_in_bytes, alignment)); + + if (change_in_bytes == 0) { + return false; + } + + if (TraceAdaptiveGCBoundary) { + gclog_or_tty->print_cr("Before expansion of young gen with boundary move"); + gclog_or_tty->print_cr(" Requested change: " SIZE_FORMAT_HEX " Attempted change: " SIZE_FORMAT_HEX, + expand_in_bytes, change_in_bytes); + if (!PrintHeapAtGC) { + Universe::print_on(gclog_or_tty); + } + gclog_or_tty->print_cr(" PSYoungGen max size: " SIZE_FORMAT "K", + young_gen()->max_size()/K); + } + + // Move the boundary between the generations down (smaller old gen). + MutexLocker x(ExpandHeap_lock); + if (virtual_spaces()->adjust_boundary_down(change_in_bytes)) { + young_gen()->reset_after_change(); + old_gen()->reset_after_change(); + result = true; + } + + // The total reserved for the generations should match the sum + // of the two even if the boundary is moving. + assert(reserved_byte_size() == + old_gen()->max_gen_size() + young_gen()->max_size(), + "Space is missing"); + young_gen()->space_invariants(); + old_gen()->space_invariants(); + + if (TraceAdaptiveGCBoundary) { + gclog_or_tty->print_cr("After expansion of young gen with boundary move"); + if (!PrintHeapAtGC) { + Universe::print_on(gclog_or_tty); + } + gclog_or_tty->print_cr(" PSYoungGen max size: " SIZE_FORMAT "K", + young_gen()->max_size()/K); + } + + return result; +} + +// Additional space is needed in the old generation. Try to move the boundary +// up to meet the need. Moves boundary up only +void AdjoiningGenerations::adjust_boundary_for_old_gen_needs( + size_t desired_free_space) { + assert(UseAdaptiveSizePolicy && UseAdaptiveGCBoundary, "runtime check"); + + // Stress testing. + if (PSAdaptiveSizePolicyResizeVirtualSpaceAlot == 1) { + MutexLocker x(ExpandHeap_lock); + request_old_gen_expansion(virtual_spaces()->alignment() * 3 / 2); + } + + // Expand only if the entire generation is already committed. + if (old_gen()->virtual_space()->uncommitted_size() == 0) { + if (old_gen()->free_in_bytes() < desired_free_space) { + MutexLocker x(ExpandHeap_lock); + request_old_gen_expansion(desired_free_space); + } + } +} + +// See comment on adjust_boundary_for_old_gen_needss(). +// Adjust boundary down only. +void AdjoiningGenerations::adjust_boundary_for_young_gen_needs(size_t eden_size, + size_t survivor_size) { + + assert(UseAdaptiveSizePolicy && UseAdaptiveGCBoundary, "runtime check"); + + // Stress testing. + if (PSAdaptiveSizePolicyResizeVirtualSpaceAlot == 0) { + request_young_gen_expansion(virtual_spaces()->alignment() * 3 / 2); + eden_size = young_gen()->eden_space()->capacity_in_bytes(); + } + + // Expand only if the entire generation is already committed. + if (young_gen()->virtual_space()->uncommitted_size() == 0) { + size_t desired_size = eden_size + 2 * survivor_size; + const size_t committed = young_gen()->virtual_space()->committed_size(); + if (desired_size > committed) { + request_young_gen_expansion(desired_size - committed); + } + } +}