| /* |
| * Copyright (c) 2003, 2014, 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_implementation/parallelScavenge/asPSYoungGen.hpp" |
| #include "gc_implementation/parallelScavenge/parallelScavengeHeap.hpp" |
| #include "gc_implementation/parallelScavenge/psMarkSweepDecorator.hpp" |
| #include "gc_implementation/parallelScavenge/psScavenge.hpp" |
| #include "gc_implementation/parallelScavenge/psYoungGen.hpp" |
| #include "gc_implementation/shared/gcUtil.hpp" |
| #include "gc_implementation/shared/spaceDecorator.hpp" |
| #include "oops/oop.inline.hpp" |
| #include "runtime/java.hpp" |
| |
| ASPSYoungGen::ASPSYoungGen(size_t init_byte_size, |
| size_t minimum_byte_size, |
| size_t byte_size_limit) : |
| PSYoungGen(init_byte_size, minimum_byte_size, byte_size_limit), |
| _gen_size_limit(byte_size_limit) { |
| } |
| |
| |
| ASPSYoungGen::ASPSYoungGen(PSVirtualSpace* vs, |
| size_t init_byte_size, |
| size_t minimum_byte_size, |
| size_t byte_size_limit) : |
| //PSYoungGen(init_byte_size, minimum_byte_size, byte_size_limit), |
| PSYoungGen(vs->committed_size(), minimum_byte_size, byte_size_limit), |
| _gen_size_limit(byte_size_limit) { |
| |
| assert(vs->committed_size() == init_byte_size, "Cannot replace with"); |
| |
| _virtual_space = vs; |
| } |
| |
| void ASPSYoungGen::initialize_virtual_space(ReservedSpace rs, |
| size_t alignment) { |
| assert(_init_gen_size != 0, "Should have a finite size"); |
| _virtual_space = new PSVirtualSpaceHighToLow(rs, alignment); |
| if (!_virtual_space->expand_by(_init_gen_size)) { |
| vm_exit_during_initialization("Could not reserve enough space for " |
| "object heap"); |
| } |
| } |
| |
| void ASPSYoungGen::initialize(ReservedSpace rs, size_t alignment) { |
| initialize_virtual_space(rs, alignment); |
| initialize_work(); |
| } |
| |
| size_t ASPSYoungGen::available_for_expansion() { |
| size_t current_committed_size = virtual_space()->committed_size(); |
| assert((gen_size_limit() >= current_committed_size), |
| "generation size limit is wrong"); |
| ParallelScavengeHeap* heap = (ParallelScavengeHeap*)Universe::heap(); |
| size_t result = gen_size_limit() - current_committed_size; |
| size_t result_aligned = align_size_down(result, heap->generation_alignment()); |
| return result_aligned; |
| } |
| |
| // Return the number of bytes the young gen is willing give up. |
| // |
| // Future implementations could check the survivors and if to_space is in the |
| // right place (below from_space), take a chunk from to_space. |
| size_t ASPSYoungGen::available_for_contraction() { |
| size_t uncommitted_bytes = virtual_space()->uncommitted_size(); |
| if (uncommitted_bytes != 0) { |
| return uncommitted_bytes; |
| } |
| |
| if (eden_space()->is_empty()) { |
| // Respect the minimum size for eden and for the young gen as a whole. |
| ParallelScavengeHeap* heap = (ParallelScavengeHeap*)Universe::heap(); |
| const size_t eden_alignment = heap->space_alignment(); |
| const size_t gen_alignment = heap->generation_alignment(); |
| |
| assert(eden_space()->capacity_in_bytes() >= eden_alignment, |
| "Alignment is wrong"); |
| size_t eden_avail = eden_space()->capacity_in_bytes() - eden_alignment; |
| eden_avail = align_size_down(eden_avail, gen_alignment); |
| |
| assert(virtual_space()->committed_size() >= min_gen_size(), |
| "minimum gen size is wrong"); |
| size_t gen_avail = virtual_space()->committed_size() - min_gen_size(); |
| assert(virtual_space()->is_aligned(gen_avail), "not aligned"); |
| |
| const size_t max_contraction = MIN2(eden_avail, gen_avail); |
| // See comment for ASPSOldGen::available_for_contraction() |
| // for reasons the "increment" fraction is used. |
| PSAdaptiveSizePolicy* policy = heap->size_policy(); |
| size_t result = policy->eden_increment_aligned_down(max_contraction); |
| size_t result_aligned = align_size_down(result, gen_alignment); |
| if (PrintAdaptiveSizePolicy && Verbose) { |
| gclog_or_tty->print_cr("ASPSYoungGen::available_for_contraction: " SIZE_FORMAT " K", |
| result_aligned/K); |
| gclog_or_tty->print_cr(" max_contraction " SIZE_FORMAT " K", max_contraction/K); |
| gclog_or_tty->print_cr(" eden_avail " SIZE_FORMAT " K", eden_avail/K); |
| gclog_or_tty->print_cr(" gen_avail " SIZE_FORMAT " K", gen_avail/K); |
| } |
| return result_aligned; |
| } |
| |
| return 0; |
| } |
| |
| // The current implementation only considers to the end of eden. |
| // If to_space is below from_space, to_space is not considered. |
| // to_space can be. |
| size_t ASPSYoungGen::available_to_live() { |
| ParallelScavengeHeap* heap = (ParallelScavengeHeap*)Universe::heap(); |
| const size_t alignment = heap->space_alignment(); |
| |
| // Include any space that is committed but is not in eden. |
| size_t available = pointer_delta(eden_space()->bottom(), |
| virtual_space()->low(), |
| sizeof(char)); |
| |
| const size_t eden_capacity = eden_space()->capacity_in_bytes(); |
| if (eden_space()->is_empty() && eden_capacity > alignment) { |
| available += eden_capacity - alignment; |
| } |
| return available; |
| } |
| |
| // Similar to PSYoungGen::resize_generation() but |
| // allows sum of eden_size and 2 * survivor_size to exceed _max_gen_size |
| // expands at the low end of the virtual space |
| // moves the boundary between the generations in order to expand |
| // some additional diagnostics |
| // If no additional changes are required, this can be deleted |
| // and the changes factored back into PSYoungGen::resize_generation(). |
| bool ASPSYoungGen::resize_generation(size_t eden_size, size_t survivor_size) { |
| const size_t alignment = virtual_space()->alignment(); |
| size_t orig_size = virtual_space()->committed_size(); |
| bool size_changed = false; |
| |
| // There used to be a guarantee here that |
| // (eden_size + 2*survivor_size) <= _max_gen_size |
| // This requirement is enforced by the calculation of desired_size |
| // below. It may not be true on entry since the size of the |
| // eden_size is no bounded by the generation size. |
| |
| assert(max_size() == reserved().byte_size(), "max gen size problem?"); |
| assert(min_gen_size() <= orig_size && orig_size <= max_size(), |
| "just checking"); |
| |
| // Adjust new generation size |
| const size_t eden_plus_survivors = |
| align_size_up(eden_size + 2 * survivor_size, alignment); |
| size_t desired_size = MAX2(MIN2(eden_plus_survivors, gen_size_limit()), |
| min_gen_size()); |
| assert(desired_size <= gen_size_limit(), "just checking"); |
| |
| if (desired_size > orig_size) { |
| // Grow the generation |
| size_t change = desired_size - orig_size; |
| HeapWord* prev_low = (HeapWord*) virtual_space()->low(); |
| if (!virtual_space()->expand_by(change)) { |
| return false; |
| } |
| if (ZapUnusedHeapArea) { |
| // Mangle newly committed space immediately because it |
| // can be done here more simply that after the new |
| // spaces have been computed. |
| HeapWord* new_low = (HeapWord*) virtual_space()->low(); |
| assert(new_low < prev_low, "Did not grow"); |
| |
| MemRegion mangle_region(new_low, prev_low); |
| SpaceMangler::mangle_region(mangle_region); |
| } |
| size_changed = true; |
| } else if (desired_size < orig_size) { |
| size_t desired_change = orig_size - desired_size; |
| |
| // How much is available for shrinking. |
| size_t available_bytes = limit_gen_shrink(desired_change); |
| size_t change = MIN2(desired_change, available_bytes); |
| virtual_space()->shrink_by(change); |
| size_changed = true; |
| } else { |
| if (Verbose && PrintGC) { |
| if (orig_size == gen_size_limit()) { |
| gclog_or_tty->print_cr("ASPSYoung generation size at maximum: " |
| SIZE_FORMAT "K", orig_size/K); |
| } else if (orig_size == min_gen_size()) { |
| gclog_or_tty->print_cr("ASPSYoung generation size at minium: " |
| SIZE_FORMAT "K", orig_size/K); |
| } |
| } |
| } |
| |
| if (size_changed) { |
| reset_after_change(); |
| if (Verbose && PrintGC) { |
| size_t current_size = virtual_space()->committed_size(); |
| gclog_or_tty->print_cr("ASPSYoung generation size changed: " |
| SIZE_FORMAT "K->" SIZE_FORMAT "K", |
| orig_size/K, current_size/K); |
| } |
| } |
| |
| guarantee(eden_plus_survivors <= virtual_space()->committed_size() || |
| virtual_space()->committed_size() == max_size(), "Sanity"); |
| |
| return true; |
| } |
| |
| // Similar to PSYoungGen::resize_spaces() but |
| // eden always starts at the low end of the committed virtual space |
| // current implementation does not allow holes between the spaces |
| // _young_generation_boundary has to be reset because it changes. |
| // so additional verification |
| |
| void ASPSYoungGen::resize_spaces(size_t requested_eden_size, |
| size_t requested_survivor_size) { |
| assert(UseAdaptiveSizePolicy, "sanity check"); |
| assert(requested_eden_size > 0 && requested_survivor_size > 0, |
| "just checking"); |
| |
| space_invariants(); |
| |
| // We require eden and to space to be empty |
| if ((!eden_space()->is_empty()) || (!to_space()->is_empty())) { |
| return; |
| } |
| |
| if (PrintAdaptiveSizePolicy && Verbose) { |
| gclog_or_tty->print_cr("PSYoungGen::resize_spaces(requested_eden_size: " |
| SIZE_FORMAT |
| ", requested_survivor_size: " SIZE_FORMAT ")", |
| requested_eden_size, requested_survivor_size); |
| gclog_or_tty->print_cr(" eden: [" PTR_FORMAT ".." PTR_FORMAT ") " |
| SIZE_FORMAT, |
| p2i(eden_space()->bottom()), |
| p2i(eden_space()->end()), |
| pointer_delta(eden_space()->end(), |
| eden_space()->bottom(), |
| sizeof(char))); |
| gclog_or_tty->print_cr(" from: [" PTR_FORMAT ".." PTR_FORMAT ") " |
| SIZE_FORMAT, |
| p2i(from_space()->bottom()), |
| p2i(from_space()->end()), |
| pointer_delta(from_space()->end(), |
| from_space()->bottom(), |
| sizeof(char))); |
| gclog_or_tty->print_cr(" to: [" PTR_FORMAT ".." PTR_FORMAT ") " |
| SIZE_FORMAT, |
| p2i(to_space()->bottom()), |
| p2i(to_space()->end()), |
| pointer_delta( to_space()->end(), |
| to_space()->bottom(), |
| sizeof(char))); |
| } |
| |
| // There's nothing to do if the new sizes are the same as the current |
| if (requested_survivor_size == to_space()->capacity_in_bytes() && |
| requested_survivor_size == from_space()->capacity_in_bytes() && |
| requested_eden_size == eden_space()->capacity_in_bytes()) { |
| if (PrintAdaptiveSizePolicy && Verbose) { |
| gclog_or_tty->print_cr(" capacities are the right sizes, returning"); |
| } |
| return; |
| } |
| |
| char* eden_start = (char*)virtual_space()->low(); |
| char* eden_end = (char*)eden_space()->end(); |
| char* from_start = (char*)from_space()->bottom(); |
| char* from_end = (char*)from_space()->end(); |
| char* to_start = (char*)to_space()->bottom(); |
| char* to_end = (char*)to_space()->end(); |
| |
| assert(eden_start < from_start, "Cannot push into from_space"); |
| |
| ParallelScavengeHeap* heap = (ParallelScavengeHeap*)Universe::heap(); |
| const size_t alignment = heap->space_alignment(); |
| const bool maintain_minimum = |
| (requested_eden_size + 2 * requested_survivor_size) <= min_gen_size(); |
| |
| bool eden_from_to_order = from_start < to_start; |
| // Check whether from space is below to space |
| if (eden_from_to_order) { |
| // Eden, from, to |
| |
| if (PrintAdaptiveSizePolicy && Verbose) { |
| gclog_or_tty->print_cr(" Eden, from, to:"); |
| } |
| |
| // Set eden |
| // "requested_eden_size" is a goal for the size of eden |
| // and may not be attainable. "eden_size" below is |
| // calculated based on the location of from-space and |
| // the goal for the size of eden. from-space is |
| // fixed in place because it contains live data. |
| // The calculation is done this way to avoid 32bit |
| // overflow (i.e., eden_start + requested_eden_size |
| // may too large for representation in 32bits). |
| size_t eden_size; |
| if (maintain_minimum) { |
| // Only make eden larger than the requested size if |
| // the minimum size of the generation has to be maintained. |
| // This could be done in general but policy at a higher |
| // level is determining a requested size for eden and that |
| // should be honored unless there is a fundamental reason. |
| eden_size = pointer_delta(from_start, |
| eden_start, |
| sizeof(char)); |
| } else { |
| eden_size = MIN2(requested_eden_size, |
| pointer_delta(from_start, eden_start, sizeof(char))); |
| } |
| |
| eden_end = eden_start + eden_size; |
| assert(eden_end >= eden_start, "addition overflowed"); |
| |
| // To may resize into from space as long as it is clear of live data. |
| // From space must remain page aligned, though, so we need to do some |
| // extra calculations. |
| |
| // First calculate an optimal to-space |
| to_end = (char*)virtual_space()->high(); |
| to_start = (char*)pointer_delta(to_end, |
| (char*)requested_survivor_size, |
| sizeof(char)); |
| |
| // Does the optimal to-space overlap from-space? |
| if (to_start < (char*)from_space()->end()) { |
| assert(heap->kind() == CollectedHeap::ParallelScavengeHeap, "Sanity"); |
| |
| // Calculate the minimum offset possible for from_end |
| size_t from_size = |
| pointer_delta(from_space()->top(), from_start, sizeof(char)); |
| |
| // Should we be in this method if from_space is empty? Why not the set_space method? FIX ME! |
| if (from_size == 0) { |
| from_size = alignment; |
| } else { |
| from_size = align_size_up(from_size, alignment); |
| } |
| |
| from_end = from_start + from_size; |
| assert(from_end > from_start, "addition overflow or from_size problem"); |
| |
| guarantee(from_end <= (char*)from_space()->end(), |
| "from_end moved to the right"); |
| |
| // Now update to_start with the new from_end |
| to_start = MAX2(from_end, to_start); |
| } |
| |
| guarantee(to_start != to_end, "to space is zero sized"); |
| |
| if (PrintAdaptiveSizePolicy && Verbose) { |
| gclog_or_tty->print_cr(" [eden_start .. eden_end): " |
| "[" PTR_FORMAT " .. " PTR_FORMAT ") " SIZE_FORMAT, |
| p2i(eden_start), |
| p2i(eden_end), |
| pointer_delta(eden_end, eden_start, sizeof(char))); |
| gclog_or_tty->print_cr(" [from_start .. from_end): " |
| "[" PTR_FORMAT " .. " PTR_FORMAT ") " SIZE_FORMAT, |
| p2i(from_start), |
| p2i(from_end), |
| pointer_delta(from_end, from_start, sizeof(char))); |
| gclog_or_tty->print_cr(" [ to_start .. to_end): " |
| "[" PTR_FORMAT " .. " PTR_FORMAT ") " SIZE_FORMAT, |
| p2i(to_start), |
| p2i(to_end), |
| pointer_delta( to_end, to_start, sizeof(char))); |
| } |
| } else { |
| // Eden, to, from |
| if (PrintAdaptiveSizePolicy && Verbose) { |
| gclog_or_tty->print_cr(" Eden, to, from:"); |
| } |
| |
| // To space gets priority over eden resizing. Note that we position |
| // to space as if we were able to resize from space, even though from |
| // space is not modified. |
| // Giving eden priority was tried and gave poorer performance. |
| to_end = (char*)pointer_delta(virtual_space()->high(), |
| (char*)requested_survivor_size, |
| sizeof(char)); |
| to_end = MIN2(to_end, from_start); |
| to_start = (char*)pointer_delta(to_end, (char*)requested_survivor_size, |
| sizeof(char)); |
| // if the space sizes are to be increased by several times then |
| // 'to_start' will point beyond the young generation. In this case |
| // 'to_start' should be adjusted. |
| to_start = MAX2(to_start, eden_start + alignment); |
| |
| // Compute how big eden can be, then adjust end. |
| // See comments above on calculating eden_end. |
| size_t eden_size; |
| if (maintain_minimum) { |
| eden_size = pointer_delta(to_start, eden_start, sizeof(char)); |
| } else { |
| eden_size = MIN2(requested_eden_size, |
| pointer_delta(to_start, eden_start, sizeof(char))); |
| } |
| eden_end = eden_start + eden_size; |
| assert(eden_end >= eden_start, "addition overflowed"); |
| |
| // Don't let eden shrink down to 0 or less. |
| eden_end = MAX2(eden_end, eden_start + alignment); |
| to_start = MAX2(to_start, eden_end); |
| |
| if (PrintAdaptiveSizePolicy && Verbose) { |
| gclog_or_tty->print_cr(" [eden_start .. eden_end): " |
| "[" PTR_FORMAT " .. " PTR_FORMAT ") " SIZE_FORMAT, |
| p2i(eden_start), |
| p2i(eden_end), |
| pointer_delta(eden_end, eden_start, sizeof(char))); |
| gclog_or_tty->print_cr(" [ to_start .. to_end): " |
| "[" PTR_FORMAT " .. " PTR_FORMAT ") " SIZE_FORMAT, |
| p2i(to_start), |
| p2i(to_end), |
| pointer_delta( to_end, to_start, sizeof(char))); |
| gclog_or_tty->print_cr(" [from_start .. from_end): " |
| "[" PTR_FORMAT " .. " PTR_FORMAT ") " SIZE_FORMAT, |
| p2i(from_start), |
| p2i(from_end), |
| pointer_delta(from_end, from_start, sizeof(char))); |
| } |
| } |
| |
| |
| guarantee((HeapWord*)from_start <= from_space()->bottom(), |
| "from start moved to the right"); |
| guarantee((HeapWord*)from_end >= from_space()->top(), |
| "from end moved into live data"); |
| assert(is_object_aligned((intptr_t)eden_start), "checking alignment"); |
| assert(is_object_aligned((intptr_t)from_start), "checking alignment"); |
| assert(is_object_aligned((intptr_t)to_start), "checking alignment"); |
| |
| MemRegion edenMR((HeapWord*)eden_start, (HeapWord*)eden_end); |
| MemRegion toMR ((HeapWord*)to_start, (HeapWord*)to_end); |
| MemRegion fromMR((HeapWord*)from_start, (HeapWord*)from_end); |
| |
| // Let's make sure the call to initialize doesn't reset "top"! |
| DEBUG_ONLY(HeapWord* old_from_top = from_space()->top();) |
| |
| // For PrintAdaptiveSizePolicy block below |
| size_t old_from = from_space()->capacity_in_bytes(); |
| size_t old_to = to_space()->capacity_in_bytes(); |
| |
| if (ZapUnusedHeapArea) { |
| // NUMA is a special case because a numa space is not mangled |
| // in order to not prematurely bind its address to memory to |
| // the wrong memory (i.e., don't want the GC thread to first |
| // touch the memory). The survivor spaces are not numa |
| // spaces and are mangled. |
| if (UseNUMA) { |
| if (eden_from_to_order) { |
| mangle_survivors(from_space(), fromMR, to_space(), toMR); |
| } else { |
| mangle_survivors(to_space(), toMR, from_space(), fromMR); |
| } |
| } |
| |
| // If not mangling the spaces, do some checking to verify that |
| // the spaces are already mangled. |
| // The spaces should be correctly mangled at this point so |
| // do some checking here. Note that they are not being mangled |
| // in the calls to initialize(). |
| // Must check mangling before the spaces are reshaped. Otherwise, |
| // the bottom or end of one space may have moved into an area |
| // covered by another space and a failure of the check may |
| // not correctly indicate which space is not properly mangled. |
| |
| HeapWord* limit = (HeapWord*) virtual_space()->high(); |
| eden_space()->check_mangled_unused_area(limit); |
| from_space()->check_mangled_unused_area(limit); |
| to_space()->check_mangled_unused_area(limit); |
| } |
| // When an existing space is being initialized, it is not |
| // mangled because the space has been previously mangled. |
| eden_space()->initialize(edenMR, |
| SpaceDecorator::Clear, |
| SpaceDecorator::DontMangle); |
| to_space()->initialize(toMR, |
| SpaceDecorator::Clear, |
| SpaceDecorator::DontMangle); |
| from_space()->initialize(fromMR, |
| SpaceDecorator::DontClear, |
| SpaceDecorator::DontMangle); |
| |
| PSScavenge::set_young_generation_boundary(eden_space()->bottom()); |
| |
| assert(from_space()->top() == old_from_top, "from top changed!"); |
| |
| if (PrintAdaptiveSizePolicy) { |
| ParallelScavengeHeap* heap = (ParallelScavengeHeap*)Universe::heap(); |
| assert(heap->kind() == CollectedHeap::ParallelScavengeHeap, "Sanity"); |
| |
| gclog_or_tty->print("AdaptiveSizePolicy::survivor space sizes: " |
| "collection: %d " |
| "(" SIZE_FORMAT ", " SIZE_FORMAT ") -> " |
| "(" SIZE_FORMAT ", " SIZE_FORMAT ") ", |
| heap->total_collections(), |
| old_from, old_to, |
| from_space()->capacity_in_bytes(), |
| to_space()->capacity_in_bytes()); |
| gclog_or_tty->cr(); |
| } |
| space_invariants(); |
| } |
| void ASPSYoungGen::reset_after_change() { |
| assert_locked_or_safepoint(Heap_lock); |
| |
| _reserved = MemRegion((HeapWord*)virtual_space()->low_boundary(), |
| (HeapWord*)virtual_space()->high_boundary()); |
| PSScavenge::reference_processor()->set_span(_reserved); |
| |
| HeapWord* new_eden_bottom = (HeapWord*)virtual_space()->low(); |
| HeapWord* eden_bottom = eden_space()->bottom(); |
| if (new_eden_bottom != eden_bottom) { |
| MemRegion eden_mr(new_eden_bottom, eden_space()->end()); |
| eden_space()->initialize(eden_mr, |
| SpaceDecorator::Clear, |
| SpaceDecorator::Mangle); |
| PSScavenge::set_young_generation_boundary(eden_space()->bottom()); |
| } |
| MemRegion cmr((HeapWord*)virtual_space()->low(), |
| (HeapWord*)virtual_space()->high()); |
| Universe::heap()->barrier_set()->resize_covered_region(cmr); |
| |
| space_invariants(); |
| } |
