| /* |
| * Copyright (c) 2014, 2017, 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/g1/g1PageBasedVirtualSpace.hpp" |
| #include "gc/shared/workgroup.hpp" |
| #include "oops/markOop.hpp" |
| #include "oops/oop.inline.hpp" |
| #include "runtime/atomic.hpp" |
| #include "runtime/os.inline.hpp" |
| #include "services/memTracker.hpp" |
| #include "utilities/align.hpp" |
| #include "utilities/bitMap.inline.hpp" |
| |
| G1PageBasedVirtualSpace::G1PageBasedVirtualSpace(ReservedSpace rs, size_t used_size, size_t page_size) : |
| _low_boundary(NULL), _high_boundary(NULL), _committed(mtGC), _page_size(0), _special(false), |
| _dirty(mtGC), _executable(false) { |
| initialize_with_page_size(rs, used_size, page_size); |
| } |
| |
| void G1PageBasedVirtualSpace::initialize_with_page_size(ReservedSpace rs, size_t used_size, size_t page_size) { |
| guarantee(rs.is_reserved(), "Given reserved space must have been reserved already."); |
| |
| vmassert(_low_boundary == NULL, "VirtualSpace already initialized"); |
| vmassert(page_size > 0, "Page size must be non-zero."); |
| |
| guarantee(is_aligned(rs.base(), page_size), |
| "Reserved space base " PTR_FORMAT " is not aligned to requested page size " SIZE_FORMAT, p2i(rs.base()), page_size); |
| guarantee(is_aligned(used_size, os::vm_page_size()), |
| "Given used reserved space size needs to be OS page size aligned (%d bytes) but is " SIZE_FORMAT, os::vm_page_size(), used_size); |
| guarantee(used_size <= rs.size(), |
| "Used size of reserved space " SIZE_FORMAT " bytes is smaller than reservation at " SIZE_FORMAT " bytes", used_size, rs.size()); |
| guarantee(is_aligned(rs.size(), page_size), |
| "Expected that the virtual space is size aligned, but " SIZE_FORMAT " is not aligned to page size " SIZE_FORMAT, rs.size(), page_size); |
| |
| _low_boundary = rs.base(); |
| _high_boundary = _low_boundary + used_size; |
| |
| _special = rs.special(); |
| _executable = rs.executable(); |
| |
| _page_size = page_size; |
| |
| vmassert(_committed.size() == 0, "virtual space initialized more than once"); |
| BitMap::idx_t size_in_pages = rs.size() / page_size; |
| _committed.initialize(size_in_pages); |
| if (_special) { |
| _dirty.initialize(size_in_pages); |
| } |
| |
| _tail_size = used_size % _page_size; |
| } |
| |
| G1PageBasedVirtualSpace::~G1PageBasedVirtualSpace() { |
| // This does not release memory it never reserved. |
| // Caller must release via rs.release(); |
| _low_boundary = NULL; |
| _high_boundary = NULL; |
| _special = false; |
| _executable = false; |
| _page_size = 0; |
| _tail_size = 0; |
| } |
| |
| size_t G1PageBasedVirtualSpace::committed_size() const { |
| size_t result = _committed.count_one_bits() * _page_size; |
| // The last page might not be in full. |
| if (is_last_page_partial() && _committed.at(_committed.size() - 1)) { |
| result -= _page_size - _tail_size; |
| } |
| return result; |
| } |
| |
| size_t G1PageBasedVirtualSpace::reserved_size() const { |
| return pointer_delta(_high_boundary, _low_boundary, sizeof(char)); |
| } |
| |
| size_t G1PageBasedVirtualSpace::uncommitted_size() const { |
| return reserved_size() - committed_size(); |
| } |
| |
| size_t G1PageBasedVirtualSpace::addr_to_page_index(char* addr) const { |
| return (addr - _low_boundary) / _page_size; |
| } |
| |
| bool G1PageBasedVirtualSpace::is_area_committed(size_t start_page, size_t size_in_pages) const { |
| size_t end_page = start_page + size_in_pages; |
| return _committed.get_next_zero_offset(start_page, end_page) >= end_page; |
| } |
| |
| bool G1PageBasedVirtualSpace::is_area_uncommitted(size_t start_page, size_t size_in_pages) const { |
| size_t end_page = start_page + size_in_pages; |
| return _committed.get_next_one_offset(start_page, end_page) >= end_page; |
| } |
| |
| char* G1PageBasedVirtualSpace::page_start(size_t index) const { |
| return _low_boundary + index * _page_size; |
| } |
| |
| bool G1PageBasedVirtualSpace::is_after_last_page(size_t index) const { |
| guarantee(index <= _committed.size(), |
| "Given boundary page " SIZE_FORMAT " is beyond managed page count " SIZE_FORMAT, index, _committed.size()); |
| return index == _committed.size(); |
| } |
| |
| void G1PageBasedVirtualSpace::commit_preferred_pages(size_t start, size_t num_pages) { |
| vmassert(num_pages > 0, "No full pages to commit"); |
| vmassert(start + num_pages <= _committed.size(), |
| "Tried to commit area from page " SIZE_FORMAT " to page " SIZE_FORMAT " " |
| "that is outside of managed space of " SIZE_FORMAT " pages", |
| start, start + num_pages, _committed.size()); |
| |
| char* start_addr = page_start(start); |
| size_t size = num_pages * _page_size; |
| |
| os::commit_memory_or_exit(start_addr, size, _page_size, _executable, |
| err_msg("Failed to commit area from " PTR_FORMAT " to " PTR_FORMAT " of length " SIZE_FORMAT ".", |
| p2i(start_addr), p2i(start_addr + size), size)); |
| } |
| |
| void G1PageBasedVirtualSpace::commit_tail() { |
| vmassert(_tail_size > 0, "The size of the tail area must be > 0 when reaching here"); |
| |
| char* const aligned_end_address = align_down(_high_boundary, _page_size); |
| os::commit_memory_or_exit(aligned_end_address, _tail_size, os::vm_page_size(), _executable, |
| err_msg("Failed to commit tail area from " PTR_FORMAT " to " PTR_FORMAT " of length " SIZE_FORMAT ".", |
| p2i(aligned_end_address), p2i(_high_boundary), _tail_size)); |
| } |
| |
| void G1PageBasedVirtualSpace::commit_internal(size_t start_page, size_t end_page) { |
| guarantee(start_page < end_page, |
| "Given start page " SIZE_FORMAT " is larger or equal to end page " SIZE_FORMAT, start_page, end_page); |
| guarantee(end_page <= _committed.size(), |
| "Given end page " SIZE_FORMAT " is beyond end of managed page amount of " SIZE_FORMAT, end_page, _committed.size()); |
| |
| size_t pages = end_page - start_page; |
| bool need_to_commit_tail = is_after_last_page(end_page) && is_last_page_partial(); |
| |
| // If we have to commit some (partial) tail area, decrease the amount of pages to avoid |
| // committing that in the full-page commit code. |
| if (need_to_commit_tail) { |
| pages--; |
| } |
| |
| if (pages > 0) { |
| commit_preferred_pages(start_page, pages); |
| } |
| |
| if (need_to_commit_tail) { |
| commit_tail(); |
| } |
| } |
| |
| char* G1PageBasedVirtualSpace::bounded_end_addr(size_t end_page) const { |
| return MIN2(_high_boundary, page_start(end_page)); |
| } |
| |
| void G1PageBasedVirtualSpace::pretouch_internal(size_t start_page, size_t end_page) { |
| guarantee(start_page < end_page, |
| "Given start page " SIZE_FORMAT " is larger or equal to end page " SIZE_FORMAT, start_page, end_page); |
| |
| os::pretouch_memory(page_start(start_page), bounded_end_addr(end_page), _page_size); |
| } |
| |
| bool G1PageBasedVirtualSpace::commit(size_t start_page, size_t size_in_pages) { |
| // We need to make sure to commit all pages covered by the given area. |
| guarantee(is_area_uncommitted(start_page, size_in_pages), "Specified area is not uncommitted"); |
| |
| bool zero_filled = true; |
| size_t end_page = start_page + size_in_pages; |
| |
| if (_special) { |
| // Check for dirty pages and update zero_filled if any found. |
| if (_dirty.get_next_one_offset(start_page, end_page) < end_page) { |
| zero_filled = false; |
| _dirty.clear_range(start_page, end_page); |
| } |
| } else { |
| commit_internal(start_page, end_page); |
| } |
| _committed.set_range(start_page, end_page); |
| |
| return zero_filled; |
| } |
| |
| void G1PageBasedVirtualSpace::uncommit_internal(size_t start_page, size_t end_page) { |
| guarantee(start_page < end_page, |
| "Given start page " SIZE_FORMAT " is larger or equal to end page " SIZE_FORMAT, start_page, end_page); |
| |
| char* start_addr = page_start(start_page); |
| os::uncommit_memory(start_addr, pointer_delta(bounded_end_addr(end_page), start_addr, sizeof(char))); |
| } |
| |
| void G1PageBasedVirtualSpace::uncommit(size_t start_page, size_t size_in_pages) { |
| guarantee(is_area_committed(start_page, size_in_pages), "checking"); |
| |
| size_t end_page = start_page + size_in_pages; |
| if (_special) { |
| // Mark that memory is dirty. If committed again the memory might |
| // need to be cleared explicitly. |
| _dirty.set_range(start_page, end_page); |
| } else { |
| uncommit_internal(start_page, end_page); |
| } |
| |
| _committed.clear_range(start_page, end_page); |
| } |
| |
| class G1PretouchTask : public AbstractGangTask { |
| private: |
| char* volatile _cur_addr; |
| char* const _start_addr; |
| char* const _end_addr; |
| size_t const _page_size; |
| public: |
| G1PretouchTask(char* start_address, char* end_address, size_t page_size) : |
| AbstractGangTask("G1 PreTouch", |
| Universe::is_fully_initialized() && |
| Thread::current()->is_Named_thread() ? GCId::current_raw() : |
| // During VM initialization there is |
| // no GC cycle that this task can be |
| // associated with. |
| GCId::undefined()), |
| _cur_addr(start_address), |
| _start_addr(start_address), |
| _end_addr(end_address), |
| _page_size(page_size) { |
| } |
| |
| virtual void work(uint worker_id) { |
| size_t const actual_chunk_size = MAX2(chunk_size(), _page_size); |
| while (true) { |
| char* touch_addr = (char*)Atomic::add_ptr((intptr_t)actual_chunk_size, (volatile void*) &_cur_addr) - actual_chunk_size; |
| if (touch_addr < _start_addr || touch_addr >= _end_addr) { |
| break; |
| } |
| char* end_addr = touch_addr + MIN2(actual_chunk_size, pointer_delta(_end_addr, touch_addr, sizeof(char))); |
| os::pretouch_memory(touch_addr, end_addr, _page_size); |
| } |
| } |
| |
| static size_t chunk_size() { return PreTouchParallelChunkSize; } |
| }; |
| |
| void G1PageBasedVirtualSpace::pretouch(size_t start_page, size_t size_in_pages, WorkGang* pretouch_gang) { |
| G1PretouchTask cl(page_start(start_page), bounded_end_addr(start_page + size_in_pages), _page_size); |
| |
| if (pretouch_gang != NULL) { |
| size_t num_chunks = MAX2((size_t)1, size_in_pages * _page_size / MAX2(G1PretouchTask::chunk_size(), _page_size)); |
| |
| uint num_workers = MIN2((uint)num_chunks, pretouch_gang->active_workers()); |
| log_debug(gc, heap)("Running %s with %u workers for " SIZE_FORMAT " work units pre-touching " SIZE_FORMAT "B.", |
| cl.name(), num_workers, num_chunks, size_in_pages * _page_size); |
| pretouch_gang->run_task(&cl, num_workers); |
| } else { |
| log_debug(gc, heap)("Running %s pre-touching " SIZE_FORMAT "B.", |
| cl.name(), size_in_pages * _page_size); |
| cl.work(0); |
| } |
| } |
| |
| bool G1PageBasedVirtualSpace::contains(const void* p) const { |
| return _low_boundary <= (const char*) p && (const char*) p < _high_boundary; |
| } |
| |
| #ifndef PRODUCT |
| void G1PageBasedVirtualSpace::print_on(outputStream* out) { |
| out->print ("Virtual space:"); |
| if (_special) out->print(" (pinned in memory)"); |
| out->cr(); |
| out->print_cr(" - committed: " SIZE_FORMAT, committed_size()); |
| out->print_cr(" - reserved: " SIZE_FORMAT, reserved_size()); |
| out->print_cr(" - preferred page size: " SIZE_FORMAT, _page_size); |
| out->print_cr(" - [low_b, high_b]: [" PTR_FORMAT ", " PTR_FORMAT "]", p2i(_low_boundary), p2i(_high_boundary)); |
| } |
| |
| void G1PageBasedVirtualSpace::print() { |
| print_on(tty); |
| } |
| #endif |