Fri, 18 Feb 2011 10:07:34 -0800
7020042: G1: Partially remove fix for 6994628
Summary: Disable reference discovery and processing during concurrent marking by disabling fix for 6994628.
Reviewed-by: tonyp, ysr
tonyp@2715 | 1 | /* |
tonyp@2715 | 2 | * Copyright (c) 2011, Oracle and/or its affiliates. All rights reserved. |
tonyp@2715 | 3 | * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
tonyp@2715 | 4 | * |
tonyp@2715 | 5 | * This code is free software; you can redistribute it and/or modify it |
tonyp@2715 | 6 | * under the terms of the GNU General Public License version 2 only, as |
tonyp@2715 | 7 | * published by the Free Software Foundation. |
tonyp@2715 | 8 | * |
tonyp@2715 | 9 | * This code is distributed in the hope that it will be useful, but WITHOUT |
tonyp@2715 | 10 | * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
tonyp@2715 | 11 | * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
tonyp@2715 | 12 | * version 2 for more details (a copy is included in the LICENSE file that |
tonyp@2715 | 13 | * accompanied this code). |
tonyp@2715 | 14 | * |
tonyp@2715 | 15 | * You should have received a copy of the GNU General Public License version |
tonyp@2715 | 16 | * 2 along with this work; if not, write to the Free Software Foundation, |
tonyp@2715 | 17 | * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. |
tonyp@2715 | 18 | * |
tonyp@2715 | 19 | * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA |
tonyp@2715 | 20 | * or visit www.oracle.com if you need additional information or have any |
tonyp@2715 | 21 | * questions. |
tonyp@2715 | 22 | * |
tonyp@2715 | 23 | */ |
tonyp@2715 | 24 | |
tonyp@2715 | 25 | #include "precompiled.hpp" |
tonyp@2715 | 26 | #include "gc_implementation/g1/g1AllocRegion.inline.hpp" |
tonyp@2715 | 27 | #include "gc_implementation/g1/g1CollectedHeap.inline.hpp" |
tonyp@2715 | 28 | |
tonyp@2715 | 29 | G1CollectedHeap* G1AllocRegion::_g1h = NULL; |
tonyp@2715 | 30 | HeapRegion* G1AllocRegion::_dummy_region = NULL; |
tonyp@2715 | 31 | |
tonyp@2715 | 32 | void G1AllocRegion::setup(G1CollectedHeap* g1h, HeapRegion* dummy_region) { |
tonyp@2715 | 33 | assert(_dummy_region == NULL, "should be set once"); |
tonyp@2715 | 34 | assert(dummy_region != NULL, "pre-condition"); |
tonyp@2715 | 35 | assert(dummy_region->free() == 0, "pre-condition"); |
tonyp@2715 | 36 | |
tonyp@2715 | 37 | // Make sure that any allocation attempt on this region will fail |
tonyp@2715 | 38 | // and will not trigger any asserts. |
tonyp@2715 | 39 | assert(allocate(dummy_region, 1, false) == NULL, "should fail"); |
tonyp@2715 | 40 | assert(par_allocate(dummy_region, 1, false) == NULL, "should fail"); |
tonyp@2715 | 41 | assert(allocate(dummy_region, 1, true) == NULL, "should fail"); |
tonyp@2715 | 42 | assert(par_allocate(dummy_region, 1, true) == NULL, "should fail"); |
tonyp@2715 | 43 | |
tonyp@2715 | 44 | _g1h = g1h; |
tonyp@2715 | 45 | _dummy_region = dummy_region; |
tonyp@2715 | 46 | } |
tonyp@2715 | 47 | |
tonyp@2715 | 48 | void G1AllocRegion::fill_up_remaining_space(HeapRegion* alloc_region, |
tonyp@2715 | 49 | bool bot_updates) { |
tonyp@2715 | 50 | assert(alloc_region != NULL && alloc_region != _dummy_region, |
tonyp@2715 | 51 | "pre-condition"); |
tonyp@2715 | 52 | |
tonyp@2715 | 53 | // Other threads might still be trying to allocate using a CAS out |
tonyp@2715 | 54 | // of the region we are trying to retire, as they can do so without |
tonyp@2715 | 55 | // holding the lock. So, we first have to make sure that noone else |
tonyp@2715 | 56 | // can allocate out of it by doing a maximal allocation. Even if our |
tonyp@2715 | 57 | // CAS attempt fails a few times, we'll succeed sooner or later |
tonyp@2715 | 58 | // given that failed CAS attempts mean that the region is getting |
tonyp@2715 | 59 | // closed to being full. |
tonyp@2715 | 60 | size_t free_word_size = alloc_region->free() / HeapWordSize; |
tonyp@2715 | 61 | |
tonyp@2715 | 62 | // This is the minimum free chunk we can turn into a dummy |
tonyp@2715 | 63 | // object. If the free space falls below this, then noone can |
tonyp@2715 | 64 | // allocate in this region anyway (all allocation requests will be |
tonyp@2715 | 65 | // of a size larger than this) so we won't have to perform the dummy |
tonyp@2715 | 66 | // allocation. |
tonyp@2715 | 67 | size_t min_word_size_to_fill = CollectedHeap::min_fill_size(); |
tonyp@2715 | 68 | |
tonyp@2715 | 69 | while (free_word_size >= min_word_size_to_fill) { |
tonyp@2715 | 70 | HeapWord* dummy = par_allocate(alloc_region, free_word_size, bot_updates); |
tonyp@2715 | 71 | if (dummy != NULL) { |
tonyp@2715 | 72 | // If the allocation was successful we should fill in the space. |
tonyp@2715 | 73 | CollectedHeap::fill_with_object(dummy, free_word_size); |
tonyp@2715 | 74 | alloc_region->set_pre_dummy_top(dummy); |
tonyp@2715 | 75 | break; |
tonyp@2715 | 76 | } |
tonyp@2715 | 77 | |
tonyp@2715 | 78 | free_word_size = alloc_region->free() / HeapWordSize; |
tonyp@2715 | 79 | // It's also possible that someone else beats us to the |
tonyp@2715 | 80 | // allocation and they fill up the region. In that case, we can |
tonyp@2715 | 81 | // just get out of the loop. |
tonyp@2715 | 82 | } |
tonyp@2715 | 83 | assert(alloc_region->free() / HeapWordSize < min_word_size_to_fill, |
tonyp@2715 | 84 | "post-condition"); |
tonyp@2715 | 85 | } |
tonyp@2715 | 86 | |
tonyp@2715 | 87 | void G1AllocRegion::retire(bool fill_up) { |
tonyp@2715 | 88 | assert(_alloc_region != NULL, ar_ext_msg(this, "not initialized properly")); |
tonyp@2715 | 89 | |
tonyp@2715 | 90 | trace("retiring"); |
tonyp@2715 | 91 | HeapRegion* alloc_region = _alloc_region; |
tonyp@2715 | 92 | if (alloc_region != _dummy_region) { |
tonyp@2715 | 93 | // We never have to check whether the active region is empty or not, |
tonyp@2715 | 94 | // and potentially free it if it is, given that it's guaranteed that |
tonyp@2715 | 95 | // it will never be empty. |
tonyp@2715 | 96 | assert(!alloc_region->is_empty(), |
tonyp@2715 | 97 | ar_ext_msg(this, "the alloc region should never be empty")); |
tonyp@2715 | 98 | |
tonyp@2715 | 99 | if (fill_up) { |
tonyp@2715 | 100 | fill_up_remaining_space(alloc_region, _bot_updates); |
tonyp@2715 | 101 | } |
tonyp@2715 | 102 | |
tonyp@2715 | 103 | assert(alloc_region->used() >= _used_bytes_before, |
tonyp@2715 | 104 | ar_ext_msg(this, "invariant")); |
tonyp@2715 | 105 | size_t allocated_bytes = alloc_region->used() - _used_bytes_before; |
tonyp@2715 | 106 | retire_region(alloc_region, allocated_bytes); |
tonyp@2715 | 107 | _used_bytes_before = 0; |
tonyp@2715 | 108 | _alloc_region = _dummy_region; |
tonyp@2715 | 109 | } |
tonyp@2715 | 110 | trace("retired"); |
tonyp@2715 | 111 | } |
tonyp@2715 | 112 | |
tonyp@2715 | 113 | HeapWord* G1AllocRegion::new_alloc_region_and_allocate(size_t word_size, |
tonyp@2715 | 114 | bool force) { |
tonyp@2715 | 115 | assert(_alloc_region == _dummy_region, ar_ext_msg(this, "pre-condition")); |
tonyp@2715 | 116 | assert(_used_bytes_before == 0, ar_ext_msg(this, "pre-condition")); |
tonyp@2715 | 117 | |
tonyp@2715 | 118 | trace("attempting region allocation"); |
tonyp@2715 | 119 | HeapRegion* new_alloc_region = allocate_new_region(word_size, force); |
tonyp@2715 | 120 | if (new_alloc_region != NULL) { |
tonyp@2715 | 121 | new_alloc_region->reset_pre_dummy_top(); |
tonyp@2715 | 122 | // Need to do this before the allocation |
tonyp@2715 | 123 | _used_bytes_before = new_alloc_region->used(); |
tonyp@2715 | 124 | HeapWord* result = allocate(new_alloc_region, word_size, _bot_updates); |
tonyp@2715 | 125 | assert(result != NULL, ar_ext_msg(this, "the allocation should succeeded")); |
tonyp@2715 | 126 | |
tonyp@2715 | 127 | OrderAccess::storestore(); |
tonyp@2715 | 128 | // Note that we first perform the allocation and then we store the |
tonyp@2715 | 129 | // region in _alloc_region. This is the reason why an active region |
tonyp@2715 | 130 | // can never be empty. |
tonyp@2715 | 131 | _alloc_region = new_alloc_region; |
tonyp@2715 | 132 | trace("region allocation successful"); |
tonyp@2715 | 133 | return result; |
tonyp@2715 | 134 | } else { |
tonyp@2715 | 135 | trace("region allocation failed"); |
tonyp@2715 | 136 | return NULL; |
tonyp@2715 | 137 | } |
tonyp@2715 | 138 | ShouldNotReachHere(); |
tonyp@2715 | 139 | } |
tonyp@2715 | 140 | |
tonyp@2715 | 141 | void G1AllocRegion::fill_in_ext_msg(ar_ext_msg* msg, const char* message) { |
tonyp@2715 | 142 | msg->append("[%s] %s b: %s r: "PTR_FORMAT" u: "SIZE_FORMAT, |
tonyp@2715 | 143 | _name, message, BOOL_TO_STR(_bot_updates), |
tonyp@2715 | 144 | _alloc_region, _used_bytes_before); |
tonyp@2715 | 145 | } |
tonyp@2715 | 146 | |
tonyp@2715 | 147 | void G1AllocRegion::init() { |
tonyp@2715 | 148 | trace("initializing"); |
tonyp@2715 | 149 | assert(_alloc_region == NULL && _used_bytes_before == 0, |
tonyp@2715 | 150 | ar_ext_msg(this, "pre-condition")); |
tonyp@2715 | 151 | assert(_dummy_region != NULL, "should have been set"); |
tonyp@2715 | 152 | _alloc_region = _dummy_region; |
tonyp@2715 | 153 | trace("initialized"); |
tonyp@2715 | 154 | } |
tonyp@2715 | 155 | |
tonyp@2715 | 156 | HeapRegion* G1AllocRegion::release() { |
tonyp@2715 | 157 | trace("releasing"); |
tonyp@2715 | 158 | HeapRegion* alloc_region = _alloc_region; |
tonyp@2715 | 159 | retire(false /* fill_up */); |
tonyp@2715 | 160 | assert(_alloc_region == _dummy_region, "post-condition of retire()"); |
tonyp@2715 | 161 | _alloc_region = NULL; |
tonyp@2715 | 162 | trace("released"); |
tonyp@2715 | 163 | return (alloc_region == _dummy_region) ? NULL : alloc_region; |
tonyp@2715 | 164 | } |
tonyp@2715 | 165 | |
tonyp@2715 | 166 | #if G1_ALLOC_REGION_TRACING |
tonyp@2715 | 167 | void G1AllocRegion::trace(const char* str, size_t word_size, HeapWord* result) { |
tonyp@2715 | 168 | // All the calls to trace that set either just the size or the size |
tonyp@2715 | 169 | // and the result are considered part of level 2 tracing and are |
tonyp@2715 | 170 | // skipped during level 1 tracing. |
tonyp@2715 | 171 | if ((word_size == 0 && result == NULL) || (G1_ALLOC_REGION_TRACING > 1)) { |
tonyp@2715 | 172 | const size_t buffer_length = 128; |
tonyp@2715 | 173 | char hr_buffer[buffer_length]; |
tonyp@2715 | 174 | char rest_buffer[buffer_length]; |
tonyp@2715 | 175 | |
tonyp@2715 | 176 | HeapRegion* alloc_region = _alloc_region; |
tonyp@2715 | 177 | if (alloc_region == NULL) { |
tonyp@2715 | 178 | jio_snprintf(hr_buffer, buffer_length, "NULL"); |
tonyp@2715 | 179 | } else if (alloc_region == _dummy_region) { |
tonyp@2715 | 180 | jio_snprintf(hr_buffer, buffer_length, "DUMMY"); |
tonyp@2715 | 181 | } else { |
tonyp@2715 | 182 | jio_snprintf(hr_buffer, buffer_length, |
tonyp@2715 | 183 | HR_FORMAT, HR_FORMAT_PARAMS(alloc_region)); |
tonyp@2715 | 184 | } |
tonyp@2715 | 185 | |
tonyp@2715 | 186 | if (G1_ALLOC_REGION_TRACING > 1) { |
tonyp@2715 | 187 | if (result != NULL) { |
tonyp@2715 | 188 | jio_snprintf(rest_buffer, buffer_length, SIZE_FORMAT" "PTR_FORMAT, |
tonyp@2715 | 189 | word_size, result); |
tonyp@2715 | 190 | } else if (word_size != 0) { |
tonyp@2715 | 191 | jio_snprintf(rest_buffer, buffer_length, SIZE_FORMAT, word_size); |
tonyp@2715 | 192 | } else { |
tonyp@2715 | 193 | jio_snprintf(rest_buffer, buffer_length, ""); |
tonyp@2715 | 194 | } |
tonyp@2715 | 195 | } else { |
tonyp@2715 | 196 | jio_snprintf(rest_buffer, buffer_length, ""); |
tonyp@2715 | 197 | } |
tonyp@2715 | 198 | |
tonyp@2715 | 199 | tty->print_cr("[%s] %s : %s %s", _name, hr_buffer, str, rest_buffer); |
tonyp@2715 | 200 | } |
tonyp@2715 | 201 | } |
tonyp@2715 | 202 | #endif // G1_ALLOC_REGION_TRACING |
tonyp@2715 | 203 | |
tonyp@2715 | 204 | G1AllocRegion::G1AllocRegion(const char* name, |
tonyp@2715 | 205 | bool bot_updates) |
tonyp@2715 | 206 | : _name(name), _bot_updates(bot_updates), |
tonyp@2715 | 207 | _alloc_region(NULL), _used_bytes_before(0) { } |
tonyp@2715 | 208 |