Tue, 26 Jan 2010 16:52:29 -0800
6920090: G1: Disable ReduceInitialCardMarks at least until 6920109 is fixed
Summary: G1 now answers "no" to the query can_elide_initializing_store_barrier() in the product build. A debug flag allows alternate behaviour in debug builds.
Reviewed-by: iveresov, tonyp
ysr@777 | 1 | /* |
xdono@1014 | 2 | * Copyright 2001-2009 Sun Microsystems, Inc. All Rights Reserved. |
ysr@777 | 3 | * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
ysr@777 | 4 | * |
ysr@777 | 5 | * This code is free software; you can redistribute it and/or modify it |
ysr@777 | 6 | * under the terms of the GNU General Public License version 2 only, as |
ysr@777 | 7 | * published by the Free Software Foundation. |
ysr@777 | 8 | * |
ysr@777 | 9 | * This code is distributed in the hope that it will be useful, but WITHOUT |
ysr@777 | 10 | * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
ysr@777 | 11 | * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
ysr@777 | 12 | * version 2 for more details (a copy is included in the LICENSE file that |
ysr@777 | 13 | * accompanied this code). |
ysr@777 | 14 | * |
ysr@777 | 15 | * You should have received a copy of the GNU General Public License version |
ysr@777 | 16 | * 2 along with this work; if not, write to the Free Software Foundation, |
ysr@777 | 17 | * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. |
ysr@777 | 18 | * |
ysr@777 | 19 | * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara, |
ysr@777 | 20 | * CA 95054 USA or visit www.sun.com if you need additional information or |
ysr@777 | 21 | * have any questions. |
ysr@777 | 22 | * |
ysr@777 | 23 | */ |
ysr@777 | 24 | |
ysr@777 | 25 | #include "incls/_precompiled.incl" |
ysr@777 | 26 | #include "incls/_heapRegionSeq.cpp.incl" |
ysr@777 | 27 | |
ysr@777 | 28 | // Local to this file. |
ysr@777 | 29 | |
ysr@777 | 30 | static int orderRegions(HeapRegion** hr1p, HeapRegion** hr2p) { |
ysr@777 | 31 | if ((*hr1p)->end() <= (*hr2p)->bottom()) return -1; |
ysr@777 | 32 | else if ((*hr2p)->end() <= (*hr1p)->bottom()) return 1; |
ysr@777 | 33 | else if (*hr1p == *hr2p) return 0; |
ysr@777 | 34 | else { |
ysr@777 | 35 | assert(false, "We should never compare distinct overlapping regions."); |
ysr@777 | 36 | } |
ysr@777 | 37 | return 0; |
ysr@777 | 38 | } |
ysr@777 | 39 | |
iveresov@828 | 40 | HeapRegionSeq::HeapRegionSeq(const size_t max_size) : |
ysr@777 | 41 | _alloc_search_start(0), |
ysr@777 | 42 | // The line below is the worst bit of C++ hackery I've ever written |
ysr@777 | 43 | // (Detlefs, 11/23). You should think of it as equivalent to |
ysr@777 | 44 | // "_regions(100, true)": initialize the growable array and inform it |
ysr@777 | 45 | // that it should allocate its elem array(s) on the C heap. The first |
ysr@777 | 46 | // argument, however, is actually a comma expression (new-expr, 100). |
ysr@777 | 47 | // The purpose of the new_expr is to inform the growable array that it |
ysr@777 | 48 | // is *already* allocated on the C heap: it uses the placement syntax to |
ysr@777 | 49 | // keep it from actually doing any allocation. |
ysr@777 | 50 | _regions((ResourceObj::operator new (sizeof(GrowableArray<HeapRegion*>), |
ysr@777 | 51 | (void*)&_regions, |
ysr@777 | 52 | ResourceObj::C_HEAP), |
iveresov@828 | 53 | (int)max_size), |
ysr@777 | 54 | true), |
ysr@777 | 55 | _next_rr_candidate(0), |
ysr@777 | 56 | _seq_bottom(NULL) |
ysr@777 | 57 | {} |
ysr@777 | 58 | |
ysr@777 | 59 | // Private methods. |
ysr@777 | 60 | |
ysr@777 | 61 | HeapWord* |
ysr@777 | 62 | HeapRegionSeq::alloc_obj_from_region_index(int ind, size_t word_size) { |
ysr@777 | 63 | assert(G1CollectedHeap::isHumongous(word_size), |
ysr@777 | 64 | "Allocation size should be humongous"); |
ysr@777 | 65 | int cur = ind; |
ysr@777 | 66 | int first = cur; |
ysr@777 | 67 | size_t sumSizes = 0; |
ysr@777 | 68 | while (cur < _regions.length() && sumSizes < word_size) { |
ysr@777 | 69 | // Loop invariant: |
ysr@777 | 70 | // For all i in [first, cur): |
ysr@777 | 71 | // _regions.at(i)->is_empty() |
ysr@777 | 72 | // && _regions.at(i) is contiguous with its predecessor, if any |
ysr@777 | 73 | // && sumSizes is the sum of the sizes of the regions in the interval |
ysr@777 | 74 | // [first, cur) |
ysr@777 | 75 | HeapRegion* curhr = _regions.at(cur); |
ysr@777 | 76 | if (curhr->is_empty() |
ysr@777 | 77 | && (first == cur |
ysr@777 | 78 | || (_regions.at(cur-1)->end() == |
ysr@777 | 79 | curhr->bottom()))) { |
ysr@777 | 80 | sumSizes += curhr->capacity() / HeapWordSize; |
ysr@777 | 81 | } else { |
ysr@777 | 82 | first = cur + 1; |
ysr@777 | 83 | sumSizes = 0; |
ysr@777 | 84 | } |
ysr@777 | 85 | cur++; |
ysr@777 | 86 | } |
ysr@777 | 87 | if (sumSizes >= word_size) { |
ysr@777 | 88 | _alloc_search_start = cur; |
ysr@777 | 89 | // Mark the allocated regions as allocated. |
ysr@777 | 90 | bool zf = G1CollectedHeap::heap()->allocs_are_zero_filled(); |
ysr@777 | 91 | HeapRegion* first_hr = _regions.at(first); |
ysr@777 | 92 | for (int i = first; i < cur; i++) { |
ysr@777 | 93 | HeapRegion* hr = _regions.at(i); |
ysr@777 | 94 | if (zf) |
ysr@777 | 95 | hr->ensure_zero_filled(); |
ysr@777 | 96 | { |
ysr@777 | 97 | MutexLockerEx x(ZF_mon, Mutex::_no_safepoint_check_flag); |
ysr@777 | 98 | hr->set_zero_fill_allocated(); |
ysr@777 | 99 | } |
ysr@777 | 100 | size_t sz = hr->capacity() / HeapWordSize; |
ysr@777 | 101 | HeapWord* tmp = hr->allocate(sz); |
ysr@777 | 102 | assert(tmp != NULL, "Humongous allocation failure"); |
ysr@777 | 103 | MemRegion mr = MemRegion(tmp, sz); |
jcoomes@916 | 104 | CollectedHeap::fill_with_object(mr); |
ysr@777 | 105 | hr->declare_filled_region_to_BOT(mr); |
ysr@777 | 106 | if (i == first) { |
ysr@777 | 107 | first_hr->set_startsHumongous(); |
ysr@777 | 108 | } else { |
ysr@777 | 109 | assert(i > first, "sanity"); |
ysr@777 | 110 | hr->set_continuesHumongous(first_hr); |
ysr@777 | 111 | } |
ysr@777 | 112 | } |
ysr@777 | 113 | HeapWord* first_hr_bot = first_hr->bottom(); |
ysr@777 | 114 | HeapWord* obj_end = first_hr_bot + word_size; |
ysr@777 | 115 | first_hr->set_top(obj_end); |
ysr@777 | 116 | return first_hr_bot; |
ysr@777 | 117 | } else { |
ysr@777 | 118 | // If we started from the beginning, we want to know why we can't alloc. |
ysr@777 | 119 | return NULL; |
ysr@777 | 120 | } |
ysr@777 | 121 | } |
ysr@777 | 122 | |
apetrusenko@1112 | 123 | void HeapRegionSeq::print_empty_runs() { |
ysr@777 | 124 | int empty_run = 0; |
ysr@777 | 125 | int n_empty = 0; |
ysr@777 | 126 | int empty_run_start; |
ysr@777 | 127 | for (int i = 0; i < _regions.length(); i++) { |
ysr@777 | 128 | HeapRegion* r = _regions.at(i); |
ysr@777 | 129 | if (r->continuesHumongous()) continue; |
apetrusenko@1112 | 130 | if (r->is_empty()) { |
ysr@777 | 131 | assert(!r->isHumongous(), "H regions should not be empty."); |
ysr@777 | 132 | if (empty_run == 0) empty_run_start = i; |
ysr@777 | 133 | empty_run++; |
ysr@777 | 134 | n_empty++; |
ysr@777 | 135 | } else { |
ysr@777 | 136 | if (empty_run > 0) { |
ysr@777 | 137 | gclog_or_tty->print(" %d:%d", empty_run_start, empty_run); |
ysr@777 | 138 | empty_run = 0; |
ysr@777 | 139 | } |
ysr@777 | 140 | } |
ysr@777 | 141 | } |
ysr@777 | 142 | if (empty_run > 0) { |
ysr@777 | 143 | gclog_or_tty->print(" %d:%d", empty_run_start, empty_run); |
ysr@777 | 144 | } |
ysr@777 | 145 | gclog_or_tty->print_cr(" [tot = %d]", n_empty); |
ysr@777 | 146 | } |
ysr@777 | 147 | |
ysr@777 | 148 | int HeapRegionSeq::find(HeapRegion* hr) { |
ysr@777 | 149 | // FIXME: optimized for adjacent regions of fixed size. |
ysr@777 | 150 | int ind = hr->hrs_index(); |
ysr@777 | 151 | if (ind != -1) { |
ysr@777 | 152 | assert(_regions.at(ind) == hr, "Mismatch"); |
ysr@777 | 153 | } |
ysr@777 | 154 | return ind; |
ysr@777 | 155 | } |
ysr@777 | 156 | |
ysr@777 | 157 | |
ysr@777 | 158 | // Public methods. |
ysr@777 | 159 | |
ysr@777 | 160 | void HeapRegionSeq::insert(HeapRegion* hr) { |
iveresov@828 | 161 | assert(!_regions.is_full(), "Too many elements in HeapRegionSeq"); |
ysr@777 | 162 | if (_regions.length() == 0 |
ysr@777 | 163 | || _regions.top()->end() <= hr->bottom()) { |
ysr@777 | 164 | hr->set_hrs_index(_regions.length()); |
ysr@777 | 165 | _regions.append(hr); |
ysr@777 | 166 | } else { |
ysr@777 | 167 | _regions.append(hr); |
ysr@777 | 168 | _regions.sort(orderRegions); |
ysr@777 | 169 | for (int i = 0; i < _regions.length(); i++) { |
ysr@777 | 170 | _regions.at(i)->set_hrs_index(i); |
ysr@777 | 171 | } |
ysr@777 | 172 | } |
ysr@777 | 173 | char* bot = (char*)_regions.at(0)->bottom(); |
ysr@777 | 174 | if (_seq_bottom == NULL || bot < _seq_bottom) _seq_bottom = bot; |
ysr@777 | 175 | } |
ysr@777 | 176 | |
ysr@777 | 177 | size_t HeapRegionSeq::length() { |
ysr@777 | 178 | return _regions.length(); |
ysr@777 | 179 | } |
ysr@777 | 180 | |
ysr@777 | 181 | size_t HeapRegionSeq::free_suffix() { |
ysr@777 | 182 | size_t res = 0; |
ysr@777 | 183 | int first = _regions.length() - 1; |
ysr@777 | 184 | int cur = first; |
ysr@777 | 185 | while (cur >= 0 && |
ysr@777 | 186 | (_regions.at(cur)->is_empty() |
ysr@777 | 187 | && (first == cur |
ysr@777 | 188 | || (_regions.at(cur+1)->bottom() == |
ysr@777 | 189 | _regions.at(cur)->end())))) { |
ysr@777 | 190 | res++; |
ysr@777 | 191 | cur--; |
ysr@777 | 192 | } |
ysr@777 | 193 | return res; |
ysr@777 | 194 | } |
ysr@777 | 195 | |
ysr@777 | 196 | HeapWord* HeapRegionSeq::obj_allocate(size_t word_size) { |
ysr@777 | 197 | int cur = _alloc_search_start; |
ysr@777 | 198 | // Make sure "cur" is a valid index. |
ysr@777 | 199 | assert(cur >= 0, "Invariant."); |
ysr@777 | 200 | HeapWord* res = alloc_obj_from_region_index(cur, word_size); |
ysr@777 | 201 | if (res == NULL) |
ysr@777 | 202 | res = alloc_obj_from_region_index(0, word_size); |
ysr@777 | 203 | return res; |
ysr@777 | 204 | } |
ysr@777 | 205 | |
ysr@777 | 206 | void HeapRegionSeq::iterate(HeapRegionClosure* blk) { |
ysr@777 | 207 | iterate_from((HeapRegion*)NULL, blk); |
ysr@777 | 208 | } |
ysr@777 | 209 | |
ysr@777 | 210 | // The first argument r is the heap region at which iteration begins. |
ysr@777 | 211 | // This operation runs fastest when r is NULL, or the heap region for |
ysr@777 | 212 | // which a HeapRegionClosure most recently returned true, or the |
ysr@777 | 213 | // heap region immediately to its right in the sequence. In all |
ysr@777 | 214 | // other cases a linear search is required to find the index of r. |
ysr@777 | 215 | |
ysr@777 | 216 | void HeapRegionSeq::iterate_from(HeapRegion* r, HeapRegionClosure* blk) { |
ysr@777 | 217 | |
ysr@777 | 218 | // :::: FIXME :::: |
ysr@777 | 219 | // Static cache value is bad, especially when we start doing parallel |
ysr@777 | 220 | // remembered set update. For now just don't cache anything (the |
ysr@777 | 221 | // code in the def'd out blocks). |
ysr@777 | 222 | |
ysr@777 | 223 | #if 0 |
ysr@777 | 224 | static int cached_j = 0; |
ysr@777 | 225 | #endif |
ysr@777 | 226 | int len = _regions.length(); |
ysr@777 | 227 | int j = 0; |
ysr@777 | 228 | // Find the index of r. |
ysr@777 | 229 | if (r != NULL) { |
ysr@777 | 230 | #if 0 |
ysr@777 | 231 | assert(cached_j >= 0, "Invariant."); |
ysr@777 | 232 | if ((cached_j < len) && (r == _regions.at(cached_j))) { |
ysr@777 | 233 | j = cached_j; |
ysr@777 | 234 | } else if ((cached_j + 1 < len) && (r == _regions.at(cached_j + 1))) { |
ysr@777 | 235 | j = cached_j + 1; |
ysr@777 | 236 | } else { |
ysr@777 | 237 | j = find(r); |
ysr@777 | 238 | #endif |
ysr@777 | 239 | if (j < 0) { |
ysr@777 | 240 | j = 0; |
ysr@777 | 241 | } |
ysr@777 | 242 | #if 0 |
ysr@777 | 243 | } |
ysr@777 | 244 | #endif |
ysr@777 | 245 | } |
ysr@777 | 246 | int i; |
ysr@777 | 247 | for (i = j; i < len; i += 1) { |
ysr@777 | 248 | int res = blk->doHeapRegion(_regions.at(i)); |
ysr@777 | 249 | if (res) { |
ysr@777 | 250 | #if 0 |
ysr@777 | 251 | cached_j = i; |
ysr@777 | 252 | #endif |
ysr@777 | 253 | blk->incomplete(); |
ysr@777 | 254 | return; |
ysr@777 | 255 | } |
ysr@777 | 256 | } |
ysr@777 | 257 | for (i = 0; i < j; i += 1) { |
ysr@777 | 258 | int res = blk->doHeapRegion(_regions.at(i)); |
ysr@777 | 259 | if (res) { |
ysr@777 | 260 | #if 0 |
ysr@777 | 261 | cached_j = i; |
ysr@777 | 262 | #endif |
ysr@777 | 263 | blk->incomplete(); |
ysr@777 | 264 | return; |
ysr@777 | 265 | } |
ysr@777 | 266 | } |
ysr@777 | 267 | } |
ysr@777 | 268 | |
ysr@777 | 269 | void HeapRegionSeq::iterate_from(int idx, HeapRegionClosure* blk) { |
ysr@777 | 270 | int len = _regions.length(); |
ysr@777 | 271 | int i; |
ysr@777 | 272 | for (i = idx; i < len; i++) { |
ysr@777 | 273 | if (blk->doHeapRegion(_regions.at(i))) { |
ysr@777 | 274 | blk->incomplete(); |
ysr@777 | 275 | return; |
ysr@777 | 276 | } |
ysr@777 | 277 | } |
ysr@777 | 278 | for (i = 0; i < idx; i++) { |
ysr@777 | 279 | if (blk->doHeapRegion(_regions.at(i))) { |
ysr@777 | 280 | blk->incomplete(); |
ysr@777 | 281 | return; |
ysr@777 | 282 | } |
ysr@777 | 283 | } |
ysr@777 | 284 | } |
ysr@777 | 285 | |
ysr@777 | 286 | MemRegion HeapRegionSeq::shrink_by(size_t shrink_bytes, |
ysr@777 | 287 | size_t& num_regions_deleted) { |
ysr@777 | 288 | assert(shrink_bytes % os::vm_page_size() == 0, "unaligned"); |
ysr@777 | 289 | assert(shrink_bytes % HeapRegion::GrainBytes == 0, "unaligned"); |
ysr@777 | 290 | |
ysr@777 | 291 | if (_regions.length() == 0) { |
ysr@777 | 292 | num_regions_deleted = 0; |
ysr@777 | 293 | return MemRegion(); |
ysr@777 | 294 | } |
ysr@777 | 295 | int j = _regions.length() - 1; |
ysr@777 | 296 | HeapWord* end = _regions.at(j)->end(); |
ysr@777 | 297 | HeapWord* last_start = end; |
ysr@777 | 298 | while (j >= 0 && shrink_bytes > 0) { |
ysr@777 | 299 | HeapRegion* cur = _regions.at(j); |
ysr@777 | 300 | // We have to leave humongous regions where they are, |
ysr@777 | 301 | // and work around them. |
ysr@777 | 302 | if (cur->isHumongous()) { |
ysr@777 | 303 | return MemRegion(last_start, end); |
ysr@777 | 304 | } |
ysr@777 | 305 | assert(cur == _regions.top(), "Should be top"); |
ysr@777 | 306 | if (!cur->is_empty()) break; |
ysr@1395 | 307 | cur->reset_zero_fill(); |
ysr@777 | 308 | shrink_bytes -= cur->capacity(); |
ysr@777 | 309 | num_regions_deleted++; |
ysr@777 | 310 | _regions.pop(); |
ysr@777 | 311 | last_start = cur->bottom(); |
ysr@777 | 312 | // We need to delete these somehow, but can't currently do so here: if |
ysr@777 | 313 | // we do, the ZF thread may still access the deleted region. We'll |
ysr@777 | 314 | // leave this here as a reminder that we have to do something about |
ysr@777 | 315 | // this. |
ysr@777 | 316 | // delete cur; |
ysr@777 | 317 | j--; |
ysr@777 | 318 | } |
ysr@777 | 319 | return MemRegion(last_start, end); |
ysr@777 | 320 | } |
ysr@777 | 321 | |
ysr@777 | 322 | |
ysr@777 | 323 | class PrintHeapRegionClosure : public HeapRegionClosure { |
ysr@777 | 324 | public: |
ysr@777 | 325 | bool doHeapRegion(HeapRegion* r) { |
ysr@777 | 326 | gclog_or_tty->print(PTR_FORMAT ":", r); |
ysr@777 | 327 | r->print(); |
ysr@777 | 328 | return false; |
ysr@777 | 329 | } |
ysr@777 | 330 | }; |
ysr@777 | 331 | |
ysr@777 | 332 | void HeapRegionSeq::print() { |
ysr@777 | 333 | PrintHeapRegionClosure cl; |
ysr@777 | 334 | iterate(&cl); |
ysr@777 | 335 | } |