jdk8-mips64-public/hotspot: src/share/vm/gc_implementation/g1/g1BlockOffsetTable.inline.hpp@e7d0505c8a30 (annotated)

src/share/vm/gc_implementation/g1/g1BlockOffsetTable.inline.hpp@e7d0505c8a30 (annotated)

src/share/vm/gc_implementation/g1/g1BlockOffsetTable.inline.hpp

Fri, 10 Oct 2014 15:51:58 +0200

author: tschatzl
date: Fri, 10 Oct 2014 15:51:58 +0200
changeset 7257: e7d0505c8a30
parent 7256: 0fcaab91d485
child 7535: 7ae4e26cb1e0
child 9697: cfe3264deba4
permissions: -rw-r--r--

8059758: Footprint regressions with JDK-8038423
Summary: Changes in JDK-8038423 always initialize (zero out) virtual memory used for auxiliary data structures. This causes a footprint regression for G1 in startup benchmarks. This is because they do not touch that memory at all, so the operating system does not actually commit these pages. The fix is to, if the initialization value of the data structures matches the default value of just committed memory (=0), do not do anything.
Reviewed-by: jwilhelm, brutisso

 /*
  * Copyright (c) 2001, 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.
  *
  */
 #ifndef SHARE_VM_GC_IMPLEMENTATION_G1_G1BLOCKOFFSETTABLE_INLINE_HPP
 #define SHARE_VM_GC_IMPLEMENTATION_G1_G1BLOCKOFFSETTABLE_INLINE_HPP
 #include "gc_implementation/g1/g1BlockOffsetTable.hpp"
 #include "gc_implementation/g1/g1CollectedHeap.inline.hpp"
 #include "gc_implementation/g1/heapRegion.inline.hpp"
 #include "memory/space.hpp"
 inline HeapWord* G1BlockOffsetTable::block_start(const void* addr) {
   if (addr >= _bottom && addr < _end) {
     return block_start_unsafe(addr);
   } else {
     return NULL;
   }
 }
 inline HeapWord*
 G1BlockOffsetTable::block_start_const(const void* addr) const {
   if (addr >= _bottom && addr < _end) {
     return block_start_unsafe_const(addr);
   } else {
     return NULL;
   }
 }
 #define check_index(index, msg)                                                \
   assert((index) < (_reserved.word_size() >> LogN_words),                      \
          err_msg("%s - index: "SIZE_FORMAT", _vs.committed_size: "SIZE_FORMAT, \
                  msg, (index), (_reserved.word_size() >> LogN_words)));        \
   assert(G1CollectedHeap::heap()->is_in_exact(address_for_index_raw(index)),   \
          err_msg("Index "SIZE_FORMAT" corresponding to "PTR_FORMAT             \
                  " (%u) is not in committed area.",                            \
                  (index),                                                      \
                  p2i(address_for_index_raw(index)),                            \
                  G1CollectedHeap::heap()->addr_to_region(address_for_index_raw(index))));
 u_char G1BlockOffsetSharedArray::offset_array(size_t index) const {
   check_index(index, "index out of range");
   return _offset_array[index];
 }
 void G1BlockOffsetSharedArray::set_offset_array(size_t index, u_char offset) {
   check_index(index, "index out of range");
   set_offset_array_raw(index, offset);
 }
 void G1BlockOffsetSharedArray::set_offset_array(size_t index, HeapWord* high, HeapWord* low) {
   check_index(index, "index out of range");
   assert(high >= low, "addresses out of order");
   size_t offset = pointer_delta(high, low);
   check_offset(offset, "offset too large");
   set_offset_array(index, (u_char)offset);
 }
 void G1BlockOffsetSharedArray::set_offset_array(size_t left, size_t right, u_char offset) {
   check_index(right, "right index out of range");
   assert(left <= right, "indexes out of order");
   size_t num_cards = right - left + 1;
   if (UseMemSetInBOT) {
     memset(&_offset_array[left], offset, num_cards);
   } else {
     size_t i = left;
     const size_t end = i + num_cards;
     for (; i < end; i++) {
       _offset_array[i] = offset;
     }
   }
 }
 // Variant of index_for that does not check the index for validity.
 inline size_t G1BlockOffsetSharedArray::index_for_raw(const void* p) const {
   return pointer_delta((char*)p, _reserved.start(), sizeof(char)) >> LogN;
 }
 inline size_t G1BlockOffsetSharedArray::index_for(const void* p) const {
   char* pc = (char*)p;
   assert(pc >= (char*)_reserved.start() &&
          pc <  (char*)_reserved.end(),
          err_msg("p (" PTR_FORMAT ") not in reserved [" PTR_FORMAT ", " PTR_FORMAT ")",
                  p2i(p), p2i(_reserved.start()), p2i(_reserved.end())));
   size_t result = index_for_raw(p);
   check_index(result, "bad index from address");
   return result;
 }
 inline HeapWord*
 G1BlockOffsetSharedArray::address_for_index(size_t index) const {
   check_index(index, "index out of range");
   HeapWord* result = address_for_index_raw(index);
   assert(result >= _reserved.start() && result < _reserved.end(),
          err_msg("bad address from index result " PTR_FORMAT
                  " _reserved.start() " PTR_FORMAT " _reserved.end() "
                  PTR_FORMAT,
                  p2i(result), p2i(_reserved.start()), p2i(_reserved.end())));
   return result;
 }
 #undef check_index
 inline size_t
 G1BlockOffsetArray::block_size(const HeapWord* p) const {
   return gsp()->block_size(p);
 }
 inline HeapWord*
 G1BlockOffsetArray::block_at_or_preceding(const void* addr,
                                           bool has_max_index,
                                           size_t max_index) const {
   assert(_array->offset_array(0) == 0, "objects can't cross covered areas");
   size_t index = _array->index_for(addr);
   // We must make sure that the offset table entry we use is valid.  If
   // "addr" is past the end, start at the last known one and go forward.
   if (has_max_index) {
     index = MIN2(index, max_index);
   }
   HeapWord* q = _array->address_for_index(index);
   uint offset = _array->offset_array(index);  // Extend u_char to uint.
   while (offset >= N_words) {
     // The excess of the offset from N_words indicates a power of Base
     // to go back by.
     size_t n_cards_back = BlockOffsetArray::entry_to_cards_back(offset);
     q -= (N_words * n_cards_back);
     assert(q >= gsp()->bottom(), "Went below bottom!");
     index -= n_cards_back;
     offset = _array->offset_array(index);
   }
   assert(offset < N_words, "offset too large");
   q -= offset;
   return q;
 }
 inline HeapWord*
 G1BlockOffsetArray::
 forward_to_block_containing_addr_const(HeapWord* q, HeapWord* n,
                                        const void* addr) const {
   if (addr >= gsp()->top()) return gsp()->top();
   while (n <= addr) {
     q = n;
     oop obj = oop(q);
     if (obj->klass_or_null() == NULL) return q;
     n += block_size(q);
   }
   assert(q <= n, "wrong order for q and addr");
   assert(addr < n, "wrong order for addr and n");
   return q;
 }
 inline HeapWord*
 G1BlockOffsetArray::forward_to_block_containing_addr(HeapWord* q,
                                                      const void* addr) {
   if (oop(q)->klass_or_null() == NULL) return q;
   HeapWord* n = q + block_size(q);
   // In the normal case, where the query "addr" is a card boundary, and the
   // offset table chunks are the same size as cards, the block starting at
   // "q" will contain addr, so the test below will fail, and we'll fall
   // through quickly.
   if (n <= addr) {
     q = forward_to_block_containing_addr_slow(q, n, addr);
   }
   assert(q <= addr, "wrong order for current and arg");
   return q;
 }
 #endif // SHARE_VM_GC_IMPLEMENTATION_G1_G1BLOCKOFFSETTABLE_INLINE_HPP

Mercurial > jdk8-mips64-public > hotspot / annotate

src/share/vm/gc_implementation/g1/g1BlockOffsetTable.inline.hpp@e7d0505c8a30 (annotated)

src/share/vm/gc_implementation/g1/g1BlockOffsetTable.inline.hpp