jdk8-mips64-public/hotspot: src/share/vm/gc_implementation/g1/g1ParScanThreadState.cpp@7df07d855c8e (annotated)

src/share/vm/gc_implementation/g1/g1ParScanThreadState.cpp@7df07d855c8e (annotated)

src/share/vm/gc_implementation/g1/g1ParScanThreadState.cpp

Mon, 21 Jul 2014 09:59:46 +0200

author: tschatzl
date: Mon, 21 Jul 2014 09:59:46 +0200
changeset 7007: 7df07d855c8e
parent 6939: cd43876f692e
child 7031: ee019285a52c
permissions: -rw-r--r--

8048085: Aborting marking just before remark results in useless additional clearing of the next mark bitmap
Summary: Skip clearing the next bitmap if we just recently aborted since the full GC already clears this bitmap.
Reviewed-by: brutisso

 /*
  * Copyright (c) 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/g1/g1CollectedHeap.inline.hpp"
 #include "gc_implementation/g1/g1OopClosures.inline.hpp"
 #include "gc_implementation/g1/g1ParScanThreadState.inline.hpp"
 #include "oops/oop.inline.hpp"
 #include "oops/oop.pcgc.inline.hpp"
 #include "runtime/prefetch.inline.hpp"
 G1ParScanThreadState::G1ParScanThreadState(G1CollectedHeap* g1h, uint queue_num, ReferenceProcessor* rp)
   : _g1h(g1h),
     _refs(g1h->task_queue(queue_num)),
     _dcq(&g1h->dirty_card_queue_set()),
     _ct_bs(g1h->g1_barrier_set()),
     _g1_rem(g1h->g1_rem_set()),
     _hash_seed(17), _queue_num(queue_num),
     _term_attempts(0),
     _surviving_alloc_buffer(g1h->desired_plab_sz(GCAllocForSurvived)),
     _tenured_alloc_buffer(g1h->desired_plab_sz(GCAllocForTenured)),
     _age_table(false), _scanner(g1h, rp),
     _strong_roots_time(0), _term_time(0),
     _alloc_buffer_waste(0), _undo_waste(0) {
   _scanner.set_par_scan_thread_state(this);
   // we allocate G1YoungSurvRateNumRegions plus one entries, since
   // we "sacrifice" entry 0 to keep track of surviving bytes for
   // non-young regions (where the age is -1)
   // We also add a few elements at the beginning and at the end in
   // an attempt to eliminate cache contention
   uint real_length = 1 + _g1h->g1_policy()->young_cset_region_length();
   uint array_length = PADDING_ELEM_NUM +
                       real_length +
                       PADDING_ELEM_NUM;
   _surviving_young_words_base = NEW_C_HEAP_ARRAY(size_t, array_length, mtGC);
   if (_surviving_young_words_base == NULL)
     vm_exit_out_of_memory(array_length * sizeof(size_t), OOM_MALLOC_ERROR,
                           "Not enough space for young surv histo.");
   _surviving_young_words = _surviving_young_words_base + PADDING_ELEM_NUM;
   memset(_surviving_young_words, 0, (size_t) real_length * sizeof(size_t));
   _alloc_buffers[GCAllocForSurvived] = &_surviving_alloc_buffer;
   _alloc_buffers[GCAllocForTenured]  = &_tenured_alloc_buffer;
   _start = os::elapsedTime();
 }
 G1ParScanThreadState::~G1ParScanThreadState() {
   retire_alloc_buffers();
   FREE_C_HEAP_ARRAY(size_t, _surviving_young_words_base, mtGC);
 }
 void
 G1ParScanThreadState::print_termination_stats_hdr(outputStream* const st)
 {
   st->print_raw_cr("GC Termination Stats");
   st->print_raw_cr("     elapsed  --strong roots-- -------termination-------"
                    " ------waste (KiB)------");
   st->print_raw_cr("thr     ms        ms      %        ms      %    attempts"
                    "  total   alloc    undo");
   st->print_raw_cr("--- --------- --------- ------ --------- ------ --------"
                    " ------- ------- -------");
 }
 void
 G1ParScanThreadState::print_termination_stats(int i,
                                               outputStream* const st) const
 {
   const double elapsed_ms = elapsed_time() * 1000.0;
   const double s_roots_ms = strong_roots_time() * 1000.0;
   const double term_ms    = term_time() * 1000.0;
   st->print_cr("%3d %9.2f %9.2f %6.2f "
                "%9.2f %6.2f " SIZE_FORMAT_W(8) " "
                SIZE_FORMAT_W(7) " " SIZE_FORMAT_W(7) " " SIZE_FORMAT_W(7),
                i, elapsed_ms, s_roots_ms, s_roots_ms * 100 / elapsed_ms,
                term_ms, term_ms * 100 / elapsed_ms, term_attempts(),
                (alloc_buffer_waste() + undo_waste()) * HeapWordSize / K,
                alloc_buffer_waste() * HeapWordSize / K,
                undo_waste() * HeapWordSize / K);
 }
 #ifdef ASSERT
 bool G1ParScanThreadState::verify_ref(narrowOop* ref) const {
   assert(ref != NULL, "invariant");
   assert(UseCompressedOops, "sanity");
   assert(!has_partial_array_mask(ref), err_msg("ref=" PTR_FORMAT, p2i(ref)));
   oop p = oopDesc::load_decode_heap_oop(ref);
   assert(_g1h->is_in_g1_reserved(p),
          err_msg("ref=" PTR_FORMAT " p=" PTR_FORMAT, p2i(ref), p2i(p)));
   return true;
 }
 bool G1ParScanThreadState::verify_ref(oop* ref) const {
   assert(ref != NULL, "invariant");
   if (has_partial_array_mask(ref)) {
     // Must be in the collection set--it's already been copied.
     oop p = clear_partial_array_mask(ref);
     assert(_g1h->obj_in_cs(p),
            err_msg("ref=" PTR_FORMAT " p=" PTR_FORMAT, p2i(ref), p2i(p)));
   } else {
     oop p = oopDesc::load_decode_heap_oop(ref);
     assert(_g1h->is_in_g1_reserved(p),
            err_msg("ref=" PTR_FORMAT " p=" PTR_FORMAT, p2i(ref), p2i(p)));
   }
   return true;
 }
 bool G1ParScanThreadState::verify_task(StarTask ref) const {
   if (ref.is_narrow()) {
     return verify_ref((narrowOop*) ref);
   } else {
     return verify_ref((oop*) ref);
   }
 }
 #endif // ASSERT
 void G1ParScanThreadState::trim_queue() {
   assert(_evac_failure_cl != NULL, "not set");
   StarTask ref;
   do {
     // Drain the overflow stack first, so other threads can steal.
     while (_refs->pop_overflow(ref)) {
       dispatch_reference(ref);
     }
     while (_refs->pop_local(ref)) {
       dispatch_reference(ref);
     }
   } while (!_refs->is_empty());
 }
 oop G1ParScanThreadState::copy_to_survivor_space(oop const old) {
   size_t word_sz = old->size();
   HeapRegion* from_region = _g1h->heap_region_containing_raw(old);
   // +1 to make the -1 indexes valid...
   int       young_index = from_region->young_index_in_cset()+1;
   assert( (from_region->is_young() && young_index >  0) ||
          (!from_region->is_young() && young_index == 0), "invariant" );
   G1CollectorPolicy* g1p = _g1h->g1_policy();
   markOop m = old->mark();
   int age = m->has_displaced_mark_helper() ? m->displaced_mark_helper()->age()
                                            : m->age();
   GCAllocPurpose alloc_purpose = g1p->evacuation_destination(from_region, age,
                                                              word_sz);
   HeapWord* obj_ptr = allocate(alloc_purpose, word_sz);
 #ifndef PRODUCT
   // Should this evacuation fail?
   if (_g1h->evacuation_should_fail()) {
     if (obj_ptr != NULL) {
       undo_allocation(alloc_purpose, obj_ptr, word_sz);
       obj_ptr = NULL;
     }
   }
 #endif // !PRODUCT
   if (obj_ptr == NULL) {
     // This will either forward-to-self, or detect that someone else has
     // installed a forwarding pointer.
     return _g1h->handle_evacuation_failure_par(this, old);
   }
   oop obj = oop(obj_ptr);
   // We're going to allocate linearly, so might as well prefetch ahead.
   Prefetch::write(obj_ptr, PrefetchCopyIntervalInBytes);
   oop forward_ptr = old->forward_to_atomic(obj);
   if (forward_ptr == NULL) {
     Copy::aligned_disjoint_words((HeapWord*) old, obj_ptr, word_sz);
     // alloc_purpose is just a hint to allocate() above, recheck the type of region
     // we actually allocated from and update alloc_purpose accordingly
     HeapRegion* to_region = _g1h->heap_region_containing_raw(obj_ptr);
     alloc_purpose = to_region->is_young() ? GCAllocForSurvived : GCAllocForTenured;
     if (g1p->track_object_age(alloc_purpose)) {
       // We could simply do obj->incr_age(). However, this causes a
       // performance issue. obj->incr_age() will first check whether
       // the object has a displaced mark by checking its mark word;
       // getting the mark word from the new location of the object
       // stalls. So, given that we already have the mark word and we
       // are about to install it anyway, it's better to increase the
       // age on the mark word, when the object does not have a
       // displaced mark word. We're not expecting many objects to have
       // a displaced marked word, so that case is not optimized
       // further (it could be...) and we simply call obj->incr_age().
       if (m->has_displaced_mark_helper()) {
         // in this case, we have to install the mark word first,
         // otherwise obj looks to be forwarded (the old mark word,
         // which contains the forward pointer, was copied)
         obj->set_mark(m);
         obj->incr_age();
       } else {
         m = m->incr_age();
         obj->set_mark(m);
       }
       age_table()->add(obj, word_sz);
     } else {
       obj->set_mark(m);
     }
     if (G1StringDedup::is_enabled()) {
       G1StringDedup::enqueue_from_evacuation(from_region->is_young(),
                                              to_region->is_young(),
                                              queue_num(),
                                              obj);
     }
     size_t* surv_young_words = surviving_young_words();
     surv_young_words[young_index] += word_sz;
     if (obj->is_objArray() && arrayOop(obj)->length() >= ParGCArrayScanChunk) {
       // We keep track of the next start index in the length field of
       // the to-space object. The actual length can be found in the
       // length field of the from-space object.
       arrayOop(obj)->set_length(0);
       oop* old_p = set_partial_array_mask(old);
       push_on_queue(old_p);
     } else {
       // No point in using the slower heap_region_containing() method,
       // given that we know obj is in the heap.
       _scanner.set_region(_g1h->heap_region_containing_raw(obj));
       obj->oop_iterate_backwards(&_scanner);
     }
   } else {
     undo_allocation(alloc_purpose, obj_ptr, word_sz);
     obj = forward_ptr;
   }
   return obj;
 }
 HeapWord* G1ParScanThreadState::allocate_slow(GCAllocPurpose purpose, size_t word_sz) {
   HeapWord* obj = NULL;
   size_t gclab_word_size = _g1h->desired_plab_sz(purpose);
   if (word_sz * 100 < gclab_word_size * ParallelGCBufferWastePct) {
     G1ParGCAllocBuffer* alloc_buf = alloc_buffer(purpose);
     add_to_alloc_buffer_waste(alloc_buf->words_remaining());
     alloc_buf->retire(false /* end_of_gc */, false /* retain */);
     HeapWord* buf = _g1h->par_allocate_during_gc(purpose, gclab_word_size);
     if (buf == NULL) {
       return NULL; // Let caller handle allocation failure.
     }
     // Otherwise.
     alloc_buf->set_word_size(gclab_word_size);
     alloc_buf->set_buf(buf);
     obj = alloc_buf->allocate(word_sz);
     assert(obj != NULL, "buffer was definitely big enough...");
   } else {
     obj = _g1h->par_allocate_during_gc(purpose, word_sz);
   }
   return obj;
 }
 void G1ParScanThreadState::undo_allocation(GCAllocPurpose purpose, HeapWord* obj, size_t word_sz) {
   if (alloc_buffer(purpose)->contains(obj)) {
     assert(alloc_buffer(purpose)->contains(obj + word_sz - 1),
            "should contain whole object");
     alloc_buffer(purpose)->undo_allocation(obj, word_sz);
   } else {
     CollectedHeap::fill_with_object(obj, word_sz);
     add_to_undo_waste(word_sz);
   }
 }
 HeapWord* G1ParScanThreadState::allocate(GCAllocPurpose purpose, size_t word_sz) {
   HeapWord* obj = alloc_buffer(purpose)->allocate(word_sz);
   if (obj != NULL) {
     return obj;
   }
   return allocate_slow(purpose, word_sz);
 }
 void G1ParScanThreadState::retire_alloc_buffers() {
   for (int ap = 0; ap < GCAllocPurposeCount; ++ap) {
     size_t waste = _alloc_buffers[ap]->words_remaining();
     add_to_alloc_buffer_waste(waste);
     _alloc_buffers[ap]->flush_stats_and_retire(_g1h->stats_for_purpose((GCAllocPurpose)ap),
                                                true /* end_of_gc */,
                                                false /* retain */);
   }
 }

Mercurial > jdk8-mips64-public > hotspot / annotate

src/share/vm/gc_implementation/g1/g1ParScanThreadState.cpp@7df07d855c8e (annotated)

src/share/vm/gc_implementation/g1/g1ParScanThreadState.cpp