6716466: par compact - remove VerifyParallelOldWithMarkSweep code

Reviewed-by: jmasa

hotspot/src/share/vm/code/nmethod.cpp

@@ -1350,11 +1350,7 @@ bool nmethod::can_unload(BoolObjectClosure* is_alive,
       return false;
     }
   }
-  if (!UseParallelOldGC || !VerifyParallelOldWithMarkSweep) {
+  assert(unloading_occurred, "Inconsistency in unloading");
-    // Cannot do this test if verification of the UseParallelOldGC
-    // code using the PSMarkSweep code is being done.
-    assert(unloading_occurred, "Inconsistency in unloading");
-  }
   make_unloaded(is_alive, obj);
   return true;
 }

hotspot/src/share/vm/gc_implementation/parallelScavenge/parallelScavengeHeap.cpp

@@ -210,10 +210,6 @@ void ParallelScavengeHeap::post_initialize() {
   PSScavenge::initialize();
   if (UseParallelOldGC) {
     PSParallelCompact::post_initialize();
-    if (VerifyParallelOldWithMarkSweep) {
-      // Will be used for verification of par old.
-      PSMarkSweep::initialize();
-    }
   } else {
     PSMarkSweep::initialize();
   }

hotspot/src/share/vm/gc_implementation/parallelScavenge/psMarkSweep.cpp

@@ -35,9 +35,7 @@ void PSMarkSweep::initialize() {
   _ref_processor = new ReferenceProcessor(mr,
                                           true,    // atomic_discovery
                                           false);  // mt_discovery
-  if (!UseParallelOldGC || !VerifyParallelOldWithMarkSweep) {
+  _counters = new CollectorCounters("PSMarkSweep", 1);
-    _counters = new CollectorCounters("PSMarkSweep", 1);
-  }
 }
 
 // This method contains all heap specific policy for invoking mark sweep.
@@ -518,9 +516,6 @@ void PSMarkSweep::mark_sweep_phase1(bool clear_all_softrefs) {
   follow_stack();
 
   // Process reference objects found during marking
-
-  // Skipping the reference processing for VerifyParallelOldWithMarkSweep
-  // affects the marking (makes it different).
   {
     ReferencePolicy *soft_ref_policy;
     if (clear_all_softrefs) {

hotspot/src/share/vm/gc_implementation/parallelScavenge/psMarkSweepDecorator.cpp

@@ -152,20 +152,15 @@ void PSMarkSweepDecorator::precompact() {
         oop(q)->forward_to(oop(compact_top));
         assert(oop(q)->is_gc_marked(), "encoding the pointer should preserve the mark");
       } else {
-        // Don't clear the mark since it's confuses parallel old
+        // if the object isn't moving we can just set the mark to the default
-        // verification.
+        // mark and handle it specially later on.
-        if (!UseParallelOldGC || !VerifyParallelOldWithMarkSweep) {
+        oop(q)->init_mark();
-          // if the object isn't moving we can just set the mark to the default
-          // mark and handle it specially later on.
-          oop(q)->init_mark();
-        }
         assert(oop(q)->forwardee() == NULL, "should be forwarded to NULL");
       }
 
       // Update object start array
-      if (!UseParallelOldGC || !VerifyParallelOldWithMarkSweep) {
+      if (start_array) {
-        if (start_array)
+        start_array->allocate_block(compact_top);
-          start_array->allocate_block(compact_top);
       }
 
       VALIDATE_MARK_SWEEP_ONLY(MarkSweep::register_live_oop(oop(q), size));
@@ -219,19 +214,14 @@ void PSMarkSweepDecorator::precompact() {
             assert(oop(q)->is_gc_marked(), "encoding the pointer should preserve the mark");
           } else {
             // if the object isn't moving we can just set the mark to the default
-            // Don't clear the mark since it's confuses parallel old
+            // mark and handle it specially later on.
-            // verification.
+            oop(q)->init_mark();
-            if (!UseParallelOldGC || !VerifyParallelOldWithMarkSweep) {
-              // mark and handle it specially later on.
-              oop(q)->init_mark();
-            }
             assert(oop(q)->forwardee() == NULL, "should be forwarded to NULL");
           }
 
-          if (!UseParallelOldGC || !VerifyParallelOldWithMarkSweep) {
+          // Update object start array
-            // Update object start array
+          if (start_array) {
-            if (start_array)
+            start_array->allocate_block(compact_top);
-              start_array->allocate_block(compact_top);
           }
 
           VALIDATE_MARK_SWEEP_ONLY(MarkSweep::register_live_oop(oop(q), sz));

hotspot/src/share/vm/gc_implementation/parallelScavenge/psOldGen.cpp

@@ -152,9 +152,7 @@ void PSOldGen::precompact() {
   assert(heap->kind() == CollectedHeap::ParallelScavengeHeap, "Sanity");
 
   // Reset start array first.
-  debug_only(if (!UseParallelOldGC || !VerifyParallelOldWithMarkSweep) {)
   start_array()->reset();
-  debug_only(})
 
   object_mark_sweep()->precompact();
 

hotspot/src/share/vm/gc_implementation/parallelScavenge/psParallelCompact.cpp

@@ -100,93 +100,6 @@ GrowableArray<HeapWord*>* PSParallelCompact::_last_gc_live_oops_moved_to = NULL;
 GrowableArray<size_t>   * PSParallelCompact::_last_gc_live_oops_size = NULL;
 #endif
 
-// XXX beg - verification code; only works while we also mark in object headers
-static void
-verify_mark_bitmap(ParMarkBitMap& _mark_bitmap)
-{
-  ParallelScavengeHeap* heap = PSParallelCompact::gc_heap();
-
-  PSPermGen* perm_gen = heap->perm_gen();
-  PSOldGen* old_gen = heap->old_gen();
-  PSYoungGen* young_gen = heap->young_gen();
-
-  MutableSpace* perm_space = perm_gen->object_space();
-  MutableSpace* old_space = old_gen->object_space();
-  MutableSpace* eden_space = young_gen->eden_space();
-  MutableSpace* from_space = young_gen->from_space();
-  MutableSpace* to_space = young_gen->to_space();
-
-  // 'from_space' here is the survivor space at the lower address.
-  if (to_space->bottom() < from_space->bottom()) {
-    from_space = to_space;
-    to_space = young_gen->from_space();
-  }
-
-  HeapWord* boundaries[12];
-  unsigned int bidx = 0;
-  const unsigned int bidx_max = sizeof(boundaries) / sizeof(boundaries[0]);
-
-  boundaries[0] = perm_space->bottom();
-  boundaries[1] = perm_space->top();
-  boundaries[2] = old_space->bottom();
-  boundaries[3] = old_space->top();
-  boundaries[4] = eden_space->bottom();
-  boundaries[5] = eden_space->top();
-  boundaries[6] = from_space->bottom();
-  boundaries[7] = from_space->top();
-  boundaries[8] = to_space->bottom();
-  boundaries[9] = to_space->top();
-  boundaries[10] = to_space->end();
-  boundaries[11] = to_space->end();
-
-  BitMap::idx_t beg_bit = 0;
-  BitMap::idx_t end_bit;
-  BitMap::idx_t tmp_bit;
-  const BitMap::idx_t last_bit = _mark_bitmap.size();
-  do {
-    HeapWord* addr = _mark_bitmap.bit_to_addr(beg_bit);
-    if (_mark_bitmap.is_marked(beg_bit)) {
-      oop obj = (oop)addr;
-      assert(obj->is_gc_marked(), "obj header is not marked");
-      end_bit = _mark_bitmap.find_obj_end(beg_bit, last_bit);
-      const size_t size = _mark_bitmap.obj_size(beg_bit, end_bit);
-      assert(size == (size_t)obj->size(), "end bit wrong?");
-      beg_bit = _mark_bitmap.find_obj_beg(beg_bit + 1, last_bit);
-      assert(beg_bit > end_bit, "bit set in middle of an obj");
-    } else {
-      if (addr >= boundaries[bidx] && addr < boundaries[bidx + 1]) {
-        // a dead object in the current space.
-        oop obj = (oop)addr;
-        end_bit = _mark_bitmap.addr_to_bit(addr + obj->size());
-        assert(!obj->is_gc_marked(), "obj marked in header, not in bitmap");
-        tmp_bit = beg_bit + 1;
-        beg_bit = _mark_bitmap.find_obj_beg(tmp_bit, end_bit);
-        assert(beg_bit == end_bit, "beg bit set in unmarked obj");
-        beg_bit = _mark_bitmap.find_obj_end(tmp_bit, end_bit);
-        assert(beg_bit == end_bit, "end bit set in unmarked obj");
-      } else if (addr < boundaries[bidx + 2]) {
-        // addr is between top in the current space and bottom in the next.
-        end_bit = beg_bit + pointer_delta(boundaries[bidx + 2], addr);
-        tmp_bit = beg_bit;
-        beg_bit = _mark_bitmap.find_obj_beg(tmp_bit, end_bit);
-        assert(beg_bit == end_bit, "beg bit set above top");
-        beg_bit = _mark_bitmap.find_obj_end(tmp_bit, end_bit);
-        assert(beg_bit == end_bit, "end bit set above top");
-        bidx += 2;
-      } else if (bidx < bidx_max - 2) {
-        bidx += 2; // ???
-      } else {
-        tmp_bit = beg_bit;
-        beg_bit = _mark_bitmap.find_obj_beg(tmp_bit, last_bit);
-        assert(beg_bit == last_bit, "beg bit set outside heap");
-        beg_bit = _mark_bitmap.find_obj_end(tmp_bit, last_bit);
-        assert(beg_bit == last_bit, "end bit set outside heap");
-      }
-    }
-  } while (beg_bit < last_bit);
-}
-// XXX end - verification code; only works while we also mark in object headers
-
 #ifndef PRODUCT
 const char* PSParallelCompact::space_names[] = {
   "perm", "old ", "eden", "from", "to  "
@@ -1584,11 +1497,6 @@ void PSParallelCompact::summary_phase(ParCompactionManager* cm,
   // trace("2");
 
 #ifdef  ASSERT
-  if (VerifyParallelOldWithMarkSweep  &&
-      (PSParallelCompact::total_invocations() %
-         VerifyParallelOldWithMarkSweepInterval) == 0) {
-    verify_mark_bitmap(_mark_bitmap);
-  }
   if (TraceParallelOldGCMarkingPhase) {
     tty->print_cr("add_obj_count=" SIZE_FORMAT " "
                   "add_obj_bytes=" SIZE_FORMAT,
@@ -2038,39 +1946,9 @@ void PSParallelCompact::invoke_no_policy(bool maximum_heap_compaction) {
     }
 #endif  // #ifndef PRODUCT
 
-#ifdef ASSERT
-    if (VerifyParallelOldWithMarkSweep &&
-        (PSParallelCompact::total_invocations() %
-           VerifyParallelOldWithMarkSweepInterval) == 0) {
-      gclog_or_tty->print_cr("Verify marking with mark_sweep_phase1()");
-      if (PrintGCDetails && Verbose) {
-        gclog_or_tty->print_cr("mark_sweep_phase1:");
-      }
-      // Clear the discovered lists so that discovered objects
-      // don't look like they have been discovered twice.
-      ref_processor()->clear_discovered_references();
-
-      PSMarkSweep::allocate_stacks();
-      MemRegion mr = Universe::heap()->reserved_region();
-      PSMarkSweep::ref_processor()->enable_discovery();
-      PSMarkSweep::mark_sweep_phase1(maximum_heap_compaction);
-    }
-#endif
-
     bool max_on_system_gc = UseMaximumCompactionOnSystemGC && is_system_gc;
     summary_phase(vmthread_cm, maximum_heap_compaction || max_on_system_gc);
 
-#ifdef ASSERT
-    if (VerifyParallelOldWithMarkSweep &&
-        (PSParallelCompact::total_invocations() %
-           VerifyParallelOldWithMarkSweepInterval) == 0) {
-      if (PrintGCDetails && Verbose) {
-        gclog_or_tty->print_cr("mark_sweep_phase2:");
-      }
-      PSMarkSweep::mark_sweep_phase2();
-    }
-#endif
-
     COMPILER2_PRESENT(assert(DerivedPointerTable::is_active(), "Sanity"));
     COMPILER2_PRESENT(DerivedPointerTable::set_active(false));
 
@@ -2078,28 +1956,6 @@ void PSParallelCompact::invoke_no_policy(bool maximum_heap_compaction) {
     // needed by the compaction for filling holes in the dense prefix.
     adjust_roots();
 
-#ifdef ASSERT
-    if (VerifyParallelOldWithMarkSweep &&
-        (PSParallelCompact::total_invocations() %
-           VerifyParallelOldWithMarkSweepInterval) == 0) {
-      // Do a separate verify phase so that the verify
-      // code can use the the forwarding pointers to
-      // check the new pointer calculation.  The restore_marks()
-      // has to be done before the real compact.
-      vmthread_cm->set_action(ParCompactionManager::VerifyUpdate);
-      compact_perm(vmthread_cm);
-      compact_serial(vmthread_cm);
-      vmthread_cm->set_action(ParCompactionManager::ResetObjects);
-      compact_perm(vmthread_cm);
-      compact_serial(vmthread_cm);
-      vmthread_cm->set_action(ParCompactionManager::UpdateAndCopy);
-
-      // For debugging only
-      PSMarkSweep::restore_marks();
-      PSMarkSweep::deallocate_stacks();
-    }
-#endif
-
     compaction_start.update();
     // Does the perm gen always have to be done serially because
     // klasses are used in the update of an object?

hotspot/src/share/vm/gc_implementation/parallelScavenge/psPermGen.cpp

@@ -123,8 +123,6 @@ void PSPermGen::move_and_update(ParCompactionManager* cm) {
 
 void PSPermGen::precompact() {
   // Reset start array first.
-  debug_only(if (!UseParallelOldGC || !VerifyParallelOldWithMarkSweep) {)
   _start_array.reset();
-  debug_only(})
   object_mark_sweep()->precompact();
 }

hotspot/src/share/vm/gc_implementation/shared/markSweep.inline.hpp

@@ -23,13 +23,6 @@
  */
 
 inline void MarkSweep::mark_object(oop obj) {
-#ifndef SERIALGC
-  if (UseParallelOldGC && VerifyParallelOldWithMarkSweep) {
-    assert(PSParallelCompact::mark_bitmap()->is_marked(obj),
-           "Should be marked in the marking bitmap");
-  }
-#endif // SERIALGC
-
   // some marks may contain information we need to preserve so we store them away
   // and overwrite the mark.  We'll restore it at the end of markSweep.
   markOop mark = obj->mark();

hotspot/src/share/vm/runtime/globals.hpp

@@ -1189,13 +1189,6 @@ class CommandLineFlags {
   product(uintx, ParallelCMSThreads, 0,                                     \
           "Max number of threads CMS will use for concurrent work")         \
                                                                             \
-  develop(bool, VerifyParallelOldWithMarkSweep, false,                      \
-          "Use the MarkSweep code to verify phases of Parallel Old")        \
-                                                                            \
-  develop(uintx, VerifyParallelOldWithMarkSweepInterval, 1,                 \
-          "Interval at which the MarkSweep code is used to verify "         \
-          "phases of Parallel Old")                                         \
-                                                                            \
   develop(bool, ParallelOldMTUnsafeMarkBitMap, false,                       \
           "Use the Parallel Old MT unsafe in marking the bitmap")           \
                                                                             \