8302709: Remove explicit remembered set verification in G1

Reviewed-by: ayang, iwalulya

Author: Thomas Schatzl

src/hotspot/share/gc/g1/g1CollectedHeap.cpp

@@ -2546,16 +2546,6 @@ void G1CollectedHeap::verify_region_attr_remset_is_tracked() {
 }
 #endif
 
-class VerifyRegionRemSetClosure : public HeapRegionClosure {
-  public:
-    bool do_heap_region(HeapRegion* hr) {
-      if (!hr->is_archive() && !hr->is_continues_humongous()) {
-        hr->verify_rem_set();
-      }
-      return false;
-    }
-};
-
 void G1CollectedHeap::start_new_collection_set() {
   collection_set()->start_incremental_building();
 
@@ -2587,11 +2577,6 @@ void G1CollectedHeap::verify_before_young_collection(G1HeapVerifier::G1VerifyTyp
   _verifier->prepare_for_verify();
   _verifier->verify_region_sets_optional();
   _verifier->verify_dirty_young_regions();
-  if (VerifyRememberedSets) {
-    log_info(gc, verify)("[Verifying RemSets before GC]");
-    VerifyRegionRemSetClosure v_cl;
-    heap_region_iterate(&v_cl);
-  }
   _verifier->verify_before_gc(type);
   verify_numa_regions("GC Start");
   phase_times()->record_verify_before_time_ms((Ticks::now() - start).seconds() * MILLIUNITS);
@@ -2602,11 +2587,6 @@ void G1CollectedHeap::verify_after_young_collection(G1HeapVerifier::G1VerifyType
     return;
   }
   Ticks start = Ticks::now();
-  if (VerifyRememberedSets) {
-    log_info(gc, verify)("[Verifying RemSets after GC]");
-    VerifyRegionRemSetClosure v_cl;
-    heap_region_iterate(&v_cl);
-  }
   _verifier->verify_after_gc(type);
   verify_numa_regions("GC End");
   _verifier->verify_region_sets_optional();

src/hotspot/share/gc/g1/heapRegion.cpp

@@ -629,45 +629,6 @@ void HeapRegion::verify(VerifyOption vo,
   verify_code_roots(vo, failures);
 }
 
-void HeapRegion::verify_rem_set(VerifyOption vo, bool* failures) const {
-  G1CollectedHeap* g1h = G1CollectedHeap::heap();
-  *failures = false;
-  HeapWord* p = bottom();
-  HeapWord* prev_p = NULL;
-  VerifyRemSetClosure vr_cl(g1h, vo);
-  while (p < top()) {
-    oop obj = cast_to_oop(p);
-    size_t obj_size = block_size(p);
-
-    if (!g1h->is_obj_dead_cond(obj, this, vo)) {
-      if (oopDesc::is_oop(obj)) {
-        vr_cl.set_containing_obj(obj);
-        obj->oop_iterate(&vr_cl);
-
-        if (vr_cl.has_failures()) {
-          *failures = true;
-        }
-        if (vr_cl.num_failures() >= G1MaxVerifyFailures) {
-          return;
-        }
-      } else {
-        log_error(gc, verify)(PTR_FORMAT " not an oop", p2i(obj));
-        *failures = true;
-        return;
-      }
-    }
-
-    prev_p = p;
-    p += obj_size;
-  }
-}
-
-void HeapRegion::verify_rem_set() const {
-  bool failures = false;
-  verify_rem_set(VerifyOption::G1UseConcMarking, &failures);
-  guarantee(!failures, "HeapRegion RemSet verification failed");
-}
-
 void HeapRegion::clear(bool mangle_space) {
   set_top(bottom());
 

src/hotspot/share/gc/g1/heapRegion.hpp

@@ -585,9 +585,6 @@ class HeapRegion : public CHeapObj<mtGC> {
   void print_on(outputStream* st) const;
 
   void verify(VerifyOption vo, bool* failures) const;
-
-  void verify_rem_set(VerifyOption vo, bool* failures) const;
-  void verify_rem_set() const;
 };
 
 // HeapRegionClosure is used for iterating over regions.