src/share/vm/gc/g1/g1RemSet.cpp

rev 12936 : [mq]: 8xxxxxxx-rebuild-remembered-sets
rev 12939 : imported patch 8071280-specialize-heapregion-oops-on-card-seq-iterate
rev 12940 : imported patch 8071280-kim-review
rev 12942 : imported patch 8162928-micro-optimizations-in-remembered-set-scan
rev 12943 : imported patch 8162928-reviews
rev 12944 : imported patch 8177707-specialize-refine-card
rev 12945 : imported patch 8177707-review-kim-sangheon
rev 12946 : imported patch 8177044-remove-scan-top
rev 12947 : imported patch 8177044-kim-review

*** 733,742 ****
--- 733,743 ----
    // And find the region containing it.
    HeapRegion* r = _g1->heap_region_containing(start);
  
    HeapWord* scan_limit = _scan_state->scan_top(r->hrm_index());
    if (scan_limit <= start) {
+     // If the card starts above the area in the region containing objects to scan, skip it.
      return false;
    }
  
    // Okay to clean and process the card now.  There are still some
    // stale card cases that may be detected by iteration and dealt with