public boolean shouldLockOnCacheMiss(BlockType blockType) {
    if (blockType == null) {
      return true;
    }
    return shouldCacheBlockOnRead(blockType.getCategory());
  }
If we make sure the block could not be cached, we will not acquire the lock otherwise we will
acquire lock
hbase-server/src/main/java/org/apache/hadoop/hbase/io/hfile/CacheConfig.java