We will consider to use transferTo API to improve SCM's cach performace.
Discussion: 5th comment in HDFS-14355
Comment: FileMappableBlockLoader : Currently you are reading data from input stream and verifying checksum and writing that buffer to MBB. One thought here is: how about using FileChannel#transferTo API for transferring data from one channel to other natively. and then do mmap on destination file(assuming mmap may be faster in target file) and do checksum verification on it?