long executeOp(int daemonId, int inputIdx, String ignore) throws IOException {
assert daemonId < numThreads : "Wrong daemonId.";
TinyDatanode dn = datanodes[daemonId];
long start = System.currentTimeMillis();
nameNode.blockReport(dn.dnRegistration, BlockListAsLongs.convertToArrayLongs(dn.blocks));
long end = System.currentTimeMillis();
return end - start;
}
