dd-26638 [000] 22209.671242: funcgraph_entry:        4.161 us  |  lo_open();
   dd-26638 [000] 22209.671632: funcgraph_entry:  +    24.903 us  |  loop_queue_rq();
loop0-13110 [001] 22209.671764: funcgraph_entry:                  |  loop_queue_work() {
loop0-13110 [001] 22209.671781: funcgraph_entry:                  |    loop_handle_cmd() {
loop0-13110 [001] 22209.671782: funcgraph_entry:                  |      do_req_filebacked() {
loop0-13110 [001] 22209.671782: funcgraph_entry:  +    22.980 us  |        lo_read_simple();
loop0-13110 [001] 22209.671805: funcgraph_exit:   +    23.625 us  |      }
loop0-13110 [001] 22209.671811: funcgraph_exit:   +    29.815 us  |    }
loop0-13110 [001] 22209.671811: funcgraph_exit:   +    47.686 us  |  }
gmain-762   [000] 22209.671820: funcgraph_entry:  +    23.196 us  |  lo_complete_rq();
   dd-26638 [000] 22209.672127: funcgraph_entry:  # 18143.654 us  |  lo_release();