Why do I see "io_setup failed" when running multipath -ll in Red Hat Enterprise Linux?

Issue

• multipath -ll output shows "io_setup failed" on one RHEL cluster node. Whenever multipath -ll command executed on one RHEL cluster node, I see first line says "Sep 11 00:46:02 | io_setup failed". Please review it and let me know your inputs.

# multipath -ll
Sep 11 00:46:02 | io_setup failed
mpath_dev (36000d3100036920000000000000001cd) dm-48 COMPELNT,Compellent Vol
size=40G features='1 queue_if_no_path' hwhandler='0' wp=rw
`-+- policy='round-robin 0' prio=1 status=active
  |- 8:0:1:40 sdag 66:0   active ready  running
  `- 7:0:3:40 sdbv 68:144 active ready  running

• Sometimes when running the command multipath -ll to display multipath maps and path statuses on a system that is configured to use the directio path checker, messages similar to the following appear:

$ multipath -ll
io_setup failed
io_setup failed
io_setup failed
io_setup failed
io_setup failed
io_setup failed
360a98000486e61396c344f4641434b50dm-19 NETAPP,LUN
[size=28G][features=1 queue_if_no_path][hwhandler=0]
\_ round-robin 0 [prio=0][active]
 \_ 4:0:0:0  sdbr 68:80   [active][faulty]
 \_ 3:0:0:0  sdb  8:16    [active][faulty]
\_ round-robin 0 [prio=0][enabled]
 \_ 3:0:1:0  sdaj 66:48   [active][faulty]
 \_ 4:0:1:0  sdcz 70:112  [active][faulty]