Set non blocking on /dev/rdma_cm

Alex Bowden alex.bowden at
Tue Aug 16 20:23:53 UTC 2016

Hi all,

I've modified rping to set O_NONBLOCKING on /dev/rdma_cm on the event channel (rdma_create_event_channel) which fails like this:

  9997 rping    CALL  openat(AT_FDCWD,0x800a42708,0x100002<O_RDWR|O_CLOEXEC>,<unused>0)
  9997 rping    NAMI  "/dev/rdma_cm"
  9997 rping    RET   openat 3

  9997 rping    CALL  fcntl(0x3,F_SETFL,0x6<O_RDWR|O_NONBLOCK>)
  9997 rping    RET   fcntl -1 errno 25 Inappropriate ioctl for device

Is this not supported for some reason? This is with the latest OFED v3.2 patches by Hans.

The manpage for rdma_create_event_channel seems to state you can set non-blocking on it.


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