[Users] Linux kernel: Crash of IB peer in RC mode is not detected

[Jack Wang]

Thanks Roland to clarify our confusion.

So looks ping-pong mechanism is the way to go.

Regards,
Jack

2014-10-23 20:43 GMT+02:00 Roland Dreier <roland at purestorage.com>:
> On Thu, Oct 23, 2014 at 6:50 AM, Jack Wang <xjtuwjp at gmail.com> wrote:
>>> I expected that RDMA-Write operations will fail if the other crashes.
>>> Also I hoped that an event is generated when a host is crashed. The subnet
>>> manager should notice it and notify every other device in the network.
>>>
>>> Are we missing something in our modules?
>>> Is there a way to determine that a RC peer crashed without implementing a
>>> ping-pong mechanism?
>
> If the remote system crashes then any memory regions, QPs, etc. are
> still valid with the remote HCA, and RDMA read/write operations will
> continue to succeed.  (Unless the system reboots and reinitializes the
> adapter or something like that).
>
> There isn't a way to detect a remote crash unless that remote crash
> disconnects your QP or otherwise affects the HCA on the crashed
> system.