[ofa-general] librdmacm - okay to select on a cm channel's file descriptor?

[Roland Dreier]

 > In an attempt to get unexpected DISCONNECT notifications during
 > ib communication, I'm trying to use 'select()' on the cm channel's file
 > descriptor, testing it for readability.  I've found that this works some of
 > the time, but not all of the time.

What happens when it doesn't work?  select() doesn't give you an event
but when you try to read there actually is an event there?

I took a quick look at the ucma kernel code and the implementation of
select() (the kernel uses poll() as the name but it all ends up in the
same code) looks straightforwardly correct -- there's only one place
where events are added to the queue for a file, and that place wakes up
the poll wait queue.  But maybe there is a funny bug somehow.

 - R.