[openib-general] [PATCH/RFC 1/2] IB: Return "maybe_missed_event" hint from ib_req_notify_cq()

[Roland Dreier]

 > Sorry I was not intend to send previous email. Anyway I accidently sent it
 > out. What I thought was there would be a problem, if the missed_event
 > always return to 1. Then this napi poll would keep forever.

Well, it's limited by the quota that the net stack gives it, so
there's no possibility of looping forever.  However....

 > How about defer the rotting packets process later? like this:

that seems like it is still correct.

 > With this patch, I could get NAPI + non scaling code throughput performance
 > from 1XXMb/s to 7XXMb/s, anyway there are some other problems I am still
 > investigating now.

But I wonder why it gives you a factor of 4 in performance??  Why does
it make a difference?  I would have thought that the rotting packet
situation would be rare enough that it doesn't really matter for
performance exactly how we handle it.

What are the other problems you're investigating?

 - R.