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

[Shirley Ma]

> I would really like to understand why ehca does worse with NAPI.  In
> my tests both mthca and ipath exhibit various degrees of improvement
> depending on the test -- but I've never seen performance get worse.
> This is the main thing holding back merging NAPI.
>
> Does the NAPI patch help mthca on pSeries?  I wonder if it's not ehca,
> but rather that there's some ppc64 quirk that makes NAPI a lot more
> expensive.
>
>  - R.

Got your point. Sorry I haven't made any big progress yet. What I have
found so far in none scaling code, if I always set missed_event = 0 without
peeking rotting packet, then NAPI will increase the performance and reduce
the cpu utilization. That's the reason I suggest above change.
I have't found the reason for scaling code dropping 2/3 of the performance
yet.
The NAPI touch test for methca on power performance is good.
So I don't think it's ppc4 issue.

Thanks
Shirley
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