[openib-general] Re: FW: SDP problems with 64K page size

[Michael S. Tsirkin]

Quoting r. Roland Dreier <rolandd at cisco.com>:
> Subject: Re: FW: SDP problems with 64K page size
> 
>     Jerome> Just an open question: Do you think that we could get
>     Jerome> better performance if we would go with u32 instead of
>     Jerome> reducing the buffer to 16K?
> 
> Not sure.  One easy test you could try would be increasing 16384 to
> 32768 in my patch.

I would replace 16384 with 4096 instead, and see whether the performance
decreases. Other approaches need changing more places.

> If that works and improves performance, then
> further increases would probably be worthwhile also.

My worry would be sign extention kicking in at this point,
since we are doing math on these numbers.

> You could also try changing recv_size and send_size from u16 to s32 in
> the declaration in sdp_conn.h.

Some other places need cleaning up for this to work.

> BTW, I say all of this with only the vaguest understanding of the SDP
> code base, so it might be complete nonsense.
> 
>  - R.
> 

-- 
MST