[OpenAFS-devel] read performance 1.5.74 Linux

[Derrick Brashear]

On Tue, May 18, 2010 at 12:03 PM, Jeffrey Altman
<jaltman@secure-endpoints.com> wrote:
> On 5/18/2010 11:16 AM, Jeffrey Hutzelman wrote:
>> I'm concerned here that this might mean you are lying about window sizes=
.
>
> I (personally) am not lying about anything.

I think he meant that the software resulting from the assumptions wold
lie to (peers) about window size. Not the personal you.

Anyway,

>> =A0Dropping received data on
>> the floor when it was received within the advertised window is _not_
>> acceptable; that breaks flow control and exacerbates congestion.
>
> Of course it is but I believe that the early developers made a wise
> choice being causing a kernel panic and being inefficient on the wire.
> If you have to choose one, drop the data on the floor and let it be
> retransmitted.
>
> The goal is to ensure that we never get into this case which is why if
> the rxi_NeedMorePackets global variable is TRUE we must actually go and
> allocate more packets the next time it is safe to do so.
>
> The patch that was committed today does that for the first time in the
> history of Rx.

I'm not sure I believe that, but, certainly, it improves things from
where they were before. In any case, all of you seem to be talking
across each other.


--=20
Derrick