On 22 Mar 2012, at 15:09, Andrew Deason wrote: > On Thu, 22 Mar 2012 10:18:44 -0400 > chas williams - CONTRACTOR <[email protected]> wrote: > >> but besides this limit, there is also another determining factor in >> rx. rx, like tcp, negotiates a window of data to send before waiting >> for an ack from the other side which lets me data get sent. if the >> window doesnt grow large enough, then you will not be able to get the >> full bandwidth of the link. i believe usually, you hit the window >> size limit in rx before anything else though. >> >> there are some problems with using larger window sizes in rx related >> to queue management efficiency as i recall. > > But even without that, the window size still has a limit much smaller > than TCP.
That limit is imposed because it is the point at which the current RX implementation loses the queue efficiency/throughput tradeoff. You can run with a larger window size, but it will actually make things go slower. It was naively increasing the maximum window size to 255 that caused the huge performance problems in the 1.5.x series that Andrei highlighted at the 2010 European AFS workshop. S. _______________________________________________ OpenAFS-info mailing list [email protected] https://lists.openafs.org/mailman/listinfo/openafs-info
