[Simh] Simh and OpenVMS Integrity V8.4 Network Support issues

[Mark Pizzolato - Info Comm]

On Saturday, March 31, 2012 at 9:32 AM, Maurizio De Tommaso wrote:
> Hi Mark,
> 
> I see you are able to reproduce the behavior of slowness of new SIMH code
> that I observed on my rx1620 Integrity server.
> 
> As by your suggestion, I modified my configuration file to include the
> directive "Set Noasync" and I removed the directive "set xq type=delqa".
> Now the new SIMH code runs with acceptable performance, similar to V3.8-1
> release. I turned on the debugging and I captured its output (see attached
> file), as per your instructions. During these tests I used EIB0 network adapter,
> Lat and Tcp/Ip protocols . As reported before, my impression is that the
> simulated network adapter is able to transmit but it is not able to receive
> packets.
> 
> I look forward for your updates

Hi Maurizio,

This turned out to be a simple missing /THREADS_ENABLE on the link line for the simulator.  Without that linker switch, all threads actually shared the single process and only one could run at a time.  The thread executing instructions eventually consumed enough CPU that the pthreads scheduler decided to finally run the disk I/O thread and do the disk I/O.  This is what caused the excessively slow behavior.

If you pull the latest code from the github master branch, things will work MUCH better.   
https://github.com/markpizz/simh/zipball/master

- Mark