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

[Stephen Hoffman]

On Sat, 31 Mar 2012 18:31:33 +0200, Maurizio De Tommaso posited:

> I see you are able to reproduce the behavior of slowness of new SIMH code 
> that I observed on my rx1620 Integrity server.

Itanium alignment faults can trigger platform-specific performance issues.

Put another way, consider enabling the detection of and monitor for excessive numbers of alignment faults.  

OpenVMS I64 on Itanium requires the rough equivalent of ten to fifteen thousand instructions to fix a single alignment fault.  

A few alignment faults or more numerous faults in a non-performance-critical code-path aren't going to produce an application performance issue.  

Too many alignment faults or faults arising in a critical code-path, however, and application performance can degrade drastically.

An introduction to the topic, with links to more detailed articles: <http://labs.hoffmanlabs.com/node/160>