[HECnet] Trying to build SIMH from git (on OpenIndiana)

[Mark Pizzolato - Info Comm]

On Wednesday, March 13, 2013 at 11:51 AM, Cory Smelosky wrote:
Speaking of SIMH on Solaris and similar...is SIMH capable of SET CPU IDLE in
zones on SPARC?   It looks like 3.9-0 can't.

Well, I think I answered this yesterday on this list.   I'll restate what I wrote here:

Idling for any simulator requires that the host system's clock tick be <= the size of the simulated system's clock tick.   VAX systems have a clock tick of 10ms.   Idling for simulated VAX systems works best if the host clock tick is 1ms.

Windows systems have a user mode programmatically settable clock tick size (a facility useful for some media playback capabilities).   On Windows systems simh will set the host's clock tick to 1ms while a simulator is running.   

We haven't seen programmatically settable host clock tick sizes on other platforms.   In general, other platforms have a tick size which can be changed in some system specific way   (which might require building a kernel with a desired tick size) or not changeable at all.     This issue comes up often enough that adding how to make these system specific adjustments would be a useful addition to the simh FAQ.   Any feedback on this subject will be welcome.

Recent simh code will display what it has determined to be the host's clock size if simh believes the host's clock tick is too small to support idling when you attempt to enable idling. 

Recent simh code can always display host system's tick size with the 'EXAMINE TIMER OS_SLEEP_MIN_MS' command.

The latest simh code is available from https://github.com/simh/simh/archive/master.zip.

Gregg Levine wrote:
Idle on some items that are not Linux or FreeBSD or NetBSD may not 
work because of how they interpret the timer. Same goes for trying to 
get the idle function to work on Windows.

I haven't heard from anyone who's had issues getting idling to work on Windows.   If you know of such a case, I would be interested to explore what may be happening in this case.

Thanks.

- Mark Pizzolato