[Simh] VAX Simulator 99.9% CPU , and flush nvram never finishes .

[Mark Pizzolato]

Hi James,

On Wednesday, May 23, 2018 at 7:03 PM, James W. Laferriere wrote:
> On Wed, 23 May 2018, Mark Pizzolato wrote:
> > On Wednesday, May 23, 2018 at 4:20 PM, James W. Laferriere wrote:
> >>  	Hello All ,  I am noticing a VERY High cpu with JUST simh running
> >> and it does not reduce over time .  Any ideas ?  Hopefully everything
> >> needed is below .
> ...snip...
> >
> > Hi James,
> >
> > Hmmm...
> >
> > First, please try the lastest GitHub code.
>  	Done ...
> 
> > Second, I see you've built the simulator with video support, but you're not
> using any Video device in your configuration.  Additionally, I see that you're
> working with the older SDL version 1 video.  SDL version 1 was needed when
> video capabilities were first added to simh, but at this point libSDL Version 2 is
> available on essentially all interesting host platforms, so libSDL1 is deprecated
> and some changes coming in the near future will remove any attempt to
> support it.
> > Try installing the libSDL Version 2 development package and rebuilding the
> simulator.
>  	I have downloaded and compliled up SDL2-2.0.8 ,  Tho not installed it
> for the above and below test .  But it will be soonest .
> 
> > Third, unless you're preparing to dig deeply under the covers, you probably
> want to run the optimized vs debug build of the simulator.
>  	Done .  The High CPU usage is now gone .  Though the never returning
> to command line prompt on 'exit' is still an issue .  I have to issue a ctrl-Z and
> then 'kill -HUP %1' to have the process stop .  Also fmi is there a way to get
> simh to flush output to the logfiles when it gets into such a state ?  Some signal
> or tool ?

Nothing special like this should be needed.  The hanging behavior you're seeing 
it broken and unexpected.  We'll fix that and no extra mechanism will be needed.

Please identify what your host OS is.  I can see it is some Linux version, but what distribution and version?  

Meanwhile, please provide the output produced when building the simulator, and the output of SHOW VERSION from the sim> prompt after you've made changes.

If the build is finding libSDL (version 1), then presumably it was installed by some 
OS package system.   Uninstall the libsdl-dev package and rebuild and run the 
simulator.

> > Let us know where this takes you.

- Mark