On Wed, Nov 06, 2019 at 09:30:44PM -0800, tim Rowledge wrote:
> 
> 
> > On 2019-11-06, at 7:43 PM, Chris Muller <asqueaker at gmail.com> wrote:
> > There are two flavors of the Linux VM, you're using the version of the VM that's a little better, but requires you to install a file into your security limits that allows it to work.
> > 
> > Create a text file called "squeak.conf" with these contents (between the horizontal lines):
> > 
> > *       hard    rtprio  2
> > *       soft    rtprio  2
> 
> The daft thing is that this problem was purportedly fixed in linux kernels as of {mumble-mumble} years ago. Raspbian, for example, does not need it and Raspbian is based on a very conservative branch of Debian
> 

Uhmm... it's not a "problem" that needs to be fixed. The Rasbian
distribution of Debian Linux is typically intended as single-user
system on which you can safely assume that if the user does something
dumb, then it serves him/her right when the system locks up.

In the general case of a multi-user system, you don't want someone 
to elevate their thread priorities and accidentally lock up the
entire system. That's why you are not allowed to use real time
scheduling priority in ordinary user applications.

Some Linux distributions enforce this by default, and others do
not. I think that it more or less depends on the intended audience
for the distribution.

Dave