Old laptop not able to get enough entropy in FreeBSD 11

[Bertram Scharpf]

On Friday, 25. Nov 2016, 20:06:55 -0800, Jack L. wrote:
> On Fri, Nov 25, 2016 at 7:32 PM, Bertram Scharpf <lists at bertram-scharpf.de>
> wrote:
> 
> > On Friday, 25. Nov 2016, 18:31:24 -0800, Jack L. wrote:
> > > >> > I have an old single core AMD Turion ML-37 laptop that has nothing
> > > >> > installed. When I boot it up, the moment it displays login:, it hangs
> > > >> > until i press some random keys. At shutdown, it will hang until I
> > > >> > press keys and it will not move onto the next line of shutdown until
> > > >> > I keep pressing keys.
> > > >> >
> > > >> > If I cat /dev/random > ./dev/null while using the laptop, it works
> > > >> > fine but when nothing is happening, the laptop hangs. Any ideas? It's
> > > >> > running 11.0-STABLE
> > > >
> > > > Any ideas on why the laptop would have that behavior in 11? It didn't hang
> > > > at all in 10.3-STABLE
> > > >
> > > I just installed 12-CURRENT on the laptop and it also hangs even at
> > > install/boot/shutdown until I hit keys, then it will move as long as I
> > > continue to hit keys. I also found that if I ping the laptop, it will
> > > respond but in between pings, it will hang. Using FreeBSD 10.3, it works
> > > perfectly fine without any random keypresses. Any ideas?
> >
> > I'm convinced this behaviour it worth being analysed.
> >
> > Can you gain any knowlegde by calling cat through truss?
> 
> How should I run that?

Sorry, that was probably too fast.

You could run one of those:

  # truss cat /dev/random >/dev/null
  # truss dd if=/dev/random of=/dev/null bs=512 count=3

But they will show just a series of read-write calls until a
read will hang. The detain presumably occurs in the random
device. That's kernel stuff. Does anybody have a hint how to
debug that without influencing the behaviour in question?

Bertram


-- 
Bertram Scharpf
Stuttgart, Deutschland/Germany
http://www.bertram-scharpf.de