Ludovic Courtès <ludo@gnu.org> writes:

> That sounds worrying.  Could you report it upstream?

I'll will.  After further investigation, it turns out that nouveau keeps
crashing in loop, which overwhelms the kernel.  Everything is extremely
unresponsive, I suppose because the kernel scheduler cannot allocate
much time to the user land processes.

This explains the power drain.

`dmesg' shows a sequence of [nouveau] errors in loop, but I haven't
managed to capture it so far because the system freezes too soon.

>> By the way, how do I make the above /sys/ tweak permanent on GuixSD?
>
> You could do something like:
>
>   (simple-service 'my-/sys-tweaks activation-service-type
>                   #~(call-with-output-file "/sys/…"
>                       (lambda (port)
>                         (display "1" port))))

I just tried your suggestion and it results in a kernel panic (on Linux
4.15).
I get a "No such file or directory" error.  I suppose that is because
the service is run too early.

> That said, we should probably build a higher-level
> ‘/sys-tweaks-service-type’ where we could directly pass pairs of file
> name/values.
>
> Would you like to give it a try?

Sure, whenever I have some more free time (in a week or so).

--
Pierre Neidhardt