Bug#852192: using boot_delay=500 renders system unbootable

[積丹尼 Dan Jacobson <jidanni@jidanni.org>]

BH> The delay is applied after every line that is logged, whether or not
BH> it's displayed on the console.

OK maybe they should warn about that in
/usr/share/doc/linux-doc-4.9/Documentation/kernel-parameters.txt.gz

And add a new parameter that only applies to ones that are shown on the
console.

Hmmm, I always thought there were more lines sent to the console then
went in the logs (#852194).

Now I learn that there maybe instead less.

It is just a shame that there is no way to make sure without connecting
an external device.

Anyway I don't want to power cycle each time to test this.

Yup, not much the user can do to try to read them as they fly off the
screen.

No sure fire way to slow them down without also slowing down the many
more invisible ones... (but no way to tell without a high speed camera.)