Re: Boot time and 3 sec in warning_print

[Julien Grall <julien@xxxxxxx>]

Hi Andrew,

On 15/02/2021 15:00, Andrew Cooper wrote:
> On 15/02/2021 10:41, Jan Beulich wrote:
> > On 15.02.2021 11:35, Julien Grall wrote:
> > > On 15/02/2021 08:38, Jan Beulich wrote:
> > > > On 15.02.2021 09:13, Jürgen Groß wrote:
> > > What was just an "annoyance" for boot can now completely wreck your
> > > guests and system (not many software can tolerate large downtime).
> > >
> > > So I think we either want to drop the 3s pause completely or allow the
> > > user to decide whether he/she cares about it via a command line option.
> > >
> > > I am leaning towards the former at the moment.
> > I'm afraid I'm -2 towards complete removal. I'm at least -1 towards
> > shortening of the pause, as already indicated.
> A 3s delay on boot doesn't even cause most people to notice.  The
> infrastructure has failed at its intended purpose.
>
> Therefore, we should consider now to replace this largely-failed
> experiment with something better.
>
>
> Personally, I think ARM is abusing this in the first place.  Adding a 3
> second delay for someone who's explicitly chosen hmp_unsafe is petty.
For Arm, the original goal was to get all the important warning in a 
single place so they are easy to find.
The 3 seconds is unfortunately an unintended consequence of using 
warning_add().
> So is adding a 3 second delay for anyone who's explicitly chosen a
> non-default configuration.  In retrospect, I think the delay for hvm_fep
> is also wrong, especially as we also have a taint for it. >
>
> The *only* way to make users deal with the warnings is to surface them
> very obviously in the UI they use to interact with their Xen system.
> That is XenCenter/XenOrchestra/virt-manager/etc, and possibly the SSH
> MOTD - not a logfile that approximately noone reads.
>
> To make this happen, warnings need to be available somewhere which isn't
> the dmesg ring.  hypfs would be the obvious candidate at the moment.
Could we also taint Xen if there is a major warning?

Cheers,

--
Julien Grall