[dm-devel] Serial console is causing system lock-up

[Sergey Senozhatsky]

On (03/07/19 09:26), Mikulas Patocka wrote:
> On Thu, 7 Mar 2019, John Stoffel wrote:
> 
> > The real problem is the disconnect between serial console speed and
> > capacity in bits/sec and that of the regular console.  Serial, esp at
> > 9600 baud is just a slow and limited resource which needs to be
> > handled differently than a graphical console.
> >
> > I'm also big on ratelimiting messages, even critical warning
> > messages.  Too much redundant info doesn't help anyone.  And what a
> > subsystem thinks is critical, may not be critical to the system as a
> > whole.
> 
> Perhaps a proper solution would be to drop excessive messages to serial 
> console unless Oops or BUG has happened?

Technically, we can have a per-console loglevel configuration. We have
several use cases for this already. Slower consoles will filter out more
messages and print only ERR/CRIT/ALERT/EMERG.

dm-integrity uses WARN level, which is below ERR; so it seems that
per-console loglevel can do the trick.

	-ss