Re: 4.14 backport request for dbdda842fe96f: "printk: Add console owner and waiter logic to load balance console writes"

Steven Rostedt
2018-10-01T20:29:58Z

On Mon, 1 Oct 2018 22:13:10 +0200
Pavel Machek <pavel@ucw.cz> wrote:

> > > [1] https://lore.kernel.org/lkml/20180409081535.dq7p5bfnpvd3xk3t@pathway.suse.cz/T/#u
> > >
> > > Serial console logs leading up to the deadlock. As can be seen the stack trace
> > > was incomplete because the printing path hit a timeout.
> >
> > I'm fine with having this backported.
>
> Dunno. Is the patch perhaps a bit too complex? This is not exactly
> trivial bugfix.
>
> pavel@duo:/data/l/clean-cg$ git show dbdda842fe96f | diffstat
> printk.c | 108
> ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++-
>
> I see that it is pretty critical to Daniel, but maybe kernel with
> console locking redone should no longer be called 4.4?

But it prevents a deadlock.

I usually weigh backporting as benefit vs risk. And I believe the
benefit outweighs the risk in this case.

-- Steve