[techtalk] tty lockup

[David Merrill]

On Fri, Mar 09, 2001 at 02:56:45PM +0000, James A. Sutherland wrote:
> On Fri, 9 Mar 2001, David Merrill wrote:
> 
> > On Fri, Mar 09, 2001 at 02:32:51PM +0000, James A. Sutherland wrote:
> > > On Fri, 9 Mar 2001, David Merrill wrote:
> > >
> > > > Hi,
> > > >
> > > > I was running red-carpet and it ate up ALL my available ram. I killed
> > > > it. Now I can get no responsiveness at the console. I am logged in
> > > > from another machine right now so I can send this mail.
> > > >
> > > > I suspect that the oom condition caused Linux to kill (somewhat)
> > > > random processes, and one of them was my tty (mgetty?) Am I on track
> > > > or way off base?
> > > >
> > > > Any tips on how to fix this?
> > >
> > > A tty isn't a process, so it can't have killed that. It could have killed
> > > the mingetty running there, but init would have respawned it straight
> > > away.
> > >
> > > The OOM killer in Linux is a fairly recent addition (partly my concept);
> > > until it was added, random processes would have died off; with it, the
> > > biggest memory hog would be killed (red-carpet in this case).
> >
> > Yes, you're right. I've been following, loosely, the vm and oom
> > conversations in l-k (or in kernel traffic, actually) but only for the
> > 2.4 series.
> 
> You're still on 2.2, I take it? I've been running 2.4 without any problems
> for some months now.

Yes, 2.2.18.

> > > Can you switch from one VC (virtual console) to another? Did you have the
> > > "Magic Alt+SysRq" support included in the kernel? If so, can you do an
> > > SAK? (Alt+SysRq+K - kills all processes on the current VC, which should
> > > give you a clean login screen.)
> >
> > I cannot. I don't have the magic sysrq enabled, not being a kernel
> > hacker and not expecting to need it. That'll larn me.
> 
> Alt+SysRq can be very useful in tight corners like this... I had Adobe
> Acrobat Reader blow up on me recently, taking out X in the process. A
> quick SAK later, and a few minutes of disk thrashing, and everything was
> back to normal!
> 
> > Hmmm. I just had the thought that I might try resetting the runlevel.
> > Is that reasonable, or madness?
> 
> Could try that, yes... Can you switch VC's, though?

Nope. Okay, I'll try it from the local console tonight. Thanks!

-- 
Dr. David C. Merrill                     http://www.lupercalia.net
Linux Documentation Project                   david at lupercalia.net
Collection Editor & Coordinator            http://www.linuxdoc.org
                                       Finger me for my public key

Van Roy's Law:
	Honesty is the best policy - there's less competition.

Van Roy's Truism:
	Life is a whole series of circumstances beyond your control.