Re: Simple script that locks up my box with recent kernels

Jesper Juhl
2006-11-22T10:55:11Z

On 22/11/06, Jens Axboe <jens.axboe@oracle.com> wrote:
> On Tue, Nov 21 2006, Linus Torvalds wrote:
> > I don't think we use any irq-disable locking in the VM itself, but I could
> > imagine some nasty situation with the block device layer getting into a
> > deadlock with interrupts disabled when it runs out of queue entries and
> > cannot allocate more memory..
>
> Not likely. Request allocation is done with GFP_NOIO and backed by a
> memory pool, so as long the vm doesn't go totally nuts because
> __GFP_WAIT is set, we should be safe there. If it did go crazy, I
> suspect a sysrq-t would still work.
>
> If bouncing is involved for swap, we do have a potential deadlock issue
> that isn't fixed yet. I just whipped up this completely untested patch,
> it should shed some light on that issue.
>
Thanks Jens, I'll apply that later tonight and force a few lockups and
see if I get any extra details with that patch.

--
Jesper Juhl <jesper.juhl@gmail.com>
Don't top-post http://www.catb.org/~esr/jargon/html/T/top-post.html
Plain text mails only, please http://www.expita.com/nomime.html