Re: Bug Report: 2.4.22-pre5: BUG in page_alloc (fwd)

Marcelo Tosatti
2003-07-21T19:29:12Z

On Mon, 21 Jul 2003, Stephan von Krawczynski wrote:

> On Mon, 21 Jul 2003 12:20:33 -0400
> Andrea Arcangeli <andrea@suse.de> wrote:
>
> > > I managed to freeze the pre7 box within these few hours. There was no nfs
> > > involved, only tar-to-tape.
> > > I switched back to 2.4.21 to see if it is still stable.
> > > Is there a possibility that the i/o-scheduler has another flaw somewhere
> > > (just like during mount previously) ...
> >
> > is it a scsi tape?
>
> yes.
>
> > Is the tape always involved?
>
> No, I experience both freeze during nfs-only action and freeze during
> tar-to-scsi-tape.
> My feelings are that the freeze does (at least in the nfs case) not happen
> during high load but rather when load seems relatively light. Handwaving one
> could say it looks rather like an I/O sched starvation issue than breakdown
> during high load. Similar to the last issue.
>
> > there are st.c updates
> > between 2.4.21 to 22pre7. you can try to back them out.
>
> Hm, which?
>
> > [...]
> > You should also provide a SYSRQ+P/T of the hang or we can't debug it at
> > all.
>
> Well, I really tried hard to produce something, but failed so far, if I had
> more time I would try a serial console hoping that it survives long enough to
> show at least _something_.
> The only thing I ever could see was the BUG in page-alloc thing from the
> beginning of this thread.

Stephan,

I'm sending you the scsi tape driver changes in 2.4.22-pre so you can
revert them (in private in a few minutes).

If that doesnt make us spot the problem, can you PLEASE find out in which
-pre the problem starts ?

Thank you