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

Marcelo Tosatti
2003-07-21T20:54:34Z

Just FYI, the 8way box is running for three days with LOTS of IO and
memory pressure:

hostname: dev8-005 (dev8-005.pdx.osdl.net) running linux

bash-2.05a$ uptime
2:03pm up 3 days, 3:14, 2 users, load average: 82.48, 91.67, 94.29
bash-2.05a$ vmstat 2
procs memory swap io system
cpu
r b w swpd free buff cache si so bi bo in cs us
sy id
1 77 2 3436 8232 77288 885880 0 0 3 12 13 16 4
9 8
0 78 3 3436 7300 77448 886596 0 0 108 12184 619 448 0
9 90
0 78 2 3436 11472 77760 880692 0 0 400 22922 836 2497 2
33 65
0 77 2 3428 7292 78176 884640 6 0 414 7858 761 511 0
11 88
0 77 3 3428 7392 78348 884776 0 0 238 9942 687 449 0
9 91
....

Interactivity under this extreme circumstances is impressive. Very good.

Great work Andrea, Mason and Jens. Thanks.

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.
>
> Regards,
> Stephan
>