Re: VM lockup with 2.4.8 / 2.4.8pre8

[Roy C. Bixler]

On Mon, 13 Aug 2001, I wrote:
> I have just inadvertantly encountered a VM lockup with Linux 2.4.8.  The
> KDE kspread application couldn't handle one spreadsheet I gave it and it
> ran away consuming all memory in the system.  When I first ran into the
> trouble, my machine has 384 Meg. RAM and 184 Meg. of swap.  I tried
> 2.4.8pre8 and the lockup still occurs.  I have increased my swap to 768
> Meg. and 2.4.8 still locks up.  I tried 2.4.7 and it doesn't lockup - it
> correctly OOM kills the runaway process.
> 
> The system feels responcive up until it locks up.  Running 'top' while it
> happens show that the lockup occurs at about the point where swap runs
> out.  Other system details: it is running the latest Debian snapshot.

I've managed to do a little more tracing on this.  I've tried this test on
2.4.8-pre1 and it eventually kills the culprit process.  I tried again
under 2.4.8 and, since the Sys-Rq key combinations worked while the system
was otherwise completely quiet (no disk activity) and unresponcive, I
tried hitting Sys-Rq-P a few times and the stack traces always looked like
this:

do_try_to_free_pages
kswapd
kernel_thread

or

swap_out_vma
swap_out_mm
swap_out
refill_active_zone
refill_inactive
do_try_to_free_pages
kswapd
kernel_thread

I also just tried 2.4.9-pre3 and the system locked before swap filled up
with a screen full of '__alloc_pages: order 0 allocation failed' type
messages.

-- 
Roy Bixler
The University of Chicago Press
[e-mail]