Re: kswapd hung tasks in 2.6.38-rc1

From: Dave Hansen
Date: Mon Jan 31 2011 - 18:20:16 EST


On Tue, 2011-02-01 at 00:13 +0100, Andrea Arcangeli wrote:
> On Mon, Jan 31, 2011 at 02:40:16PM -0800, Dave Hansen wrote:
> > Still not a very good data point, but I ran a heavy swap load for an
> > hour or so without reproducing this. But, it happened again after I
> > enabled transparent huge pages. I managed to get a sysrq-t dump out of
> > it:
> >
> > http://sr71.net/~dave/ibm/2.6.38-rc2-hang-0.txt
> >
> > khugepaged is one of the three running tasks. Note, I set both its
> > sleep timeouts to zero to stress it out a bit.
>
> sysrq+l? sysrq+t doesn't provide interesting info for running tasks.

I'll try to get a sysrq-l dump.

> > I'll keep trying to reproduce without THP.
>
> BTW, do you have prove locking enabled? With recent git I get a
> deadlock inside _raw_spin_unlock_irq with prove locking enabled and it
> goes away when I disable it.

Nope:

$ grep PROVE ../mhp-build/x86_64-elm3b82/.config
# CONFIG_PROVE_LOCKING is not set

Full .config is here

http://sr71.net/~dave/ibm/config-v2.6.38-rc2

-- Dave

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/