Re: 2.6.23-rc1: BUG_ON in kmap_atomic_prot()

Alexey Dobriyan
2007-07-23T22:05:03Z

On Mon, Jul 23, 2007 at 02:11:37PM -0700, Andrew Morton wrote:
> On Tue, 24 Jul 2007 01:01:53 +0400
> Alexey Dobriyan <adobriyan@gmail.com> wrote:
>
> > On Tue, Jul 24, 2007 at 12:40:45AM +0400, Alexey Dobriyan wrote:
> > > > I had more complete info: http://article.gmane.org/gmane.linux.network/66966
> > > >
> > > > You're using DEBUG_PAGEALLOC, but I was not, so I think we can rule that out.
> > > >
> > > > I haven't worked out where that kmap_atomic() call is coming from yet.
> > > > Both traces point up into the page allocator, but I _think_ that's stack
> > > > gunk.
> > >
> > > Ahh, you suspect networking.
> > >
> > > Here, setup is 2 cheap-ass 100Mb realtek 8139 NICs, one to campus network
> > > receiving ~20 junk packets per second, one gathering netconsole output
> > > and ssh to it, no conntracks and fancy stuff.
> > >
> > > [reboots with cables physically unplugged]
> >
> > OK, I run gdb recompile, cat(1) every file in /usr/portage (shitload of
> > small files) with both cables unplugged. It all went fine for ~5 minutes
> > after that it crashed exactly same way after 10 secs after plugging one
> > of them.
>
> It'd be nice to get a clean trace. Are you able to obtain the full
> trace with CONFIG_FRAME_POINTER=y?

Sorry, no camera shot, finding camera requires wakening up M. :)

It took longer that usual, but here it is

kmap_atomic
get_page_from_freelist
__alloc_pages
cache_alloc_refill
__alloc_pages
cache_alloc_refill
kmem_cache_alloc
dst_alloc
ip_route_input
ip_rcv
netif_receive_skb
rtl8139_poll
net_rx_action
__do_softirq
do_softirq
irq_exit
do_IRQ
common_interrupt
handle_mm_fault
do_page_fault
error_core

much more loaded x86_64 box near also running 2.6.23-rc1 with debugging
turned on, using atl1 driver doesn't experience any crashes.

And I found 2.6.22-b91cba52e9b7b3f1c0037908a192d93a869ca9e5-x entry on
top of grub config which means b91cba52e9b7b3f1c0037908a192d93a869ca9e5
_without_ any debugging was OK.