On Mon, 18 Dec 2006 18:02:20 +0100
Jiri Slaby <jirislaby at gmail.com> wrote:
> Rafael J. Wysocki wrote:
> > Hi,
> >
> > On Monday, 18 December 2006 12:20, Jiri Slaby wrote:
> >> Hi.
> >>
> >> I got this oops while suspending:
> >> [ 309.366557] Disabling non-boot CPUs ...
> >> [ 309.386563] CPU 1 is now offline
> >> [ 309.387625] CPU1 is down
> >> [ 309.387704] Stopping tasks ... done.
> >> [ 310.030991] Shrinking memory... -<0>divide error: 0000 [#1]
> >> [ 310.456669] SMP
> >> [ 310.456814] last sysfs file:
> >> /devices/pci0000:00/0000:00:1e.0/0000:02:08.0/eth0/statistics/collisions
> >> [ 310.456919] Modules linked in: eth1394 floppy ohci1394 ide_cd ieee1394 cdrom
> >> [ 310.457259] CPU: 0
> >> [ 310.457260] EIP: 0060:[<c0150c9a>] Not tainted VLI
> >> [ 310.457261] EFLAGS: 00210246 (2.6.20-rc1-mm1 #207)
> >> [ 310.457478] EIP is at shrink_slab+0x9e/0x169
> >
> > Looks like we have a problem with slab shrinking here.
> >
> > Could you please use gdb to check what exactly is at shrink_slab+0x9e?
>
> Sure, but not till Friday, sorry (I am away).
I think there's only one divide in there which can do this, so...
--- a/mm/vmscan.c~shrink_slab-handle-bad-shrinkers
+++ a/mm/vmscan.c
@@ -20,6 +20,7 @@
#include <linux/pagemap.h>
#include <linux/init.h>
#include <linux/highmem.h>
+#include <linux/kallsyms.h>
#include <linux/vmstat.h>
#include <linux/file.h>
#include <linux/writeback.h>
@@ -190,7 +191,13 @@ unsigned long shrink_slab(unsigned long
unsigned long total_scan;
unsigned long max_pass = (*shrinker->shrinker)(0, gfp_mask);
- delta = (4 * scanned) / shrinker->seeks;
+ if (!shrinker->seeks) {
+ print_symbol("shrinker %s has zero seeks\n",
+ (unsigned long)shrinker->shrinker);
+ delta = (4 * scanned) / DEFAULT_SEEKS;
+ } else {
+ delta = (4 * scanned) / shrinker->seeks;
+ }
delta *= max_pass;
do_div(delta, lru_pages + 1);
shrinker->nr += delta;
_
A quick grep shows that all set_shrinker() callers are doing the right
thing, so something kooky has happened.
