Re: 2.6.17-rc4-mm1

Andrew Morton
2006-05-15T11:07:20Z

Eric Dumazet <dada1@cosmosbay.com> wrote:
>
> Hi Andrew
>
> It seems latest kernels have a problem in kmem_cache_destroy()

Mainline, or just -mm?

> On a dual opteron machine (NUMA), its quite easy do trigger the bug :
> doing a oprofile session like :
>
> opcontrol --setup --event=CPU_CLK_UNHALTED:100000
> --vmlinux=/usr/src/linux-2.6.17-rc4-mm1/vmlinux
> ...
> opcontrol --dump
> ...
> opcontrol --deinit <<<-- Triggers the bug
>
> slab error in kmem_cache_destroy(): cache `dcookie_cache': Can't free
> all objects
>
> Call Trace: <ffffffff80278aa4>{kmem_cache_destroy+212}
> <ffffffff802bc559>{dcookie_unregister+345}
> <ffffffff803bbe7a>{event_buffer_release+26}
> <ffffffff8027cee2>{__fput+98} <ffffffff80279ecd>{filp_close+93}
> <ffffffff8023003e>{put_files_struct+110}
> <ffffffff8023143a>{do_exit+650}
> <ffffffff802f58f1>{__up_write+33}
> <ffffffff80231bb8>{do_group_exit+200}
> <ffffffff802097ce>{system_call+126}
>
> # grep dcookie_cache /proc/slabinfo
> dcookie_cache 0 0 32 101 1 : tunables 120 60
> 8 : slabdata 0 0 0
>
>
> This problem is annoying, because in the oprofile case, we must reboot
> the machine to be able to start a new profile session.
>

sony:/home/akpm# opcontrol --setup --event=CPU_CLK_UNHALTED:100000 --vmlinux=/boot/vmlinux-2.6.17-rc4-mm1
sony:/home/akpm# opcontrol --start
Using 2.6+ OProfile kernel interface.
Reading module info.
Using log file /var/lib/oprofile/oprofiled.log
Daemon started.
Profiler running.
sony:/home/akpm# opcontrol --dump
sony:/home/akpm# opcontrol --stop
Stopping profiling.
sony:/home/akpm# opcontrol --deinit
Stopping profiling.
Killing daemon.
Unloading oprofile module
sony:/home/akpm# dmesg

<nothing>

Can you provide a more detailed method for reproducing this?