Re: 2.6.17-rc4-mm1

Eric Dumazet
2006-05-15T10:09:29Z

Hi Andrew

It seems latest kernels have a problem in kmem_cache_destroy()

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.

Eric