[BUG] 2.6.17-rc3 : slab error in kmem_cache_destroy(): cache `dcookie_cache': Can't free all objects

[BUG] 2.6.17-rc3 : slab error in kmem_cache_destroy(): cache `dcookie_cache': Can't free all objects

[Eric Dumazet]

It seems reproductible, on dual Opteron (x86_64), NUMA enabled.

When issuing : 

opcontrol --deinit

slab error in kmem_cache_destroy(): cache `dcookie_cache': Can't free all 
objects

Call Trace: <ffffffff802715ef>{kmem_cache_destroy+175}
       <ffffffff802b4c48>{dcookie_unregister+280} 
<ffffffff803a4ff7>{event_buffer_release+23}
       <ffffffff802767a8>{__fput+88} <ffffffff8027382d>{filp_close+93}
       <ffffffff8022ee2e>{put_files_struct+110} 
<ffffffff8023025a>{do_exit+650}
       <ffffffff802ec581>{__up_write+33} <ffffffff80230998>{do_group_exit+200}
       <ffffffff80209cbe>{system_call+126}

# grep dcookie_cache /proc/slabinfo
dcookie_cache          0      0     32  112    1 : tunables  120   60    8 : 
slabdata      0      0      0


After that, oprofile cannot work anymore, since the dcookie_cache cannot be 
re-created...

kmem_cache_create: duplicate cache dcookie_cache

Call Trace: <ffffffff802726ff>{kmem_cache_create+1455}
       <ffffffff80285f55>{do_path_lookup+629} 
<ffffffff803a4e20>{event_buffer_open+0}
       <ffffffff802b4dc0>{dcookie_register+96} 
<ffffffff803a4e5a>{event_buffer_open+58}
       <ffffffff80273aad>{__dentry_open+237} 
<ffffffff80273cca>{do_filp_open+42}
       <ffffffff80273935>{get_unused_fd+101} 
<ffffffff80273d36>{do_sys_open+86}
       <ffffffff80209cbe>{system_call+126}


Eric Dumazet