kmem.slabinfo sysfs

[Hemanth Kumar]

Hi Greg, 

 I was working v3.10 on sysfs and I came across this when we do 
 cat /sys/fs/cgroup/memory/memory.kmem.slabinfo 

 it throws the error "Input/output error"

 ls -l /sys/fs/cgroup/memory/memory.kmem.slabinfo
 file permission is 0444  but still it gives "Input/output error" (I checked this as user and root)

 This is the commit id    749c54151a6e5b229e4ae067dbc651e54b161fbc v3.8-rc1,

 Did I miss some thing or this is a issue.

 Regards,