(2012/05/12 6:17), Andrew Morton wrote:

On Fri, 11 May 2012 18:45:18 +0900
KAMEZAWA Hiroyuki [off-list ref] wrote:

quoted

The conditions are handled as -EBUSY, _now_.

The changelog is poor.  I rewrote it to

: hugetlb_force_memcg_empty() incorrectly returns 0 (success) when the
: cgroup is found to be busy.  Return -EBUSY instead.

But it still doesn't tell us the end-user-visible effects of the bug. 
It should.

Ah, sorry. How about this ?



The force_empty interface allows to make the memcg only when the cgroup
doesn't include any tasks.

	# echo 0 > /cgroup/xxxx/memory.force_empty

If cgroup isn't empty, force_empty does nothing and retruns -EBUSY in usual
memcg, memcontrol.c. But hugetlb implementation has inconsitency with
it and returns 0 and do nothing. Fix it to return -EBUSY.

Thanks,
-Kame