On Tue, May 05, 2015 at 09:45:21AM -0400, Tejun Heo wrote: > On Tue, May 05, 2015 at 12:45:43PM +0300, Vladimir Davydov wrote: > > root->ino_ida is used for kernfs inode number allocations. Since IDA has > > a layered structure, different IDs can reside on the same layer, which > > is currently accounted to some memory cgroup. The problem is that each > > kmem cache of a memory cgroup has its own directory on sysfs (under > > /sys/fs/kernel/<cache-name>/cgroup). If the inode number of such a > > directory or any file in it gets allocated from a layer accounted to the > > cgroup which the cache is created for, the cgroup will get pinned for > > good, because one has to free all kmem allocations accounted to a cgroup > > in order to release it and destroy all its kmem caches. That said we > > must not account layers of ino_ida to any memory cgroup. > > > > Since per net init operations may create new sysfs entries directly > > (e.g. lo device) or indirectly (nf_conntrack creates a new kmem cache > > per each namespace, which, in turn, creates new sysfs entries), an easy > > way to reproduce this issue is by creating network namespace(s) from > > inside a kmem-active memory cgroup. > > > > Signed-off-by: Vladimir Davydov <vdavydov@xxxxxxxxxxxxx> > > Man, that's nasty. For the kernfs part, > > Acked-by: Tejun Heo <tj@xxxxxxxxxx> Thanks. > > Can you please repost this patch w/ Greg KH cc'd? OK. -- To unsubscribe from this list: send the line "unsubscribe cgroups" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
