Re: [RFC][PATCH 2/5] memcg: uncharge in batched manner

Balbir Singh
2009-08-31T12:23:19Z

* KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> [2009-08-31 21:14:10]:

> Balbir Singh wrote:
> >> > Does this effect deleting of a group and delay it by a large amount?
> >> >
> >> plz see what cgroup_release_and_xxxx fixed. This is not for delay
> >> but for race-condition, which makes rmdir sleep permanently.
> >>
> >
> > I've seen those patches, where rmdir() can hang. My conern was time
> > elapsed since we do css_get() and do a cgroup_release_and_wake_rmdir()
> >
> plz read unmap() and truncate() code.
> The number of pages handled without cond_resched() is limited.
>
>

I understand that part, I was referring to tasks stuck doing rmdir()
while we do batched uncharge, will it be very visible to the end user?
cond_resched() is bad in this case.. since it means we'll stay longer
before we release the cgroup.

--
Balbir