[PATCH v3 02/11] memcg: document cgroup dirty memory interfaces

[KAMEZAWA Hiroyuki]

On Tue, 19 Oct 2010 17:45:08 -0700
Greg Thelen <gthelen at google.com> wrote:

> KAMEZAWA Hiroyuki <kamezawa.hiroyu at jp.fujitsu.com> writes:
> > BTW, how about supporing dirty_limit_in_bytes when use_hierarchy=0 or
> > leave it as broken when use_hierarchy=1 ?  It seems we can only
> > support dirty_ratio when hierarchy is used.
> 
> I am not sure what you mean here.

When using dirty_ratio, we can check the value of dirty_ratio at setting it
and make guarantee that any children's dirty_ratio cannot exceeds it parent's.

If we guarantee that, we can keep dirty_ratio even under hierarchy.

When it comes to dirty_limit_in_bytes, we never able to do such kind of
controls. So, it will be broken and will do different behavior than
dirty_ratio.

So, not supporing dirty_bytes when use_hierarchy==1 for now sounds reasonable to me.

Thanks,
-Kame