Re: [PATCH v3 09/11] memcg: add cgroupfs interface to memcg dirty limits

Daisuke Nishimura
2010-10-20T03:49:04Z

On Wed, 20 Oct 2010 12:31:10 +0900
Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp> wrote:

> On Mon, 18 Oct 2010 17:39:42 -0700
> Greg Thelen <gthelen@google.com> wrote:
>
> > Add cgroupfs interface to memcg dirty page limits:
> > Direct write-out is controlled with:
> > - memory.dirty_ratio
> > - memory.dirty_limit_in_bytes
> >
> > Background write-out is controlled with:
> > - memory.dirty_background_ratio
> > - memory.dirty_background_limit_bytes
> >
> > Other memcg cgroupfs files support 'M', 'm', 'k', 'K', 'g'
> > and 'G' suffixes for byte counts. This patch provides the
> > same functionality for memory.dirty_limit_in_bytes and
> > memory.dirty_background_limit_bytes.
> >
> > Signed-off-by: Andrea Righi <arighi@develer.com>
> > Signed-off-by: Balbir Singh <balbir@linux.vnet.ibm.com>
> > Signed-off-by: Greg Thelen <gthelen@google.com>
>
> Acked-by: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp>
>
> One question: shouldn't we return -EINVAL when writing to dirty(_background)_limit_bytes
> a bigger value than that of global one(if any) ? Or do you intentionally
> set the input value without comparing it with the global value ?
> But, hmm..., IMHO we should check it in __mem_cgroup_dirty_param() or something
> not to allow dirty pages more than global limit.
>
Oh, Kamazawa-san has just send a fix for this problem :)
Please ignore this comment.

Thanks,
Daisuke Nishimura.