Re: [PATCH v2 1/7] Basic kernel memory functionality for the Memory Controller

Kirill A. Shutemov
2011-09-18T19:05:11Z

On Sun, Sep 18, 2011 at 12:39:12AM -0300, Glauber Costa wrote:
> > No kernel memory accounting for root cgroup, right?
> Not sure. Maybe kernel memory accounting is useful even for root cgroup.
> Same as normal memory accounting... what we want to avoid is kernel
> memory limits. OTOH, if we are not limiting it anyway, accounting it is
> just useless overhead... Even the statistics can then be gathered
> through all
> the proc files that show slab usage, I guess?

It's better to leave root cgroup without accounting. At least for now.
We can add it later if needed.

> >
> >> @@ -3979,6 +3999,10 @@ static u64 mem_cgroup_read(struct cgroup *cont, struct cftype *cft)
> >> else
> >> val = res_counter_read_u64(&mem->memsw, name);
> >> break;
> >> + case _KMEM:
> >> + val = res_counter_read_u64(&mem->kmem, name);
> >> + break;
> >> +
> >
> > Always zero in root cgroup?
>
> Yes, if we're not accounting, it should be zero. WARN_ON, maybe?

-ENOSYS?

--
Kirill A. Shutemov