Re: IO scheduler based IO controller V10

From: Ryo Tsuruta
Date: Fri Sep 25 2009 - 03:09:21 EST


Hi,

Balbir Singh <balbir@xxxxxxxxxxxxxxxxxx> wrote:
> > > I think I must support dirty-ratio in memcg layer. But not yet.
> >
>
> We need to add this to the TODO list.
>
> > OR...I'll add a bufferred-write-cgroup to track bufferred writebacks.
> > And add a control knob as
> > bufferred_write.nr_dirty_thresh
> > to limit the number of dirty pages generetad via a cgroup.
> >
> > Because memcg just records a owner of pages but not records who makes them
> > dirty, this may be better. Maybe I can reuse page_cgroup and Ryo's blockio
> > cgroup code.
>
> Very good point, this is crucial for shared pages.
>
> >
> > But I'm not sure how I should treat I/Os generated out by kswapd.
> >
>
> Account them to process 0 :)

How about accounting them to processes who make pages dirty? I think
that a process which consumes more memory should get penalty. However,
this allows a page request process to use other's bandwidth, but If
a user doesn't want to swap-out the memory, the user should allocate
enough memory for the process by using memcg in advance.

Thanks,
Ryo Tsuruta
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/