Re: [dm-devel] [PATCH 0/2] dm-band: The I/O bandwidth controller: Overview

[Hirokazu Takahashi <taka@valinux.co.jp>]

Hi,

> On Wed, Jan 23, 2008 at 09:53:50PM +0900, Ryo Tsuruta wrote:
> > Dm-band gives bandwidth to each job according to its weight, 
> > which each job can set its own value to.
> > At this time, a job is a group of processes with the same pid or pgrp or uid.
> 
> It seems to rely on 'current' to classify bios and doesn't do it until the map
> function is called, possibly in a different process context, so it won't
> always identify the original source of the I/O correctly:

Yes, this should be mentioned in the document with the current implementation
as you pointed out.

By the way, I think once a memory controller of cgroup is introduced, it will
help to track down which cgroup is the original source.

> people need to take
> this into account when designing their group configuration and so this should
> be mentioned in the documentation.
>
> I've uploaded it here while we consider ways we might refine the architecture and
> interfaces etc.:
> 
>   http://www.kernel.org/pub/linux/kernel/people/agk/patches/2.6/editing/dm-add-band-target.patch
> 
> Alasdair
> -- 
> agk@redhat.com

Thank you,
Hirokazu Takahashi.