Re: [patch 0/4] [RFC] Another proportional weight IO controller

[Ryo Tsuruta <ryov@valinux.co.jp>]

Hi Vivek,

> > > Ryo, do you still want to stick to two level scheduling? Given the problem
> > > of it breaking down underlying scheduler's assumptions, probably it makes
> > > more sense to the IO control at each individual IO scheduler.
> > 
> > I don't want to stick to it. I'm considering implementing dm-ioband's
> > algorithm into the block I/O layer experimentally.
> 
> Thanks Ryo. Implementing a control at block layer sounds like another
> 2 level scheduling. We will still have the issue of breaking underlying
> CFQ and other schedulers. How to plan to resolve that conflict.

I think there is no conflict against I/O schedulers.
Could you expain to me about the conflict?

> What do you think about the solution at IO scheduler level (like BFQ) or
> may be little above that where one can try some code sharing among IO
> schedulers? 

I would like to support any type of block device even if I/Os issued
to the underlying device doesn't go through IO scheduler. Dm-ioband
can be made use of for the devices such as loop device.

Thanks,
Ryo Tsuruta