Re: [RFC 0/3] block: proportional based blk-throttling

From: Vivek Goyal
Date: Fri Jan 22 2016 - 09:43:46 EST

On Thu, Jan 21, 2016 at 05:41:57PM -0500, Tejun Heo wrote:

> A simple approximation of IO cost such as fixed cost
> per IO + cost proportional to IO size would do a far better job than
> just depending on bandwidth or iops and that requires approximating
> two variables over time. I'm not sure how easy / feasible that
> actually would be tho.

Hi Tejun,

"A fixed cost per IO sounds" like iops and "cost proportional to IO size"
sounds like bandwidth. I am wondering can we dynamically control both
bps and iops rate of cgroup based on cgroup weight and average bw/iops of
device queue. That way a cgroup can not get unfair share of disk neither
by throwing lots of small IOs, nor by sending down a small number of large

Will that be good enough.