Re: [PATCH V3 00/11] block-throttle: add .high limit

Hello,

On Tue, Oct 04, 2016 at 06:22:28PM +0200, Paolo Valente wrote:

Could you please elaborate more on this point?  BFQ uses sectors
served to measure service, and, on the all the fast devices on which
we have tested it, it accurately distributes
bandwidth as desired, redistributes excess bandwidth with any issue,
and guarantees high responsiveness and low latency at application and
system level (e.g., ~0 drop rate in video playback, with any background
workload tested).

The same argument as before.  Bandwidth is a very bad measure of IO
resources spent.  For specific use cases (like desktop or whatever),
this can work but not generally.

Could you please suggest me some test to show how sector-based
guarantees fails?

Well, mix 4k random and sequential workloads and try to distribute the
acteual IO resources.

Thanks.

-- 
tejun