Re: [PATCHSET block/for-next] IO cost model based work-conserving porportional controller

[Tejun Heo]

Hello, Paolo.

On Tue, Aug 20, 2019 at 05:04:25PM +0200, Paolo Valente wrote:
> and makes one fio instance generate I/O for each group.  The bandwidth
> reported above is that reported by the fio instance emulating the
> target client.
> 
> Am I missing something?

If you didn't configure QoS targets, the controller is using device
qdepth saturation as the sole guidance in determining whether the
device needs throttling.  Please try configuring the target latencies.
The bandwidth you see for single stream of rand ios should have direct
correlation with how the latency targets are configured.  The head
letter for the patchset has some examples.

Thanks.

-- 
tejun