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

From: Tejun Heo
Date: Tue Oct 04 2016 - 15:14:58 EST

Hello, Paolo.

On Tue, Oct 04, 2016 at 09:02:47PM +0200, Paolo Valente wrote:
> That's exactly what BFQ has succeeded in doing in all the tests
> devised so far. Can you give me a concrete example for which I can
> try with BFQ and with any other mechanism you deem better. If
> you are right, numbers will just make your point.

Hmm... I think we already discussed this but here's a really simple
case. There are three unknown workloads A, B and C and we want to
give A certain best-effort guarantees (let's say around 80% of the
underlying device) whether A is sharing the device with B or C.

I get that bfq can be a good compromise on most desktop workloads and
behave reasonably well for some server workloads with the slice
expiration mechanism but it really isn't an IO resource partitioning