Re: [PATCH RFC 09/22] block, cfq: replace CFQ with the BFQ-v0 I/O scheduler

[Christoph Hellwig]

On Fri, Mar 04, 2016 at 01:10:31PM -0500, Austin S. Hemmelgarn wrote:
> 1. This all started long before blk-mq hit mainline.

Whoe cares? :)

> 2. There's still a decent amount of block drivers that don't support blk-mq.
> Last time I looked (around the time 4.4 came out), I saw the following that
> either obviously don't support it, or are ambiguous as to whether they
> support it or not.  Here's a list of just the ones I know are being used on
> existing systems running relatively recent kernel versions, not including

There is no ambiguouity.  You clearly named a few ones that aren't
converted, but also a lot of make_request_fn based drivers which don't
support any I/O scheduler.

But that whole point is that anything actively developed should move
over.