[dm-devel] awful request merge results while simulating high IOPS multipath

[Keith Busch]

On Wed, 25 Feb 2015, Mike Snitzer wrote:
> On Wed, Feb 25 2015 at  6:57pm -0500,
> Keith Busch <keith.busch at intel.com> wrote:
>
>> Yes, I'm also looking at blk-mq. It appears conversion helps a lot.
>
> Oh, so you've already started a conversion of request-based DM?

Actually no, I've only barely started looking at it. I'm guessing
improvement based on using a bio-based device mapper on top of nvme. In
my experience blk-mq performs similiar or better than bio on benchmarks,
so I hope it's a fair assumption here too.