Re: [PATCH 00/16] multiqueue for MMC/SD third try

Christoph Hellwig
2017-02-09T15:39:18Z

> What immediately jumps out at you is that linear read/writes
> perform just as nicely or actually better with MQ than with the
> old block layer.
>
> What is amazing is that just a little randomness, such as the
> find . > /dev/null immediately seems to visibly regress with MQ.
> My best guess is that it is caused by the absence of the block
> scheduler.

The block tree now has a basic deadline scheduler. So for now I'd
suggest to kick off the discussion on all these prep patches,
and then retest with 4.11-rc1 or 2 that will have the scheduler.