Re: [RFC] block: deprecate choosing elevator via boot param

From: Jens Axboe
Date: Wed Aug 30 2017 - 10:24:39 EST


On 08/14/2017 03:27 AM, Oleksandr Natalenko wrote:
> Setting I/O scheduler via kernel command line is not flexible enough
> anymore. Different schedulers might be desirable for different types
> of devices (SSDs and HDDs, for instance). Moreover, setting elevator
> while using blk-mq framework does not work in this way already.
>
> This commit enables warning if user specifies "elevator" boot param.
> Removing this option at all might be considered in some future.

Not a huge fan of doing it like this, it'll just add a bunch of noise to
the dmesg output that people will ignore. It doesn't bring us closer to
being able to remove the option.

I think we should just let it die over time. This will happen naturally
since the blk-mq scheduling framework does not support it. Once we have
everything converted, the option will end up doing nothing. Then we can
eventually kill it.

--
Jens Axboe