Re: [resend PATCH v2 11/33] dm: add dax_device and dax_operations support

[Mike Snitzer]

On Fri, Jul 28 2017 at 12:17pm -0400,
Bart Van Assche <Bart.VanAssche@xxxxxxx> wrote:

> On Mon, 2017-04-17 at 12:09 -0700, Dan Williams wrote:
> > diff --git a/drivers/md/Kconfig b/drivers/md/Kconfig
> > index b7767da50c26..1de8372d9459 100644
> > --- a/drivers/md/Kconfig
> > +++ b/drivers/md/Kconfig
> > @@ -200,6 +200,7 @@ config BLK_DEV_DM_BUILTIN
> >  config BLK_DEV_DM
> >  	tristate "Device mapper support"
> >  	select BLK_DEV_DM_BUILTIN
> > +	select DAX
> >  	---help---
> >  	  Device-mapper is a low level volume manager.  It works by allowing
> >  	  people to specify mappings for ranges of logical sectors.  Various
> 
> (replying to an e-mail of three months ago)
> 
> Hello Dan,
> 
> While building a v4.12 kernel I noticed that enabling device mapper support
> now unconditionally enables DAX. I think there are plenty of systems that use
> dm but do not need DAX. Have you considered to rework this such that instead
> of dm selecting DAX that DAX support is only enabled in dm if CONFIG_DAX is
> enabled?

I haven't but patches to do so would be welcomed.

Mike