On Sat, 2017-07-29 at 12:57 -0700, Dan Williams wrote: > On Fri, Jul 28, 2017 at 9:17 AM, 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'd rather flip this around and add a CONFIG_DM_DAX that gates whether > DM enables / links to the DAX core. I'll take a look at a patch. Thanks! Please also consider to move all DAX-related dm code into a separate source file such that the number of #ifdef CONFIG_DM_DAX statements can be kept to an absolute minimum. Bart.
