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.