From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Date: Fri, 28 Jul 2017 13:48:30 -0400 From: Mike Snitzer To: Bart Van Assche Cc: "dan.j.williams@intel.com" , "linux-nvdimm@lists.01.org" , "dm-devel@redhat.com" , "linux-kernel@vger.kernel.org" , "toshi.kani@hpe.com" , "linux-block@vger.kernel.org" , "hch@lst.de" , "linux-fsdevel@vger.kernel.org" Subject: Re: [resend PATCH v2 11/33] dm: add dax_device and dax_operations support Message-ID: <20170728174830.GA13772@redhat.com> References: <149245612770.10206.15496018295337908594.stgit@dwillia2-desk3.amr.corp.intel.com> <149245618859.10206.13182319600260215993.stgit@dwillia2-desk3.amr.corp.intel.com> <1501258623.2413.3.camel@wdc.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1501258623.2413.3.camel@wdc.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: On Fri, Jul 28 2017 at 12:17pm -0400, Bart Van Assche 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