From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from esa5.hgst.iphmx.com ([216.71.153.144]:23676 "EHLO esa5.hgst.iphmx.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751882AbdG1QRz (ORCPT ); Fri, 28 Jul 2017 12:17:55 -0400 From: Bart Van Assche To: "dan.j.williams@intel.com" , "linux-nvdimm@lists.01.org" CC: "dm-devel@redhat.com" , "linux-kernel@vger.kernel.org" , "toshi.kani@hpe.com" , "linux-block@vger.kernel.org" , "hch@lst.de" , "snitzer@redhat.com" , "linux-fsdevel@vger.kernel.org" Subject: Re: [resend PATCH v2 11/33] dm: add dax_device and dax_operations support Date: Fri, 28 Jul 2017 16:17:07 +0000 Message-ID: <1501258623.2413.3.camel@wdc.com> References: <149245612770.10206.15496018295337908594.stgit@dwillia2-desk3.amr.corp.intel.com> <149245618859.10206.13182319600260215993.stgit@dwillia2-desk3.amr.corp.intel.com> In-Reply-To: <149245618859.10206.13182319600260215993.stgit@dwillia2-desk3.amr.corp.intel.com> Content-Type: text/plain; charset="iso-8859-1" MIME-Version: 1.0 Sender: linux-block-owner@vger.kernel.org List-Id: linux-block@vger.kernel.org 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 u= se dm but do not need DAX. Have you considered to rework this such that instea= d of dm selecting DAX that DAX support is only enabled in dm if CONFIG_DAX is enabled? Thanks, Bart.