From mboxrd@z Thu Jan 1 00:00:00 1970 From: Matthew Wilcox Subject: Re: [PATCH v11 16/21] vfs,ext2: Remove CONFIG_EXT2_FS_XIP and rename CONFIG_FS_XIP to CONFIG_FS_DAX Date: Thu, 16 Oct 2014 17:52:56 -0400 Message-ID: <20141016215256.GJ11522@wil.cx> References: <1411677218-29146-1-git-send-email-matthew.r.wilcox@intel.com> <1411677218-29146-17-git-send-email-matthew.r.wilcox@intel.com> <20141016122618.GN19075@thinkos.etherlink> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: Matthew Wilcox , linux-fsdevel@vger.kernel.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org To: Mathieu Desnoyers Return-path: Content-Disposition: inline In-Reply-To: <20141016122618.GN19075@thinkos.etherlink> Sender: linux-kernel-owner@vger.kernel.org List-Id: linux-fsdevel.vger.kernel.org On Thu, Oct 16, 2014 at 02:26:18PM +0200, Mathieu Desnoyers wrote: > > + bool "Direct Access support" > > + depends on MMU > > + help > > + Direct Access (DAX) can be used on memory-backed block devices. > > + If the block device supports DAX and the filesystem supports DAX, > > + then you can avoid using the pagecache to buffer I/Os. Turning > > + on this option will compile in support for DAX; you will need to > > + mount the filesystem using the -o xip option. > > There is a mismatch between the documentation file (earlier patch): -o > dax, and this config description: -o xip. Whoops! Good catch. > I guess we might want to switch the mount option to "-o dax" and > document it as such, and since it should be usable transparently for the > same use-cases "-o xip" was enabling, we might want to keep parsing of > "-o xip" in the code for backward compatibility. > > Thoughts ? That's exactly what we do for ext2. For ext4, we force people to use the new -o dax option. We stop documenting that -o xip exist, and we print a message to tell people to switch over to -o dax.