From: "Darrick J. Wong" <darrick.wong@oracle.com> To: Ira Weiny <ira.weiny@intel.com> Cc: Dan Williams <dan.j.williams@intel.com>, Jan Kara <jack@suse.cz>, Linux Kernel Mailing List <linux-kernel@vger.kernel.org>, Alexander Viro <viro@zeniv.linux.org.uk>, Dave Chinner <david@fromorbit.com>, Christoph Hellwig <hch@lst.de>, "Theodore Y. Ts'o" <tytso@mit.edu>, linux-ext4 <linux-ext4@vger.kernel.org>, linux-xfs <linux-xfs@vger.kernel.org>, linux-fsdevel <linux-fsdevel@vger.kernel.org> Subject: Re: [RFC PATCH V2 01/12] fs/stat: Define DAX statx attribute Date: Thu, 16 Jan 2020 10:04:21 -0800 Message-ID: <20200116180421.GD8235@magnolia> (raw) In-Reply-To: <20200116175501.GC24522@iweiny-DESK2.sc.intel.com> On Thu, Jan 16, 2020 at 09:55:02AM -0800, Ira Weiny wrote: > On Wed, Jan 15, 2020 at 09:39:35PM -0800, Darrick J. Wong wrote: > > On Wed, Jan 15, 2020 at 02:38:21PM -0800, Ira Weiny wrote: > > > On Wed, Jan 15, 2020 at 12:10:50PM -0800, Dan Williams wrote: > > > > On Wed, Jan 15, 2020 at 11:45 AM Ira Weiny <ira.weiny@intel.com> wrote: > > > > > > > > > > On Wed, Jan 15, 2020 at 09:38:34AM -0800, Darrick J. Wong wrote: > > > > > > On Wed, Jan 15, 2020 at 12:37:15PM +0100, Jan Kara wrote: > > > > > > > On Fri 10-01-20 11:29:31, ira.weiny@intel.com wrote: > > > > > > > > From: Ira Weiny <ira.weiny@intel.com> > > > > > > > > > > > > > [snip] > > > > > > > Sure, but for now I think referencing mmap for details on MAP_SYNC works. > > > > > > I suspect that we may have some word smithing once I get this series in and we > > > submit a change to the statx man page itself. Can I move forward with the > > > following for this patch? > > > > > > <quote> > > > STATX_ATTR_DAX > > > > > > The file is in the DAX (cpu direct access) state. DAX state > > > > Hmm, now that I see it written out, I <cough> kind of like "DAX mode" > > better now. :/ > > > > "The file is in DAX (CPU direct access) mode. DAX mode attempts..." > > Sure... now you tell me... ;-) > > Seriously, we could use mode here in the man page as this is less confusing to > say "DAX mode". > > But I think the code should still use 'state' because mode is just too > overloaded. You were not the only one who was thrown by my use of mode and I > don't want that confusion when we look at this code 2 weeks from now... > > https://www.reddit.com/r/ProgrammerHumor/comments/852og2/only_god_knows/ > > ;-) Ok, let's leave it alone for now then. I'm not even sure what 'DAX' stands for. Direct Access to ... Professor Xavier? 8-) > > > > > attempts to minimize software cache effects for both I/O and > > > memory mappings of this file. It requires a file system which > > > has been configured to support DAX. > > > > > > DAX generally assumes all accesses are via cpu load / store > > > instructions which can minimize overhead for small accesses, but > > > may adversely affect cpu utilization for large transfers. > > > > > > File I/O is done directly to/from user-space buffers and memory > > > mapped I/O may be performed with direct memory mappings that > > > bypass kernel page cache. > > > > > > While the DAX property tends to result in data being transferred > > > synchronously, it does not give the same guarantees of > > > synchronous I/O where data and the necessary metadata are > > > transferred together. > > > > (I'm frankly not sure that synchronous I/O actually guarantees that the > > metadata has hit stable storage...) > > I'll let you and Dan work this one out... ;-) Hehe. I think the wording here is fine. --D > Ira >
next prev parent reply index Thread overview: 55+ messages / expand[flat|nested] mbox.gz Atom feed top 2020-01-10 19:29 [RFC PATCH V2 00/12] Enable per-file/directory DAX operations V2 ira.weiny 2020-01-10 19:29 ` [RFC PATCH V2 01/12] fs/stat: Define DAX statx attribute ira.weiny 2020-01-15 11:37 ` Jan Kara 2020-01-15 17:38 ` Darrick J. Wong 2020-01-15 19:45 ` Ira Weiny 2020-01-15 20:10 ` Dan Williams 2020-01-15 22:38 ` Ira Weiny 2020-01-16 5:39 ` Darrick J. Wong 2020-01-16 6:05 ` Dan Williams 2020-01-16 6:18 ` Darrick J. Wong 2020-01-16 6:25 ` Dan Williams 2020-01-18 9:11 ` Dave Chinner 2020-01-16 17:55 ` Ira Weiny 2020-01-16 18:04 ` Darrick J. Wong [this message] 2020-01-16 18:52 ` Ira Weiny 2020-01-16 22:19 ` Darrick J. Wong 2020-01-17 11:58 ` Jan Kara 2020-01-10 19:29 ` [RFC PATCH V2 02/12] fs/xfs: Isolate the physical DAX flag from effective ira.weiny 2020-01-10 19:29 ` [RFC PATCH V2 03/12] fs/xfs: Separate functionality of xfs_inode_supports_dax() ira.weiny 2020-01-10 19:29 ` [RFC PATCH V2 04/12] fs/xfs: Clean up DAX support check ira.weiny 2020-01-10 19:29 ` [RFC PATCH V2 05/12] fs: remove unneeded IS_DAX() check ira.weiny 2020-01-16 9:38 ` Jan Kara 2020-01-16 18:47 ` Ira Weiny 2020-01-10 19:29 ` [RFC PATCH V2 06/12] fs/xfs: Check if the inode supports DAX under lock ira.weiny 2020-01-10 19:29 ` [RFC PATCH V2 07/12] fs: Add locking for a dynamic inode 'mode' ira.weiny 2020-01-13 22:12 ` Darrick J. Wong 2020-01-14 0:20 ` Ira Weiny 2020-01-14 1:03 ` Darrick J. Wong 2020-01-15 19:08 ` Ira Weiny 2020-01-16 5:40 ` Darrick J. Wong 2020-01-16 18:54 ` Ira Weiny 2020-01-10 19:29 ` [RFC PATCH V2 08/12] fs/xfs: Add lock/unlock mode to xfs ira.weiny 2020-01-13 22:19 ` Darrick J. Wong 2020-01-14 0:35 ` Ira Weiny 2020-01-15 0:57 ` Ira Weiny 2020-01-15 23:52 ` Ira Weiny 2020-01-16 9:24 ` Jan Kara 2020-01-16 19:12 ` Ira Weiny 2020-01-10 19:29 ` [RFC PATCH V2 09/12] fs: Prevent mode change if file is mmap'ed ira.weiny 2020-01-13 22:22 ` Darrick J. Wong 2020-01-14 0:46 ` Ira Weiny 2020-01-14 1:30 ` Darrick J. Wong 2020-01-14 17:53 ` Ira Weiny 2020-01-15 11:34 ` Jan Kara 2020-01-15 18:24 ` Ira Weiny 2020-01-15 10:21 ` David Laight 2020-01-15 17:53 ` Ira Weiny 2020-01-10 19:29 ` [RFC PATCH V2 10/12] fs/xfs: Fix truncate up ira.weiny 2020-01-13 22:27 ` Darrick J. Wong 2020-01-14 0:40 ` Ira Weiny 2020-01-14 1:14 ` Darrick J. Wong 2020-01-14 19:00 ` Ira Weiny 2020-01-14 19:39 ` Ira Weiny 2020-01-10 19:29 ` [RFC PATCH V2 11/12] fs/xfs: Clean up locking in dax invalidate ira.weiny 2020-01-10 19:29 ` [RFC PATCH V2 12/12] fs/xfs: Allow toggle of effective DAX flag ira.weiny
Reply instructions: You may reply publicly to this message via plain-text email using any one of the following methods: * Save the following mbox file, import it into your mail client, and reply-to-all from there: mbox Avoid top-posting and favor interleaved quoting: https://en.wikipedia.org/wiki/Posting_style#Interleaved_style * Reply using the --to, --cc, and --in-reply-to switches of git-send-email(1): git send-email \ --in-reply-to=20200116180421.GD8235@magnolia \ --to=darrick.wong@oracle.com \ --cc=dan.j.williams@intel.com \ --cc=david@fromorbit.com \ --cc=hch@lst.de \ --cc=ira.weiny@intel.com \ --cc=jack@suse.cz \ --cc=linux-ext4@vger.kernel.org \ --cc=linux-fsdevel@vger.kernel.org \ --cc=linux-kernel@vger.kernel.org \ --cc=linux-xfs@vger.kernel.org \ --cc=tytso@mit.edu \ --cc=viro@zeniv.linux.org.uk \ /path/to/YOUR_REPLY https://kernel.org/pub/software/scm/git/docs/git-send-email.html * If your mail client supports setting the In-Reply-To header via mailto: links, try the mailto: link
Linux-XFS Archive on lore.kernel.org Archives are clonable: git clone --mirror https://lore.kernel.org/linux-xfs/0 linux-xfs/git/0.git # If you have public-inbox 1.1+ installed, you may # initialize and index your mirror using the following commands: public-inbox-init -V2 linux-xfs linux-xfs/ https://lore.kernel.org/linux-xfs \ linux-xfs@vger.kernel.org public-inbox-index linux-xfs Example config snippet for mirrors Newsgroup available over NNTP: nntp://nntp.lore.kernel.org/org.kernel.vger.linux-xfs AGPL code for this site: git clone https://public-inbox.org/public-inbox.git