From: Jan Kara Subject: Re: [PATCH] mmap.2: Add description of MAP_SHARED_VALIDATE and MAP_SYNC Date: Thu, 12 Apr 2018 16:22:14 +0200 Message-ID: <20180412142214.fcxw3g2jxv6bvn7d@quack2.suse.cz> References: <20171101153648.30166-1-jack@suse.cz> <20171101153648.30166-20-jack@suse.cz> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Cc: xfs , Jan Kara , linux-nvdimm-hn68Rpc1hR1g9hUCZPvPmw@public.gmane.org, Linux API , "Darrick J . Wong" , Christoph Hellwig , Linux-MM , "linux-fsdevel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org" , Ext4 Developers List To: "Michael Kerrisk (man-pages)" Return-path: Content-Disposition: inline In-Reply-To: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: linux-nvdimm-bounces-hn68Rpc1hR1g9hUCZPvPmw@public.gmane.org Sender: "Linux-nvdimm" List-Id: linux-ext4.vger.kernel.org Hello Michael! On Thu 12-04-18 15:00:49, Michael Kerrisk (man-pages) wrote: > Hello Jan, > > I have applied your patch, and tweaked the text a little, and pushed > the result to the git repo. Thanks! > > +.B MAP_SHARED > > +type will silently ignore this flag. > > +This flag is supported only for files supporting DAX (direct mapping of persistent > > +memory). For other files, creating mapping with this flag results in > > +.B EOPNOTSUPP > > +error. Shared file mappings with this flag provide the guarantee that while > > +some memory is writeably mapped in the address space of the process, it will > > +be visible in the same file at the same offset even after the system crashes or > > +is rebooted. This allows users of such mappings to make data modifications > > +persistent in a more efficient way using appropriate CPU instructions. > > It feels like there's a word missing/unclear wording in the previous > line, before "using". Without that word, the sentence feels a bit > ambiguous. > > Should it be: > > persistent in a more efficient way *through the use of* appropriate > CPU instructions. > > or: > > persistent in a more efficient way *than using* appropriate CPU instructions. > > ? > > Is suspect the first is correct, but need to check. Yes, the first is correct. Honza -- Jan Kara SUSE Labs, CR