From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Date: Tue, 30 Aug 2016 00:21:29 -0700 From: Christoph Hellwig To: Theodore Ts'o , Christoph Hellwig , Ross Zwisler , linux-kernel@vger.kernel.org, Andrew Morton , linux-nvdimm@ml01.01.org, Matthew Wilcox , Dave Chinner , linux-mm@kvack.org, Andreas Dilger , Alexander Viro , Jan Kara , linux-fsdevel@vger.kernel.org, linux-ext4@vger.kernel.org Subject: Re: [PATCH v2 2/9] ext2: tell DAX the size of allocation holes Message-ID: <20160830072129.GA10997@infradead.org> References: <20160823220419.11717-1-ross.zwisler@linux.intel.com> <20160823220419.11717-3-ross.zwisler@linux.intel.com> <20160825075728.GA11235@infradead.org> <20160826212934.GA11265@linux.intel.com> <20160829074116.GA16491@infradead.org> <20160829125741.cdnbb2uaditcmnw2@thunk.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20160829125741.cdnbb2uaditcmnw2@thunk.org> Sender: owner-linux-mm@kvack.org List-ID: On Mon, Aug 29, 2016 at 08:57:41AM -0400, Theodore Ts'o wrote: > It's been on my todo list. The only reason why I haven't done it yet > is because I knew you were working on a solution, and I didn't want to > do things one way for buffered I/O, and a different way for Direct > I/O, and disentangling the DIO code and the different assumptions of > how different file systems interact with the DIO code is a *mess*. It is. I have an almost working iomap direct I/O implementation, which simplifies a lot of this. Partially because it expects sane locking (a shared lock should be held over read, fortunately we now have i_rwsem for that) and allows less opt-in/out behavior, and partially just because we have so much better infrastructure now (iomap, bio chaining, iov_iters, ...). The iomap version is still work in progress, but I'm about to post a cut down version for block devices which reduces I/O latency by 20%. -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org