From mboxrd@z Thu Jan 1 00:00:00 1970 From: Theodore Ts'o Subject: Re: [RFC][PATCH 1/2] Add a super operation for writeback Date: Tue, 3 Jun 2014 10:57:49 -0400 Message-ID: <20140603145749.GB12890@thunk.org> References: <538B9DEE.20800@phunq.net> <538C360F.7020901@ontolinux.com> <20140603033940.GB14410@dastard> <538D5D78.6040102@ontolinux.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: Dave Chinner , Daniel Phillips , Linux Kernel , Linux FS Devel , Linus Torvalds , Andrew Morton , OGAWA Hirofumi To: Christian Stroetmann Return-path: Content-Disposition: inline In-Reply-To: <538D5D78.6040102@ontolinux.com> Sender: linux-kernel-owner@vger.kernel.org List-Id: linux-fsdevel.vger.kernel.org On Tue, Jun 03, 2014 at 07:30:32AM +0200, Christian Stroetmann wrote: > In general, I do not believe that the complexity problems of soft updates, > atomic writes, and related techniques can be solved by hand/manually. So my > suggestion is to automatically handle the complexity problem of e.g. > dependancies in a way that is comparable to a(n on-the-fly) file-system > compiler so to say that works on a very large dependancy graph (having > several billions of graph vertices actually). And at this point an > abstraction like it is given with Featherstitch helps to feed and control > this special FS compiler. Well, if you want to try to implement something like this, go for it! I'd be very curious to see how well (a) how much CPU overhead it takes to crunch on a dependency graph with billions of vertices, and (b) how easily can it be to express these dependencies and maintainable such a dependency language would be. Sounds like a great research topic, and I'll note the Call For Papers for FAST 2015 is out, and if you can solve these problems, it would make a great FAST 2015 submission: https://www.usenix.org/conference/fast15/call-for-papers Cheers, - Ted