From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from bifrost.lang.hm (mail.lang.hm [64.81.33.126]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (Client did not present a certificate) by huchra.bufferbloat.net (Postfix) with ESMTPS id C787921F342 for ; Sun, 31 Aug 2014 12:37:10 -0700 (PDT) Received: from asgard.lang.hm (asgard.lang.hm [10.0.0.100]) by bifrost.lang.hm (8.13.4/8.13.4/Debian-3) with ESMTP id s7VJb7NE003046; Sun, 31 Aug 2014 12:37:07 -0700 Date: Sun, 31 Aug 2014 12:37:07 -0700 (PDT) From: David Lang X-X-Sender: dlang@asgard.lang.hm To: "Theodore Ts'o" In-Reply-To: <20140831164531.GE8974@thunk.org> Message-ID: References: <20140830213451.GA30271@thunk.org> <20140831013837.GB8974@thunk.org> <20140831164531.GE8974@thunk.org> User-Agent: Alpine 2.02 (DEB 1266 2009-07-14) MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII; format=flowed Cc: cerowrt-devel@lists.bufferbloat.net Subject: Re: [Cerowrt-devel] Is there a particular reason cerowrt isn't using UBIFS? X-BeenThere: cerowrt-devel@lists.bufferbloat.net X-Mailman-Version: 2.1.13 Precedence: list List-Id: Development issues regarding the cerowrt test router project List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sun, 31 Aug 2014 19:37:10 -0000 On Sun, 31 Aug 2014, Theodore Ts'o wrote: > On Sun, Aug 31, 2014 at 12:05:52AM -0700, David Lang wrote: >> >> One other place this sort of thing is likely to be useful is for Raspberry >> Pi and other small (embedded by some defintions) systems that use SD cards >> for their OS system. The I/O to the storage is so slow that the saved I/O >> time is likely to more than cover the cost of the decompression. > > Yeah, that's the main argument I've heard for wanting to do > decompression; it's to speed up I/O when using HDD's and cheap flash > that has a minimal number of flash channels. As a datapoint in this discussin, take a look at the openwrt thread [OpenWrt-Devel] Toolchain issue: Significant decrease in performance of binaries produced by Barrier Breaker relative to Attitude Adjustment Apparently with BB they changed the gcc options on mips to produce 16 bit code because it results in smaller binaries, but this cripples performance in some cases It doesn't answer your funding issue, but it shows another case of people being very sensitive to storage size. David Lang >> Raspberry Pi systems have had to move to 4G cards as their base because it's >> just not possible to have the standard install do more than boot on a 2G >> card. > > 2G SD cards -- $42.95 for a 10-pack > 4G SD cards -- $53.95 for a 10-pack > > I have a design for adding compression, but except as a hobby effort, > I've had a lot of trouble finding a company who would be willing to > support an engineer to actually do the effort. :-( > > Unless the company is making a truly vast number of devices, and are > very sensitive to the BOM cost, it might not make sense from an > engineering / business plan point of view. > > So it will probably be something I do "for fun", when I can find the > time.... and there are a lot of other projects where companies are > willing to sponsor engineers to add new features, such as encryption, > reflink support, data checksums, etc., where if I can help them land > those features, it's unfortunately going to be higher priority than my > personally working on compression support for ext4. > > But if someone is interested in working on it, they should talk to me; > I'd be happy to work with someone interested in working on the > project. > > - Ted >