From owner-freebsd-hackers Tue Jun 4 23:49:25 1996 Return-Path: owner-hackers Received: (from root@localhost) by freefall.freebsd.org (8.7.5/8.7.3) id XAA13681 for hackers-outgoing; Tue, 4 Jun 1996 23:49:25 -0700 (PDT) Received: from dyson.iquest.net (dyson.iquest.net [198.70.144.127]) by freefall.freebsd.org (8.7.5/8.7.3) with ESMTP id XAA13672 for ; Tue, 4 Jun 1996 23:49:21 -0700 (PDT) Received: (from root@localhost) by dyson.iquest.net (8.7.5/8.6.9) id BAA00451; Wed, 5 Jun 1996 01:48:15 -0500 (EST) From: "John S. Dyson" Message-Id: <199606050648.BAA00451@dyson.iquest.net> Subject: Re: Breaking ffs - speed enhancement? To: jehamby@lightside.com (Jake Hamby) Date: Wed, 5 Jun 1996 01:48:15 -0500 (EST) Cc: terry@lambert.org, bde@zeta.org.au, dufault@hda, hackers@freebsd.org In-Reply-To: from "Jake Hamby" at Jun 2, 96 02:21:53 pm Reply-To: dyson@freebsd.org X-Mailer: ELM [version 2.4 PL24 ME8] MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: owner-hackers@freebsd.org X-Loop: FreeBSD.org Precedence: bulk > > Of course either solution will be a lot more difficult to implement > initially, but should ultimately provide both faster and safer metadata > updates, while simultaneously eliminating fsck delays during crash > recovery! At least that's how I read things. I'm still a newbie kernel > hacker, after all... Comments? > Our breakage of the BSD-LFS code isn't all that bad. I had it running pre-merged VM/Buffer Cache, and it was kind-of unstable, but very fast to say the least. ANYONE who is going to make a bona-fide attempt to get it working with FreeBSD will get alot of my hacking time for help. It is missing an LFSCK, and contrary to what alot of people might say, IMO it is needed. That is likely where most of the work would be. My guess is that just getting LFS running sort-of reliably would be 2wks+- full time of work, if you understand things to begin with. It is not a night or two of work, but probably not a couple of months full time either. There are some patches from Margot (I am not sure if we have integrated them), and also some VM system work (to eliminate alot of usually unnecessary copies). If someone will take the project on, and get the code running as-is, I will do the work to clean up the VM stuff (and help with working the kernel VM/vfs_bio interface issues.) Jeffery Hsu is working on the VFS stuff right now, so I would suggest waiting until his stuff settles out (or at least track it), but alot of prelim work could start immediately. So, I guess what I am saying is that if someone will take the lead, I'll help!!! John