From owner-freebsd-hackers@FreeBSD.ORG Tue Apr 9 00:35:10 2013 Return-Path: Delivered-To: freebsd-hackers@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:1900:2254:206a::19:1]) by hub.freebsd.org (Postfix) with ESMTP id 91258B53; Tue, 9 Apr 2013 00:35:10 +0000 (UTC) (envelope-from bright@mu.org) Received: from elvis.mu.org (elvis.mu.org [192.203.228.196]) by mx1.freebsd.org (Postfix) with ESMTP id 80D4A666; Tue, 9 Apr 2013 00:35:10 +0000 (UTC) Received: from Alfreds-MacBook-Pro-9.local (c-67-180-208-218.hsd1.ca.comcast.net [67.180.208.218]) by elvis.mu.org (Postfix) with ESMTPSA id AFFD51A3C19; Mon, 8 Apr 2013 17:35:04 -0700 (PDT) Message-ID: <5163622F.60604@mu.org> Date: Mon, 08 Apr 2013 17:34:55 -0700 From: Alfred Perlstein User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.7; rv:17.0) Gecko/20130328 Thunderbird/17.0.5 MIME-Version: 1.0 To: Adrian Chadd Subject: Re: GSOC 2013 project " Kernel Size Reduction for Embedded System " References: <20130408224423.GA64696@stack.nl> In-Reply-To: Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Cc: freebsd-hackers@freebsd.org, Amit Rawat , Jilles Tjoelker X-BeenThere: freebsd-hackers@freebsd.org X-Mailman-Version: 2.1.14 Precedence: list List-Id: Technical Discussions relating to FreeBSD List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 09 Apr 2013 00:35:10 -0000 On 4/8/13 4:10 PM, Adrian Chadd wrote: > Hi, > > Your idea is interesting, but it doesn't fix the underlying problem - > there's just too much code. :( > If you were to API'ify some of the more basic things such as fget, fdrop, filedesc stuff you could potentially swap out the systems for simpler (albeit less efficient) algorithms, the cost there may be slow smp performance, or maybe not allowing threads? What we really need is someone to pin down those parts of code that smaller systems may not need and provide compromise when we remove them. Other ideas are simple like for instance removing certain syscalls (for example, more recent ones such as openat) and features such as unix descriptor passing. However, until a bunch of embedded folks come forward and state what they are really willing to sacrifice, then we won't really have anything to go on, and it will be guessing at what will work for a space that not all of us are familiar with. So I'm hoping some people can make the tough call to give direction here, otherwise nothing good will come of it. Has anyone actually done this? Or maybe compared against another embedded OS? -Alfred