Date: Wed, 1 Mar 2017 16:14:29 +0800 From: Julian Elischer <julian@freebsd.org> To: Warner Losh <imp@bsdimp.com>, Allan Jude <allanjude@freebsd.org> Cc: "freebsd-hackers@freebsd.org" <freebsd-hackers@freebsd.org>, Saurav Sachidanand <sauravsachidanand@gmail.com> Subject: Re: [GSoC 2017] Original proposal: Port kernel Lua to FreeBSD Message-ID: <f221e624-1342-7548-a3f9-806a1d25b90d@freebsd.org> In-Reply-To: <CANCZdfpiiJLyLbEQnk86mfwf07JGByq5oT_1-T43iEhscEEgMg@mail.gmail.com> References: <CACKq%2BiX_V2MY9sNf-buEOO1S87dbhDv%2BPGbUEqRUVkvzz3pdvw@mail.gmail.com> <244231A2-EB18-4E58-A2B2-927F55D54950@FreeBSD.org> <CANCZdfpiiJLyLbEQnk86mfwf07JGByq5oT_1-T43iEhscEEgMg@mail.gmail.com>
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On 28/2/17 2:01 am, Warner Losh wrote: > On Mon, Feb 27, 2017 at 8:26 AM, Allan Jude <allanjude@freebsd.org> wrote: >> On February 27, 2017 5:28:41 AM PST, Saurav Sachidanand <sauravsachidanand@gmail.com> wrote: >>> Hello FreeBSD community, >>> >>> I'm >>> Saurav Sachidanand, and I'm >>> a CS sophomore studying in India >>> . >>> I have an interest in operating systems development and wish to >>> contribute >>> to the FreeBSD community. I'm proficient with C and have some >>> experience in >>> kernel programming. Hence, I'd like to propose an original project for >>> GSoC >>> 2017 that I feel would benefit this community. >>> >>> In past years, the Lua interpreter was ported to run inside the Linux >>> and >>> NetBSD kernel [1]. Lua was chosen because it's interpreter is very >>> small (~240 >>> KB) compared to that of Python or Ruby, it's MIT licensed, and is >>> almost >>> freestanding. A working demonstration of it is a packet filtering >>> algorithm >>> written entirely in kernel Lua [2]. >>> >>> Specifically, my proposal would be to port the following that are >>> currently >>> written for NetBSD: >>> - the modified Lua VM source code with _KERNEL preprocessor directives >>> to >>> exclude user-space functionality like floating point, the io and os >>> module >>> in the standard library, etc. [3] >>> - the kernel module device driver for /dev/lua, to which Lua scripts >>> are >>> fed to be executed [4], [5] >>> - the luactl user-space program to control the Lua device and a couple >>> of >>> sysctl variables which serve similar purpose [6], [7] >>> >>> And then: >>> - run the Lua test suite targeting whatever we support in the kernel to >>> make sure it works [8] >>> - and write Lua bindings to the kernel interfaces that would interest >>> the >>> FreeBSD community >>> >>> Since NetBSD and FreeBSD have similar kernel interfaces (mutexes, >>> linked >>> lists, device switch interface), the porting shouldn't involve too much >>> code refactoring. Also, this would all be an experiment in that we >>> don't >>> fully know what the real world use cases might be, but it would attract >>> more people to writing kernel code who otherwise wouldn't because of >>> having >>> to do everything in C. And it would be interesting to carry out it out >>> in >>> FreeBSD as well since it has a larger community than NetBSD. >>> >>> I humbly request anyone who is interested in this project to be my >>> potential mentor(s) for GSoC. >>> >>> More slides on kernel Lua in NetBSD - [9], [10]. >>> >>> Thanks, >>> Saurav >>> >>> [1] - http://www.netbsd.org/~lneto/dls14.pdf >>> [2] - https://www.netbsd.org/~lneto/eurobsdcon14.pdf >>> [3] - https://github.com/jsonn/src/tree/trunk/external/mit/lua/dist/src >>> [4] - >>> https://github.com/IIJ-NetBSD/netbsd-src/tree/master/sys/modules/lua >>> [5] - >>> https://github.com/IIJ-NetBSD/netbsd-src/tree/master/sys/modules/luasystm >>> [6] - https://github.com/IIJ-NetBSD/netbsd-src/tree/master/sbin/luactl >>> [7] - http://netbsd.gw.com/cgi-bin/man-cgi?lua+4+NetBSD-current >>> [8] - http://www.lua.org/tests/ >>> [9] - >>> https://www.netbsd.org/gallery/presentations/mbalmer/fosdem2012/kernel_mode_lua.pdf >>> [10] - https://www.lua.org/wshop13/Cormack.pdf >>> _______________________________________________ >>> freebsd-hackers@freebsd.org mailing list >>> https://lists.freebsd.org/mailman/listinfo/freebsd-hackers >>> To unsubscribe, send any mail to >>> "freebsd-hackers-unsubscribe@freebsd.org" >> This may be quite a nice thing to have. Another upcoming use for LUA in the kernel is ZFS Channel Programs. These allow a number of ZFS operations to be completed as a single atomic transaction. >> >> I would hope we could structure this in such a way as to not end up with two copies of Lua in the kernel. > There's also a 3/4 finished lua in the boot loader that you might be > able to leverage as well.... I'd like to see that finished. While Devin has done Heroic work with the forth in the loader, I think it's time has come. It' be nice to have something a little less '60s. > > Warner > _______________________________________________ > freebsd-hackers@freebsd.org mailing list > https://lists.freebsd.org/mailman/listinfo/freebsd-hackers > To unsubscribe, send any mail to "freebsd-hackers-unsubscribe@freebsd.org" >
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