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diff --git a/community/gsoc/2012/virt/discussion.mdwn b/community/gsoc/2012/virt/discussion.mdwn new file mode 100644 index 00000000..31b9ce01 --- /dev/null +++ b/community/gsoc/2012/virt/discussion.mdwn @@ -0,0 +1,216 @@ +[[!meta copyright="Copyright © 2012 Free Software Foundation, Inc."]] + +[[!meta license="""[[!toggle id="license" text="GFDL 1.2+"]][[!toggleable +id="license" text="Permission is granted to copy, distribute and/or modify this +document under the terms of the GNU Free Documentation License, Version 1.2 or +any later version published by the Free Software Foundation; with no Invariant +Sections, no Front-Cover Texts, and no Back-Cover Texts. A copy of the license +is included in the section entitled [[GNU Free Documentation +License|/fdl]]."]]"""]] + + +# IRC, freenode, #hurd, 2012-07-19 + + <nowhere_man> well, I really actively started last week, so I'm ironing my + various use cases and above all I'm taking my barings in Hurd's code + <nowhere_man> I'm currently reading boot/ and pfinet/ + <braunr> sorry for asking but + <braunr> can you describe brielfy what you mean to achieve + <braunr> i know it sounds weird but the project description is a bit vague + for me + <nowhere_man> OK + <nowhere_man> the main goal is to be able to easily spawn a subhurd that's + connected in some way to its host + <braunr> ok + <nowhere_man> mainly connected by network, possibly sharing resources like + FS + <braunr> is it similar in spirit with something like linux containers ? + <nowhere_man> IIRC about them, yes + <braunr> ok + <braunr> that will do for me then + <tschwinge> Yes, so not complete virtualization, but instaed limitied to + several components. + <braunr> lxc with more runtime features to increase/decrease the level of + isolation + <nowhere_man> at first it would be static, at creation time only + <braunr> ok, i clearly understand the proposal now :) + <braunr> what kind of help could you need in the near future ? + <braunr> (except permanent access to youpi's brain?) + <tschwinge> Yes, that's my question, too -- what can we do to "get this + thing going". + <nowhere_man> by monday or tuesday I should be clear on what I understand + or not in the code + <nowhere_man> I'm still a bit up to my elbows in it + <nowhere_man> at that point I'll be happy to be able to pop a lot of + questions about it + <braunr> so you'll be ready for the next meeting + <nowhere_man> yeah + <tschwinge> Please do as soon as there are questions that you cannot + resolve in a reasonably short amount of time. + <tschwinge> So often a quick hint from someone else already helps to ge + un-stuck. + <nowhere_man> OK + <tschwinge> There is no problem with asking for help given this huge and + convoluted code-base, where often design decisions are not obvious, too. + <nowhere_man> I will + <tschwinge> Good. :-) + <antrik> nowhere_man: hm... what you said so far doesn't sound any + different than the work zhengda already did on boot years ago... + <antrik> (although none of it ever got upstream IIRC :-( ) + <nowhere_man> antrik: wasn't aware of it, is there some code published? + <tschwinge> There are bits and pieces, but certainly there is enough work + left to be done, to put it all together. + <antrik> yes, his git repository should be up somewhere. it's quite + convoluted though, as he worked on several things, and also wasn't very + experienced with revision control in the beginning + <tschwinge> nowhere_man: + http://www.gnu.org/software/hurd/community/gsoc/2008.html + <tschwinge> nowhere_man: http://www.gnu.org/software/hurd/user/zhengda.html + <tschwinge> Second section of the latter one. + <antrik> well, my understanding of the proposal (and more or less what I + was driving at in the project idea, which is rather vague admittedly) is + something lighter than a real subhurd... rather some kind of thin + subenvironment that doesn't actually boot a complete system instance with + various daemons etc. + <tschwinge> nowhere_man: It is certainly valid for you to use pre-existing + code/patches, by the way. + <antrik> BTW, regarding the "full subhurd" thing, the missing pieces are + mostly virtual device implementations + <antrik> (that and some tough bug(s) remaining in zhengda's modified + boot...) + <nowhere_man> cool, I'll take a look + <antrik> in any case, getting a picture of the work zhengda did is, is + definitely the first thing to do :-) + <tschwinge> nowhere_man: I'll also try to locate some bits and stuff from + his verious repositories (I just fond a Subverision one; will convert to + Git). + <antrik> tschwinge: I'm pretty sure zhengda's git repository was converted + from the SVN one... + <tschwinge> antrik: Thanks for reminding us about this -- I failed to + remember all that. + <antrik> (which was in turn converted from CVS...) + <tschwinge> antrik: OK, will have a lot. + <tschwinge> Yeah, found a CVS tree, too. ;-) + <antrik> BTW, zhengda's work more exactly was about subhurd without root + privileges. but that lays a lot of the groundwork for all kinds of more + flexible subhurd usage + <antrik> (but it's still quite a different thing that thing + subenvironments, so don't get confused...) + <antrik> err... thin subenvironments + + +# IRC, freenode, #hurd, 2012-07-27 + + <nowhere_man> bddebian: I'm actually not progressing much while reading the + source, I'm jumping all over the place to grasp the various types and + functions used where I start + <nowhere_man> would there be a few starting points that could help me? + <tschwinge> nowhere_man: So what exactly is your status; what are you + doing, what do you need help with? We surely can provide help, but need + to know where. + <nowhere_man> I'm starting from the source of boot/ and pfinet/ and as soon + as I encounter something that I don't understand, I find its definition + <nowhere_man> I'm kind of doing a depth-first search of what I need to + understand in the source code + <nowhere_man> I'm wondering if there are a few places in the source code + that I should start reading before anything else + <nowhere_man> well, I'll have to go in a few minutes + <nowhere_man> I'll continue my DFS ;-) + + +# IRC, freenode, #hurd, 2012-08-02 + + <nowhereman> well, I made a leap forward in understanding the code, when I + stopped my DFS + <nowhereman> in hindsight, I'd say my way of approaching the code was + probably one of the worst possible + <braunr> oh + <tschwinge> OK, so at least you learned something, which is good. + <tschwinge> So, what's the new approach? And what are you working on at + the moment + <tschwinge> ? + <nowhereman> I just remembered SICP, the idea of wishful thinking when you + code, and didn't bother with the fine details behind what I'm reading + <nowhereman> like, I don't really get what happens when a Mach port is + allocated, but I know approximately what a Mach port is + <tschwinge> So originally you worked on investigating all that, every line + of code? + <nowhereman> almost, yeah + <braunr> nowhereman: again, feel free to ask + <tschwinge> Yes indeed -- that's too complex for a single person to tackle + at one time. + <braunr> and quickly + <braunr> don't loose time + <tschwinge> Not even braunr and I have looked up all these things. + (Speaking for Richard here, but I'm quite sure he'll agree. Perhaps he + has in fact looked up all the Mach things, though.) + <tschwinge> nowhereman: ufc? + <nowhereman> BTW, last week I wanted to push my description of how the tool + could be used, the use cases + <nowhereman> ufs + <nowhereman> but flubber is not online + <tschwinge> nowhereman: Oh, why ufs specifically? + <braunr> don't waste time on ufs + <braunr> really + <tschwinge> nowhereman: Yes, flubber is down. But you can push directly to + the Savannah repository. + <tschwinge> nowhereman: Please immediatelly tell us if you're stuck on + something, like flubber not being available. + <tschwinge> We may not be able to help immediatelly, but we're the at least + aware of issues. + <braunr> and we may be able to help immediately :) + <tschwinge> As we're not sitting in a lab next to each other, we can't tell + otherwise what's going on. + <tschwinge> We may in fact even be able to tell you immediatelly to use + Savannah instead of flubber, indeed. + <tschwinge> nowhereman: So, back to ufs -- which you don't specifically + need to look at, I think -- ext2fs is what everyone uses. But even there + you shouldn't really need to know many details/internals. + <nowhereman> OK, I was looking into it has it appears in hurd.boot + <tschwinge> Ah, OK. Yeah, that's just an example/template, and should use + ext2fs nowadays. + <nowhereman> in fact, as far as FS are concerned, I suppose I will merely + need to know how to pass a port to the host's FS to some proxy FS in the + subhurd + <nowhereman> mmmh, Savannah only mentions a hurd.git + <tschwinge> Exactly that is the abstraction level you need, yes. + <nowhereman> I'm looking at http://savannah.gnu.org/git/?group=hurd + <tschwinge> Yeah, that's a known shortcoming -- look here instead: + http://git.savannah.gnu.org/cgit/hurd + <tschwinge> Here is some more up-to-date stuff on subhurds: + http://www.gnu.org/software/hurd/hurd/subhurd.html + <tschwinge> nowhereman: You know how to tell git to add a new remote to + your web pages checkout and such stuff? + <nowhereman> yeah, no problem with that + <braunr> have you prepared any question to ask us ? + <nowhereman> the only I have now is if you can tell me where to look in the + code about passing Mach ports + <braunr> you don't pass ports, you pass rights + <braunr> http://www.gnu.org/software/hurd/gnumach-doc/index.html is the + best location to have a look at + <braunr> + http://www.gnu.org/software/hurd/gnumach-doc/Exchanging-Port-Rights.html#Exchanging-Port-Rights + <braunr> i suppose the mig doc will help too, as you may be using a higher + level interface to exchange rights + <braunr> be careful about user references on port rights + <braunr> deallocate releases a reference, it doesn't immediately destroy a + resource + <braunr> portinfo -v can help monitoring a task's rights + <braunr> nowhereman: so what are you planning to do now ? + <braunr> during the next week + <nowhereman> documenting what I understand from the boot process and where + things can be changed to fit my various use cases + <braunr> do you expect that to take the whole week ? + <nowhereman> and doing some first modifications to servers for the simplest + cases + <braunr> ok + <braunr> well i hope you're able to really start working on it soon, and + won't face weird issues in the meantime + <braunr> i'm a bit disappointed that you don't have more questions + <braunr> my feeling is you either did understand everything (except passing + port rights), or you didn't attempt to seriously understand the code + <braunr> or you don't dare ask questions + <braunr> this is something that must change + <braunr> or these meetings won't be as useful as they could be + <tschwinge> Yes. But also please don't wait for the meetings, but ask + questions throughout the week, too. |