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# 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.