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[[!tag open_issue_documentation]]
What are the benefits of a native GNU/Hurd system, now that Linux et al. can do
so much (think [[hurd/translator]]s: FUSE, [[hurd/subhurd]]s: User-Mode-Linux,
etc.).
It is possible to begin [[implementing_Hurd_on_top_of_another_system]], but...
IRC, #hurd, August / September 2010
<marcusb> ArneBab: but Neal and I were not happy with that alone. We were
looking for deeper improvements to the system, for, I think, sound reasons.
That is what brought us to the L4/Coyotos technologies
<marcusb> ArneBab: as you are writing a kernel in user space, you can still do
kernel improvements there
<marcusb> ArneBab: if you take it very far, you end up with a kernel that runs
Linux in user space (just flip the two) for the drivers
<marcusb> ArneBab: that is what the L4 people did with the DDE
([[DDE]])
<marcusb> ArneBab: so, with these different cuts, there are different
opportunities. on the one end, you can run Linux as normal and get some of
the Hurd features such as translators in some programs. At the other end,
you can do whatever you want and run some linux code for the drivers or none
at all.
<marcusb> ArneBab: one of the big questions then becomes: at which point can
the advantages offered by the Hurd be realized?
<marcusb> ArneBab: and that's not entirely clear to me
<marcusb> when I worked on this with Neal, we pushed further and further into
need-to-change-everything land
<marcusb> while the current efforts on the Hurd seem to be more equivalent to
the could-run-it-in-userspace-on-top-of-Linux camp
<ArneBab> marcusb: for that I think we need a way to move towards them step by
step. Would it be possible to get the advantages of better resource
allocation with a Viengoos in userspace, too?
<ArneBab> and when that is stable, just switch over?
<marcusb> ArneBab: I don't know. I suspect these people will know before us:
http://lxc.sourceforge.net/
<ArneBab> something like implementing flip points: flip Linux with Hurd to Hund
with Linux. Flip Mach with L4 to L4 with Mach.
<ArneBab> lxc sounds interesting.
<marcusb> note that these efforts address security concerns more than other
concerns
<marcusb> so they will get isolation long before sharing is even considered
<marcusb> but some of the issues are the same
<marcusb> once you allow malware to do what it wants, it's a small step to also
allow the user to what he wants :)
<ArneBab> it kinda looks like hacking it where it doesn’t really fit again…
<ArneBab> there I ask myself when the point comes that doing a cleaner design
offsets the popularity
<ArneBab> they are pushing more and more stuff into userspace
<ArneBab> which is a good thing (to me)
<ArneBab> it’s hard to clearly describe how, but even though I like having more
stuff in userspace, the way it is bolted onto Linux doesn’t feel good for me.
<ArneBab> FUSE is cool, but if I use it, I am at a disadvantage compared to a
non-fuse user
<ArneBab> while in the Hurd, these additional options are on eqal footing.
<marcusb> ArneBab: are they pushing more and more into user space? I don't
think so. I see more of the reverse, actually
<marcusb> or maybe both
<ArneBab> FUSE, lxd and scheduling in userspace move to userspace
<ArneBab> well, KMS moved to the kernel
<ArneBab> to avoid flickering when switching between X and the console?
<ArneBab> marcusb: Do you experience FUSE lxc and such being secondclass in
Linux, too, or is that just a strange feeling of me?
<ArneBab> marcusb: and that splits the users into those who can get stuff into
the kernel and those who can only work in userspace – which I don’t really
like.
<ArneBab> That’s one more advantage of the Hurd: eqal footing for all (except
the Mach hackers, but they have a very limited terrain)
<marcusb> ArneBab: but UML kernel module is minimal, and Linus didn't have a
principled objection to it (but just wanted a more general solution)
<marcusb> ArneBab: as a side note, although people keep complaining, the linux
kernel seems to be growing steadily, so getting stuff into the kernel doesn't
seem too hard. 8-O
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