Re: [PATCH] Load FCP modules early for CD/DVD install (#184648)

[Jeremy Katz <katzj redhat com>]

On Tue, 2008-12-02 at 07:52 -1000, David Cantrell wrote:
> Jeremy Katz wrote:
> > On Mon, 2008-12-01 at 12:03 -1000, David Cantrell wrote:
> >> Load the SCSI modules earlier for CD/DVD installs on s390.  Also,
> >> always set up the network interface because you still need that
> >> to ssh in and run loader.
> > 
> > There's nothing that seems out of place here in a quick look given the
> > surrounding aspect of linuxrc.s390.  Has it been tested in the context
> > of something more rawhide-ish?  Things like insmod instead of modprobe
> > jump out at me as potentially problematic.  I'm going to have to say I
> > have no clue where the Fedora on s390 efforts stand these days.
> 
> Tested on rawhide?  No.  Tested on rhel5?  Yes.  These patches are meant
> to bring the master branch in line with rhel5-branch.  IBM did a lot of
> contributions to linuxrc.s390 for 5.3.
> 
> Fedora on s390 is progressing, but slowly.  There is an F-9 build now
> and koji set up, but things are not quite there yet for regular
> development.  In the mean time, IBM and myself have been doing
> development on the 5.3 nightlies.  Things are getting closer though.

Okay, sounds sane.  I know that your intention was largely syncing, I
just wasn't sure how much/if any testing was doable right now.  Given
that it's s390, lack of testing doesn't imply that we shouldn't get
things synced :)

> > But taking a step back to some more general thoughts on linuxrc.s390, is
> > there an effort to actually get it using the same things we use
> > everywhere else?  There's a lot of manual module probing instead of
> > letting things be done by udev and then manual network configuration
> > instead of using NetworkManager.  As we've moved more of these bits to
> > be common, we really probably need to sit down and rework the entire way
> > that the script works.  The goal of it is that it takes the place of
> > loader/init.c with a few notable and important differences
> > * Prompting for information on things like network setup if you don't
> > set it in the parm file.  This pretty much has to be "custom" for s390
> > and doing it with shell is as easy as anything else
> > * Getting modules loaded.  We don't do this until in the loader on other
> > arches, but we need to do it to get the network up.  But we really
> > probably want to let udev do it as much as we can
> > * Starting the network.  Which we do with spawning NetworkManager in the
> > "normal" case
> 
> This mirrors a conversation I've had with IBM recently.  Personally, I'd
> like linuxrc.s390 to go entirely.  It's a maintenance nightmare and
> init.c can just grow to include s390 code where needed.  Not only is
> there a different init for the s390 initrd, the initrd itself is
> significantly different from the other architectures.

Yep.  And now that we've bit the bullet and accept a "larger" initrd for
most cases, there are people that would actually really like the ssh
functionality that we have on s390.

> IBM is very interested in reworking the linuxrc.s390 system as well.
> For 5.x, they have a nice rewrite that improves the input loops and
> module loading.  For rawhide, I am at least wanting to get away from
> having linuxrc.s390 at all.  Even if we keep the linuxrc.s390 script,
> reducing it to bare minimum and turning things over to the real init
> when we are done are better than what we have now.  s390 is such a
> special case anyway though, it'll take some more planning.
> 
> Right now, I am happy with IBM improving the init system we have now.
> They are far more knowledgeable about their platform than I am.

100% agreed, and to be honest, that was kind of what I was getting at
without wanting to explicitly call them out and say "hey, come to the
party and let's work to make this suck less" :)

Jeremy