[Cbe-oss-dev] [PATCH] Make PS3_SYS_MANAGER default y, not m

[Michael Ellerman]

On Sun, 2007-12-09 at 22:26 -0800, Geoff Levand wrote: 
> Hi Michael,
> 
> On 12/09/2007 08:17 PM, Michael Ellerman wrote:
> > Currently it's impossible to build a ps3_defconfig which will reboot
> > without modules installed. This makes it all too easy to find yourself
> > with a PS3 that won't reboot.
> > 
> > This is because the system manager driver, which provides the reboot
> > mechanism, is only selectable if PS3_ADVANCED is set, else it defaults
> > to m. In ps3_defconfig PS3_ADVANCED is not set, therefore the system
> > manager is built as a module.
> > 
> > It would be desirable IMHO for the defconfig to produce a kernel that
> > boots and reboots, without needing modules to be installed.
> 
> Sorry, I will say NACK at this point in time.
> 
> I think it is just user error not to install the modules along with
> the new kernel.  If the user's environment is such that this doesn't
> happen with INSTALL_MOD_PATH and make modules_install, then a user
> script should be made that does whatever extra is needed to get them
> installed.

Oh ok. Then instead of the cute penguins we show our users at boot, how
about we change it to something more in line with how we're treating
them:

http://en.wikipedia.org/wiki/Image:Thefinger.jpg

> I'm thinking to make as much of the ps3 kernel as possible built as
> modules by default.  My reasoning is two fold.  The first is that
> many bugs seem to stem from modular drivers, and having them built
> in the def config exposes them early.  The other is that now we have
> sparsemem vmmemmap the 128 MiB of boot mem is getting too fragmented
> (see http://lkml.org/lkml/2007/12/3/137) and reducing the kernel
> image size will ease this.

Fine. But making the reboot logic a module is completely insane. If
anything goes wrong during boot before you find your root filesystem you
end up with a brick. And it's not like that's never happened, 
/dev/sda .. /dev/ps3da anyone?

If memory pressure is an issue perhaps we need to look at the amount of
code required to do a reboot, if it's really that enormous perhaps there
needs to be a minimal stub version or something.

cheers

-- 
Michael Ellerman
OzLabs, IBM Australia Development Lab

wwweb: http://michael.ellerman.id.au
phone: +61 2 6212 1183 (tie line 70 21183)

We do not inherit the earth from our ancestors,
we borrow it from our children. - S.M.A.R.T Person
-------------- next part --------------
A non-text attachment was scrubbed...
Name: not available
Type: application/pgp-signature
Size: 189 bytes
Desc: This is a digitally signed message part
URL: <http://lists.ozlabs.org/pipermail/cbe-oss-dev/attachments/20071211/16672eaa/attachment.pgp>