[oe] Kernel Headers Quality Issue (was: linux vs. linux-libc-headers?)

[Tom Rini]

On Mon, 2010-05-10 at 16:53 +0200, Thilo Fromm wrote:
> Hello Guys,
> 
> this is a somewhat cumulated response - I'd like to address some of the 
> things mentioned at different points in the discussion in one place. 
> Please forgive me should I misquote things.
> 
> 
> 
> Graeme Gregory in <20100505094242.GF2444 at xora-desktop.xora.org.uk>:
> 
> [Steffen Sledz]
>  > > It seem's not to be possible to use DEFAULT_PREFERENCE_hipox in the
>  > > linux-libc-headers recipes. So what's the right way to handle this?
>  > > Something like PREFERRED_VERSION_linux-libc-headers_hipox = "2.6.24"
>  > > in angstrom-2008.1.conf?
>  >
> [Graeme Gregory]
>  > I thought glibc was supposed to gracefully fall back on missing
>  > syscalls?
> 
> Glibc is compiled against 2.6.31 headers, which is one of our main 
> issues here. It only ever *runs* with a 2.6.24 kernel on the target 
> system, though. So it cannot know about missing syscalls until runtime.

Looking at it again and based on what Khem said (and re-reading your
failures), the problem is not with glibc, but with other programs (glib,
udev are both mentioned specifically) and these programs specifically
not failing gracefully.  For example, it's quoted over in:
http://lists.linuxtogo.org/pipermail/openembedded-devel/2010-May/019626.html
that glib falls way back.  I think Phil was wrong here and without
checking the code, I imagine glib is trying fancy newer syscall,
failing, and then falling far back, rather than to just inotify_init as
you expected.  So the bug here is with glib.

As for the udev issue, I do not know how they will react to making the
udev version be soft-assign as that too may raise issues.  And iirc,
udev is or at least can be more tied to min kernel versions.

-- 
Tom Rini <tom_rini at mentor.com>
Mentor Graphics Corporation