Re: [PATCH] Add rdc321x defconfig file

From: Adrian Bunk
Date: Mon Feb 25 2008 - 06:10:09 EST


On Mon, Feb 25, 2008 at 11:14:33AM +0100, Ingo Molnar wrote:
>
> * Florian Fainelli <florian.fainelli@xxxxxxxxxxxxx> wrote:
>
> > This patch adds the default kernel configuration for the RDC R-321x
> > SoC.
>
> hm, i'm not sure. Right now we just have a 32-bit defconfig and a 64-bit
> defconfig - but there are about 8 subarchitectures in arch/x86. Given
> the amount of variety in PC hardware, i doubt it makes sense to start
> collecting defconfigs for hardware variants - we'd end up having
> hundreds or thousands of them. Even ARM has only 75 defconfigs.

What I want is at least one defconfig per subarchitecture for compile
tests.

And especially considering the original purpose "configuration users can
use as a starting point for configuring their kernel" I even wouldn't
mind if we had a few dozen x86 defconfigs.

> what i do is i regularly test whether "make allyesconfig" boots all the
> way up to general user-space in regular whitebox PC hardware. For
> example the attached config is such a config, i successfully booted it
> on 2.6.25-rc3 on a stock PC.

You are testing something completely different here.

What I want is that e.g. after fiddling with kernel headers I want an
easy way of having much compile coverage. And my script that builds all
defconfig's is trivial (although it takes a day to finish).

> This way we can ensure that the (near-) totality of the config space is
> bootable on regular PCs, and the subarch support is basically just
> bootstrap and quirks differences.

You miss our headers mess.

You remember how your big x86 merge this merge window broke 8 or 9 other
architectures? Change one file under include/ and watch how many
configurations no longer build.

Or other subtle differences between the subarchs that have in the past
led to compile errors.

I do consider them useful for the way I'm doing kernel tests, and even
if you don't consider them that useful can we agree that adding a
defconfig is neither a big deal for the subarchitecture maintainer nor
imposes any maintainance work on you as maintainer (except for sometimes
applying patches adding/updating them)?

> Longer term we should get rid of the
> subarchitecture distinction altogether and turn them into regular
> quirks/callbacks/drivers.
>...

Generally agreed (with my biggest worry being whether changing
CLOCK_TICK_RATE from a compile time constant to a runtime
variable has any performance effects).

> Ingo

cu
Adrian

--

"Is there not promise of rain?" Ling Tan asked suddenly out
of the darkness. There had been need of rain for many days.
"Only a promise," Lao Er said.
Pearl S. Buck - Dragon Seed

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/