* Adrian Bunk <bunk@kernel.org> wrote:

> > What i do against build breakage is randconfig testing. That catches 
> > far more build breakage than a few limited number of defconfigs 
> > would ever.
> 
> How do you test whether a x86 merge might break the compilation of 
> e.g. some ARM platform without using any defconfig?

yes, we do test that too. (we added this recently)

> And building all defconfigs is the trivial way of having most 
> reasonable configurations covered with only one day of compile time.

the existing 32-bit and 64-bit defconfigs should be enough for that. For 
better/full coverage, randconfig should be used.

> > More defconfigs would just be a constant maintenance drag, they are 
> > rather pointless on PC hardware anyway (we'd have to have at least a 
> > few hundred of them for it to be meaningful as a "default config") 
> > and it does not really solve the problem either.
> 
> My goal was "one per subarchitecture" which is not such a big number.

at least on x86 subarchitectures are not at all that important (they are 
a rather inflexible build-time concept), and as you have seen it in this 
thread, we are working on reducing their count. 99% of the real hardware 
is covered under the generic subarchitecture.

they are more important on other (mostly embedded) platforms, with ARM 
having 75 defconfigs.

	Ingo