Re: kbuild 2.5 is ready for inclusion in the 2.5 kernel

[Paul Mackerras]

Keith Owens writes:

> Coding a special case to work out if the existing global makefile can
> be reused is horribly error prone.  And it would take just as long as
> rebuilding the global makefile from scratch.

I seriously doubt that last statement.  Building the global makefile
takes about 20 seconds on the box I compile on.  On a kernel tree
without object files I can read all the files in the kernel tree in
about 0.8 seconds, and I can calculate an md5sum of every file in 3.2
seconds.  I can do an md5sum of all the Makefile.in's in 0.1 seconds.
This is with pp_makefile* compiled with -O2 -DNDEBUG=1.

Paul.