Re: current BK compilation failure on ppc32

[Linus Torvalds]

On Sat, 3 Jul 2004, Christoph Hellwig wrote:
> 
> kernel/power/smp.c seems to be inherently swsusp-specific but is
> compiled for CONFIG_PM. (Same seems to be true for amny other files
> in kernel/power/, but as they compile it only causes bloat..)
> 
> 
> --- 1.10/kernel/power/Makefile	2004-07-02 07:23:47 +02:00
> +++ edited/kernel/power/Makefile	2004-07-03 22:07:29 +02:00
> @@ -1,5 +1,7 @@
>  obj-y				:= main.o process.o console.o pm.o
> +ifeq ($(CONFIG_SOFTWARE_SUSPEND), y)
>  obj-$(CONFIG_SMP)		+= smp.o
> +endif

Don't do it like that.

Instead, do something like

	smp-power-$(CONFIG_SMP)	+= smp.o
	obj-$(CONFIG_SOFTWARE_SUSPEND) += $(smp-power-y)

which not only is shorter, but gets a _lot_ more readable after a while.

It's also extremely useful for constructs like "include this file X is
either 'y' or 'm'". From fs/Makefile:

	..

	nfsd-$(CONFIG_NFSD)             := nfsctl.o
	obj-y                           += $(nfsd-y) $(nfsd-m)

	..

which just means that "nfsctl.o" will be compiled in if nfsd is 
compiled-in or a module.

You can make pretty complex decision trees this way - much more readably 
than by explicit comparisons.

		Linus
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