Re: [PATCH] x86 (Linux Tiny): configure out support for some processors

["Simon Holm Thøgersen" <odie@cs.aau.dk>]

fre, 08 02 2008 kl. 17:20 -0600, skrev Matt Mackall:
> On Fri, 2008-02-08 at 23:47 +0100, Michael Opdenacker wrote:
> > This patch against x86/mm tries to revive an original patch
> > from Matt Mackall which didn't get merged at that time. It makes
> > it possible to disable support code for some processors. This can
> > be useful to support only the exact processor type used
> > in a given system.
> > 
> > I may have made wrong assumptions with the code handling
> > force_mwait. As force_mwait is only declared in
> > arch/x86/kernel/cpu/amd.c, which is only compiled
> > when CONFIG_X86_32 is set, I thought it was safe
> > to make the code depend on CONFIG_CPU_SUP_AMD,
> > but I could be wrong.
> > 
> > Your comments are more than welcome! To make the code
> > cleaner, I could use empty inline functions instead
> > of ifdef's, as suggested in Documentation/SubmittingPatches.
> 
> Please include the output of size with all these options on and off.

The build of my currently running kernel for my laptop has
$ size -t amd.o cyrix.o centaur.o transmeta.o intel.o nexgen.o umc.o
   text	   data	    bss	    dec	    hex	filename
   2809	    316	      0	   3125	    c35	amd.o
   2387	    856	      0	   3243	    cab	cyrix.o
   1514	    312	      0	   1826	    722	centaur.o
   1279	    312	      0	   1591	    637	transmeta.o
   1783	    316	      0	   2099	    833	intel.o
    126	    312	      0	    438	    1b6	nexgen.o
     41	    312	      0	    353	    161	umc.o
   9939	   2736	      0	  12675	   3183	(TOTALS)

That is without optimize for size compilation, with that set I get
$ size -t amd.o cyrix.o centaur.o transmeta.o intel.o nexgen.o umc.o
   text	   data	    bss	    dec	    hex	filename
   2300	    316	      0	   2616	    a38	amd.o
   2132	    820	      0	   2952	    b88	cyrix.o
   1325	    312	      0	   1637	    665	centaur.o
   1151	    312	      0	   1463	    5b7	transmeta.o
   1575	    316	      0	   1891	    763	intel.o
    107	    312	      0	    419	    1a3	nexgen.o
     41	    312	      0	    353	    161	umc.o
   8631	   2700	      0	  11331	   2c43	(TOTALS)

I don't think the code changes in the patch do much with respect to
size.


Simon Holm Thøgersen