Subject: Re: [PATCH] x86 (Linux Tiny): configure out support for
	some	processors
From: Simon Holm =?ISO-8859-1?Q?Th=F8gersen?= <odie@cs.aau.dk>
To: Michael Opdenacker <michael-lists@free-electrons.com>
Cc: Matt Mackall <mpm@selenic.com>, Andrew Morton <akpm@linux-foundation.org>,
       Ingo Molnar <mingo@elte.hu>, Thomas Gleixner <tglx@linutronix.de>,
       "H. Anvin" <hpa@zytor.com>, linux-kernel@vger.kernel.org,
       Linux-tiny@selenic.com
In-Reply-To: <47AD725E.6050903@free-electrons.com>
References: <200802082347.25364.michael-lists@free-electrons.com>
	 <1202512812.17934.680.camel@cinder.waste.org>
	 <1202545817.6722.24.camel@odie.local> <47AD725E.6050903@free-electrons.com>
Content-Type: text/plain; charset=utf-8
Date: Sat, 09 Feb 2008 11:05:43 +0100
Message-Id: <1202551543.6722.38.camel@odie.local>
Mime-Version: 1.0
Content-Transfer-Encoding: 8bit
Sender: linux-kernel-owner@vger.kernel.org
Content-Length: 2339
Lines: 52


lør, 09 02 2008 kl. 10:29 +0100, skrev Michael Opdenacker:
> On 02/09/2008 09:30 AM, Simon Holm Thøgersen wrote:
> > 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.
> >   
> Thanks for this report. Don't you think it's still useful to save up to
> 12 K of code that you don't use if you just have an Intel processor (for
> example)?

The last remark was only about the code changes in
arch/x86/kernel/cpu/common.c, arch/x86/kernel/process_32.c,
arch/x86/kernel/process_64.c and arch/x86/mm/init_32.c, which my report
didn't reflect upon since I never applied the patch. The ~12kB reduction
no doubt has a good gain/pain ratio.

Out of curiosity, how small a kernel are you targeting this work for? I
guess your other post on 'make allnoconfig + CONFIG_EMBEDDED' has
disabled more stuff than you would use in practice?


Simon

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