Re: [PATCH 0/4] Compile kernel with -fwhole-program --combine

From: Adrian Bunk
Date: Thu Aug 24 2006 - 17:46:36 EST


On Thu, Aug 24, 2006 at 04:24:28PM +0100, David Woodhouse wrote:
>...
> Using a combination of these two compiler options for building kernel
> code leads to some useful optimisation -- especially with modules which
> are made up of a bunch of incestuous C files, where none of the global
> symbols actually _need_ to be visible outside the directory they reside
> in. File systems are a prime example of this -- on PPC64 I see a
> reduction in size of ext3.ko by 2.6%, jffs2.ko by 5%, cifs.ko by 8% and
> befs.ko by a scary 14%. Strangely, udf.ko seems to have _grown_ by 6.6%
> -- that'll probably be another optimisation bug like GCC PR28755.
>...

Looks good. :-)

What kernel are your patches against?

2.6.18-rc4 gives me:

<-- snip -->

...
CHK include/linux/version.h
CHK include/linux/utsrelease.h
CC arch/i386/kernel/asm-offsets.s
GEN include/asm-i386/asm-offsets.h
HOSTCC scripts/kallsyms
HOSTCC scripts/conmakehash
HOSTCC scripts/bin2c
make[1]: *** No rule to make target `/home/bunk/linux/linux-2.6.18-rc4/dummy.c', needed by `init/init.o'. Stop.
make: *** [init] Error 2

<-- snip -->

> dwmw2

cu
Adrian

--

Gentoo kernels are 42 times more popular than SUSE kernels among
KLive users (a service by SUSE contractor Andrea Arcangeli that
gathers data about kernels from many users worldwide).

There are three kinds of lies: Lies, Damn Lies, and Statistics.
Benjamin Disraeli

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