[PATCH v2 4/4] powerpc: Allow LD_DEAD_CODE_DATA_ELIMINATION to be selected

[Michael Ellerman]

Nicholas Piggin <npiggin at gmail.com> writes:

> This requires further changes to linker script to KEEP some tables
> and wildcard compiler generated sections into the right place. This
> includes pp32 modifications from Christophe Leroy.
>
> When compiling powernv_defconfig with this option, the resulting
> kernel is almost 400kB smaller (and still boots):
>
>     text      data       bss        dec   filename
> 11827621   4810490   1341080   17979191   vmlinux
> 11752437   4598858   1338776   17690071   vmlinux.dcde
>
> Mathieu's numbers for custom Mac Mini G4 config has almost 200kB
> saving. It also had some increase in vmlinux size for as-yet
> unknown reasons.
>
>     text      data       bss        dec   filename
>  7461457   2475122   1428064   11364643   vmlinux
>  7386425   2364370   1425432   11176227   vmlinux.dcde
>
> Tested-by: Christophe Leroy <christophe.leroy at c-s.fr> [8xx]
> Tested-by: Mathieu Malaterre <malat at debian.org> [32-bit powermac]
> Signed-off-by: Nicholas Piggin <npiggin at gmail.com>
> ---
>  arch/powerpc/Kconfig              |  1 +
>  arch/powerpc/kernel/vmlinux.lds.S | 22 +++++++++++-----------
>  2 files changed, 12 insertions(+), 11 deletions(-)

I'm happy for this to go in via the kbuild tree.

As long as it's in linux-next it will get tested by my CI which should
hopefully shake out any bugs.

Acked-by: Michael Ellerman <mpe at ellerman.id.au>

cheers