[PATCH v3 2/3] ARM: vmlinux.lds.S: align the exception fixup table to a 4-byte boundary

[Nicolas Pitre]

On Tue, 17 Jan 2012, Will Deacon wrote:

> The exception fixup table is currently aligned to a 32-byte boundary.
> Whilst this won't cause any problems, the exception_table_entry
> structures contain only a pair of unsigned longs, so 4-byte alignment
> is all that is required.

If the table was also walked from start to end, that could also be an 
argument for aligning it to a cache line so the first access always 
fetches a whole cache line worth of usable data.  But the access is done 
through a binary search which is totally random as far as access pattern 
goes.  That would be worth mentioning in the commit log.

With that:

Acked-by: Nicolas Pitre <nico at linaro.org>

> Cc: Nicolas Pitre <nico at fluxnic.net>
> Signed-off-by: Will Deacon <will.deacon at arm.com>
> ---
>  arch/arm/kernel/vmlinux.lds.S |    2 +-
>  1 files changed, 1 insertions(+), 1 deletions(-)
> 
> diff --git a/arch/arm/kernel/vmlinux.lds.S b/arch/arm/kernel/vmlinux.lds.S
> index 1077e4f..1e19691 100644
> --- a/arch/arm/kernel/vmlinux.lds.S
> +++ b/arch/arm/kernel/vmlinux.lds.S
> @@ -219,7 +219,7 @@ SECTIONS
>  		/*
>  		 * The exception fixup table (might need resorting at runtime)
>  		 */
> -		. = ALIGN(32);
> +		. = ALIGN(4);
>  		__start___ex_table = .;
>  #ifdef CONFIG_MMU
>  		*(__ex_table)
> -- 
> 1.7.4.1
>