Re: [PATCH 2.6.12-rc1-mm1 3/3] perfctr: 64-bit values in register descriptors

[Stephen Rothwell <sfr@canb.auug.org.au>]

On Wed, 23 Mar 2005 04:00:03 +0100 (MET) Mikael Pettersson <mikpe@csd.uu.se> wrote:
>
> diff -rupN linux-2.6.12-rc1-mm1/include/linux/perfctr.h linux-2.6.12-rc1-mm1.perfctr-update-common/include/linux/perfctr.h
> --- linux-2.6.12-rc1-mm1/include/linux/perfctr.h	2005-03-22 21:59:08.000000000 +0100
> +++ linux-2.6.12-rc1-mm1.perfctr-update-common/include/linux/perfctr.h	2005-03-23 02:19:45.000000000 +0100
> @@ -27,10 +27,10 @@ struct vperfctr_control {
>  #define VPERFCTR_CONTROL_RESUME		0x03
>  #define VPERFCTR_CONTROL_CLEAR		0x04
>  
> -/* common description of an arch-specific 32-bit control register */
> +/* common description of an arch-specific control register */
>  struct perfctr_cpu_reg {
>  	__u32 nr;
> -	__u32 value;
> +	__u64 value;
>  };

I don't know if you support 32 bit binaries on x86_64, but if you do (or
intend to), then this structure will need translating.  The x86 compiler
aligns 64 bit quantities on 32 bit boundaries (as far as I am aware)
whereas (I am pretty sure) the x86_64 compiler aligns them to 64 bit
boundaries. This is fine for ppc/ppc64 as both align 64bit quantities on
64 bit boundaries.

-- 
Cheers,
Stephen Rothwell                    sfr@canb.auug.org.au
http://www.canb.auug.org.au/~sfr/

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