Subject: Re: [PATCH] Make u64 long long on all architectures (was: the printk problem)

From: Andrew Morton <[email-masked]>
Date: Tue, 22 Jul 2008 03:05:06 -0700

On Fri, 4 Jul 2008 20:03:51 -0600 Matthew Wilcox <[email-masked]> wrote:

> [PATCH] Make u64 long long on all architectures
> 
> It is currently awkward to print a u64 type.  Some architectures use
> unsigned long while others use unsigned long long.  Since unsigned long
> long is 64-bit for all existing Linux architectures, change those that
> use long to use long long.  Note that this applies only within the
> kernel.  If u64 is being used in a C++ method definition, the symbol
> mangling would change.
> 
> Signed-off-by: Matthew Wilcox <[email-masked]>
> 
> diff --git a/include/asm-generic/int-l64.h b/include/asm-generic/int-l64.h
> index 2af9b75..32f07bd 100644
> --- a/include/asm-generic/int-l64.h
> +++ b/include/asm-generic/int-l64.h
> @@ -23,8 +23,13 @@ typedef unsigned short __u16;
>  typedef __signed__ int __s32;
>  typedef unsigned int __u32;
>  
> +#ifdef __KERNEL__
> +typedef __signed__ long long __s64;
> +typedef unsigned long long __u64;
> +#else
>  typedef __signed__ long __s64;
>  typedef unsigned long __u64;
> +#endif
>  
>  #endif /* __ASSEMBLY__ */

This is (IMO) a desirable change and will prevent a heck of a lot of
goofing around, and will permit a lot of prior goofing around to
be removed.

But I bet there are lots of instalces of printk("%l", some_u64) down in
arch code where the type of u64 _is_ known which will now spew warnings.

Oh well.