Re: [RFC PATCH 02/33] Add sync bitops

From: Adrian Bunk
Date: Tue Jul 18 2006 - 06:32:12 EST


On Tue, Jul 18, 2006 at 12:00:02AM -0700, Chris Wright wrote:

> Add "always lock'd" implementations of set_bit, clear_bit and
> change_bit and the corresponding test_and_ functions. Also add
> "always lock'd" implementation of cmpxchg. These give guaranteed
> strong synchronisation and are required for non-SMP kernels running on
> an SMP hypervisor.
>
> Signed-off-by: Ian Pratt <ian.pratt@xxxxxxxxxxxxx>
> Signed-off-by: Christian Limpach <Christian.Limpach@xxxxxxxxxxxx>
> Signed-off-by: Chris Wright <chrisw@xxxxxxxxxxxx>
> Cc: Christoph Lameter <clameter@xxxxxxx>
> ---
> include/asm-i386/synch_bitops.h | 166 ++++++++++++++++++++++++++++++++++++++++
> include/asm-i386/system.h | 33 +++++++
> 2 files changed, 199 insertions(+)
>
> diff -r 935903fb1136 include/asm-i386/system.h
> --- a/include/asm-i386/system.h Mon May 08 19:20:42 2006 -0400
> +++ b/include/asm-i386/system.h Mon May 08 19:27:04 2006 -0400
> @@ -263,6 +263,9 @@ static inline unsigned long __xchg(unsig
> #define cmpxchg(ptr,o,n)\
> ((__typeof__(*(ptr)))__cmpxchg((ptr),(unsigned long)(o),\
> (unsigned long)(n),sizeof(*(ptr))))
> +#define synch_cmpxchg(ptr,o,n)\
> + ((__typeof__(*(ptr)))__synch_cmpxchg((ptr),(unsigned long)(o),\
> + (unsigned long)(n),sizeof(*(ptr))))
> #endif
>...

Do I miss anything, or is CONFIG_X86_XEN=y, CONFIG_M386=y an allowed
configuration that will result in a compile error?

cu
Adrian

--

"Is there not promise of rain?" Ling Tan asked suddenly out
of the darkness. There had been need of rain for many days.
"Only a promise," Lao Er said.
Pearl S. Buck - Dragon Seed

-
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/