On 05/16/2011 01:26 PM, Christoph Lameter wrote: > A simple implementation that only supports the word size and does not > have a fallback mode (would require a spinlock). > > And 32 and 64 bit support for cmpxchg_double. cmpxchg double uses > the cmpxchg8b or cmpxchg16b instruction on x86 processors to compare > and swap 2 machine words. This allows lockless algorithms to move more > context information through critical sections. > > Set a flag CONFIG_CMPXCHG_DOUBLE to signal the support of that feature > during kernel builds. > > Signed-off-by: Christoph Lameter <cl@xxxxxxxxx> > > > +config CMPXCHG_DOUBLE > + def_bool X86_64 || (X86_32 && !M386) > + CMPXCHG16B is not a baseline feature for the Linux x86-64 build, and CMPXCHG8G is a Pentium, not a 486, feature. Nacked-by: H. Peter Anvin <hpa@xxxxxxxxx> -hpa -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxxx For more info on Linux MM, see: http://www.linux-mm.org/ . Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/ Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>