On 06/01/2011 07:13 AM, Christoph Lameter wrote: >> >> Per your own description: >> >> "CMPXCHG_DOUBLE only compiles in detection support. It needs to be set >> if there is a chance that processor supports these instructions." >> >> That condition is always TRUE, so no Kconfig is needed. > > There are several early processors (especially from AMD it seems) that do > not support cmpxchg16b. If one builds a kernel specifically for the early > cpus then the support does not need to be enabled. > We don't support building kernels specifically for those early CPUs as far as I know. Besides, it is a very small set. Even if we did, the conditional as you have specified it is wrong, and I mean "not even in the general ballpark of correct". > This is also an issue going beyond x86. Other platforms mostly do not > support double word cmpxchg so the code for this feature also does not > need to be included for those builds. That's fine; just set it unconditionally for x86. -hpa -- H. Peter Anvin, Intel Open Source Technology Center I work for Intel. I don't speak on their behalf. -- 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>