On Tue, Aug 27, 2002 at 12:42:18PM +1000, Simon Burge wrote:

 > So RAS is faster in all cases.  I'm thinking of something like:
 > 
 > 	if sysctl(hw.ncpus == 1) {
 > 		RAS lock
 > 	} else {
 > 		if (sysctl(machdep.llsc) {
 > 			test-and-set lock
 > 		} else {
 > 			/* Eek!  SMP without ll/sc */
 > 			syscall lock
 > 		}
 > 	}

It would probably be reasonable to make the use of RAS the default
on *all* platforms, if there is only one CPU.

-- 
        -- Jason R. Thorpe <thorpej@wasabisystems.com>