On Sat, Dec 13, 2008 at 11:40:11AM -0600, Eric Sandeen wrote: > Martin Steigerwald wrote: > > > At the moment it appears to me that disabling write cache may often give > > more performance than using barriers. And this doesn't match my > > expectation of write barriers as a feature that enhances performance. > > Why do you have that expectation? I've never seen barriers advertised > as enhancing performance. :) > > I do wonder why barriers on, write cache off is so slow; I'd have > thought the barriers were a no-op. Maybe I'm missing something. Barriers still enforce ordering in this case, so it affects the elevator algorithm.... Cheers, Dave. -- Dave Chinner david@xxxxxxxxxxxxx -- To unsubscribe from this list: send the line "unsubscribe linux-raid" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
