On Sun, Apr 26 2009, Joshua Aune wrote: > > On Apr 26, 2009, at 7:44 AM, Chris Worley wrote: > >> The results show two latency numbers: clat and slat... what are these? > > slat is not there for the sync engines but exists for libaio, submit > latency. clat sounds like completion latency. It's in the HOWTO :-) Basically slat is the time it too to enter the kernel and submit the IO (submission latency) and clat is the time it took from submission to the IO completed (completion latency). With the sync engines you cannot separate the two, since when the submission syscall completes the IO has also completed. Hence they have only clat numbers, where the async engine has the ability to measure both. -- Jens Axboe -- To unsubscribe from this list: send the line "unsubscribe fio" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
