> > The iozone results seem a bit consistent and all values seem to be noisy and > not say much. I don't know why really, maybe the test is simply not relevant, > the tests don't seem to be significantly affected by any of the patches, so > let's focus on the dd and find tests. Maybe use a more selective testing mode instead of -az. Also maybe you want to clear the cache between the sequential and random tests: #sync #echo 3 > /proc/sys/vm/drop_caches #sync It helps to obtain a more robust results. > What immediately jumps out at you is that linear read/writes perform just as > nicely or actually better with MQ than with the old block layer. How come 22.7MB/s before vs. 22.1MB/s after is better? or did I misunderstand the output? Also as dd is probably using the buffer cache, unlike the iozone test in which you properly used -I for direct mode to isolate the blk-mq effect - does it really say much?
