I hit a weirdness yesterday, just want to mention it in case you notice it too.
When running vanilla qemu-kvm I forgot to use aio=native. When I compared the results against virtio-blk-data-plane (which *always* uses Linux AIO) I was surprised to find average 4k read latency was lower and the standard deviation was also lower. So from now on I will run tests both with and without aio=native. aio=native should be faster and if I can reproduce the reverse I'll try to figure out why. Stefan -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
