On Sat, May 29, 2010 at 11:34 AM, Christoph Hellwig <hch@xxxxxxxxxxxxx> wrote: > In what benchmark do you see worse results for aio=native compared to > aio=threads? Sequential reads using 4 concurrent dd if=/dev/vdb iflag=direct of=/dev/null bs=8k processes. 2 vcpu guest with 4 GB RAM, virtio block devices, cache=none. Host storage is a striped LVM volume. Host kernel kvm.git and qemu-kvm.git userspace. aio=native and aio=threads each run 3 times. Result: aio=native has 15% lower throughput than aio=threads. I haven't looked into this so I don't know what is causes these results. Stefan -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
