Hi Rusty, On 13.02.2012 10:25, Rusty Russell wrote: > On Fri, 10 Feb 2012 15:36:39 +0100, Dongsu Park <dongsu.park@xxxxxxxxxxxxxxxx> wrote: > > Hi, > > > > Recently I observed performance regression regarding virtio-blk, > > especially different IO bandwidths between qemu-kvm 0.14.1 and 1.0. > > So I want to share the benchmark results, and ask you what the reason > > would be. > > Interesting. There are two obvious possibilities here. One is that > qemu has regressed, the other is that virtio_blk has regressed; the new > qemu may negotiate new features. Please do the following in the guest > with old and new qemus: > > cat /sys/class/block/vdb/device/features > > (eg, here that gives: 0010101101100000000000000000100e0). I did that on guest VM, using both qemu-kvm 0.14.1 and 1.0. (cat /sys/class/block/vdb/device/features) using qemu-kvm 0.14.1: 0010101101100000000000000000100000000000000000000000000000000000 using qemu-kvm 1.0: 0010101101100000000000000000110000000000000000000000000000000000 >From my understanding, both of them have the same virtio features. Please correct me if I'm wrong. Regards, Dongsu -- 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
