On Thu, Apr 04, 2019 at 02:04:10PM -0400, Michael S. Tsirkin wrote: > On Thu, Apr 04, 2019 at 06:47:15PM +0200, Stefano Garzarella wrote: > > On Thu, Apr 04, 2019 at 11:52:46AM -0400, Michael S. Tsirkin wrote: > > > I simply love it that you have analysed the individual impact of > > > each patch! Great job! > > > > Thanks! I followed Stefan's suggestions! > > > > > > > > For comparison's sake, it could be IMHO benefitial to add a column > > > with virtio-net+vhost-net performance. > > > > > > This will both give us an idea about whether the vsock layer introduces > > > inefficiencies, and whether the virtio-net idea has merit. > > > > > > > Sure, I already did TCP tests on virtio-net + vhost, starting qemu in > > this way: > > $ qemu-system-x86_64 ... \ > > -netdev tap,id=net0,vhost=on,ifname=tap0,script=no,downscript=no \ > > -device virtio-net-pci,netdev=net0 > > > > I did also a test using TCP_NODELAY, just to be fair, because VSOCK > > doesn't implement something like this. > > Why not? > I think because originally VSOCK was designed to be simple and low-latency, but of course we can introduce something like that. Current implementation directly copy the buffer from the user-space in a virtio_vsock_pkt and enqueue it to be transmitted. Maybe we can introduce a buffer per socket where accumulate bytes and send it when it is full or when a timer is fired . We can also introduce a VSOCK_NODELAY (maybe using the same value of TCP_NODELAY for compatibility) to send the buffer immediately for low-latency use cases. What do you think? Thanks, Stefano
