On Tue, Dec 18, 2012 at 02:20:20PM +0200, Michael S. Tsirkin wrote: > At the moment when vector is masked virtio will poll it > in userspace, even if it is handled by irqfd. > This is done in order to update pending bits, but > it's not really required until someone reads the pending bits. > On the other hand this read results in extra io thread wakeups. > > As we only implement the pending bits as a compatibility > feature (read - real drivers don't use it), we can defer > the irqfd poll until the read actually happens. > > This does not seem to affect vhost-net speed > in simple benchmarks but could help block: both > vhost-blk and dataplane when using irqfd, > and I also think this is cleaner than enabling/disabling > notifiers all the time. > > This will also be the basis for future optimizations. Note: this is on top of the typesafe bindings patch v3 I sent previously. You can get the whole bundle from: git://git.kernel.org/pub/scm/virt/kvm/mst/qemu.git pci -- MST -- 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
