Re: [Qemu-devel] [RFC v9 18/27] virtio-blk: Call ioctl() directly instead of irqfd

2012-07-19 Thread Stefan Hajnoczi
On Wed, Jul 18, 2012 at 4:40 PM, Michael S. Tsirkin m...@redhat.com wrote: On Wed, Jul 18, 2012 at 04:07:45PM +0100, Stefan Hajnoczi wrote: Optimize for the MSI-X enabled and vector unmasked case where it is possible to issue the KVM ioctl() directly instead of using irqfd. Why? Is an ioctl

Re: [Qemu-devel] [RFC v9 18/27] virtio-blk: Call ioctl() directly instead of irqfd

2012-07-19 Thread Michael S. Tsirkin
On Thu, Jul 19, 2012 at 10:11:49AM +0100, Stefan Hajnoczi wrote: On Wed, Jul 18, 2012 at 4:40 PM, Michael S. Tsirkin m...@redhat.com wrote: On Wed, Jul 18, 2012 at 04:07:45PM +0100, Stefan Hajnoczi wrote: Optimize for the MSI-X enabled and vector unmasked case where it is possible to issue

[RFC v9 18/27] virtio-blk: Call ioctl() directly instead of irqfd

2012-07-18 Thread Stefan Hajnoczi
Optimize for the MSI-X enabled and vector unmasked case where it is possible to issue the KVM ioctl() directly instead of using irqfd. This patch introduces a new virtio binding function which tries to notify in a thread-safe way. If this is not possible, the function returns false. Virtio

Re: [RFC v9 18/27] virtio-blk: Call ioctl() directly instead of irqfd

2012-07-18 Thread Michael S. Tsirkin
On Wed, Jul 18, 2012 at 04:07:45PM +0100, Stefan Hajnoczi wrote: Optimize for the MSI-X enabled and vector unmasked case where it is possible to issue the KVM ioctl() directly instead of using irqfd. Why? Is an ioctl faster? This patch introduces a new virtio binding function which tries to