From: Jason Wang

quoted

On Mon, Dec 01, 2014 at 06:17:03PM +0800, Jason Wang wrote:

quoted

 Hello:

 We used to orphan packets before transmission for virtio-net. This
breaks
 socket accounting and can lead serveral functions won't work, e.g:

 - Byte Queue Limit depends on tx completion nofication to work.
 - Packet Generator depends on tx completion nofication for the last
   transmitted packet to complete.
 - TCP Small Queue depends on proper accounting of sk_wmem_alloc to
work.

 This series tries to solve the issue by enabling tx interrupts. To
minize
 the performance impacts of this, several optimizations were used:

 - In guest side, virtqueue_enable_cb_delayed() was used to delay the tx
   interrupt untile 3/4 pending packets were sent.

Doesn't that give problems for intermittent transmits?

...

	David