On Tue, Feb 01, 2011 at 01:53:05PM -0800, Shirley Ma wrote:

On Tue, 2011-02-01 at 23:42 +0200, Michael S. Tsirkin wrote:

quoted

On Tue, Feb 01, 2011 at 01:32:35PM -0800, Shirley Ma wrote:

quoted

On Tue, 2011-02-01 at 23:24 +0200, Michael S. Tsirkin wrote:

quoted

My theory is that the issue is not signalling.
Rather, our queue fills up, then host handles
one packet and sends an interrupt, and we
immediately wake the queue. So the vq
once it gets full, stays full.

quoted

From the printk debugging output, it might not be exactly the case.

The

quoted

ring gets full, run a bit, then gets full, then run a bit, then

full...

Yes, but does it get even half empty in between?

Sometimes, most of them not half of empty in between. But printk slow
down the traffics, so it's not accurate. I think your patch will improve
the performance if it signals guest when half of the ring size is
empty. 

But you manage signal by using TX bytes,

There are flags for bytes, buffers and packets.
Try playing with any one of them :)
Just be sure to use v2.

I would like to change it to
half of the ring size instead for signaling. Is that OK?

Shirley

Sure that is why I made it a parameter so you can experiment.

-- 
MST