[Spice-devel] xf86-video-qxl performance

[John A. Sullivan III]

On Thu, 2012-05-24 at 20:38 +0300, Yonit Halperin wrote:
> <snip>What OS your client has? When spice-server identifies WAN, it 
> automatically turn on Nagle's for the display channel (turns off 
> TCP_NODELAY), which should aggregate small tcp messages. However, it has 
> bad interaction with the delayed acks on the client side (especially in 
> Windows clients, where the default delayed ack timeout is 200ms iirc), 
> and overall it can lead to bigger latency between operations. We are 
> planning to get read of this, and aggregate the messages on the 
> application layer instead.
<snip>
That's very interesting.  When we did our initial testing which resulted
in our postponing deployment of SPICE on the WAN, the performance was
generally acceptable except for the noticeable latency between actions.
It smelled exactly like Nagle was active.  Your proposed change might
inspire us to give SPICE another try on the WAN - John