Re: [vde-users] New queuing discipline on experimental code

[Renzo D. <re...@cs...>]

On Mon, Mar 28, 2011 at 05:27:01PM +0200, Simone Abbakus wrote:
> Now works and it's much much better than the timedout version! (and
> better than my dynamic timedout version).
> 
> I get 510 Mb/s throughput UDP with _no_ OOO packets (latest release
> version was 370 Mb/s and a lot of OOO packets).
> TCP throughput is 536 Mb/s (was 478 Mb/s on latest release version).
> 
> These results are obviously in the case of 2 vm's and one switch but
> I'm confident about a general improvements.
It is possible to tune the performance by setting the packet buffer size (# of packets).

The default value is 128 packets but it is possible to change the default
value for new ports by the mgmt command:

port/defqlen

e.g. port/defqlen 256

It is also possible to set the max size of the packet buffer port by port
(or more precisely entrypoint by entrypoint). It is the purpose of the following command:

port/epqlen

e.g:

--------------------
vde: port/print

Port 0001 untagged_vlan=0000 ACTIVE - Unnamed Allocatable
 Current User: NONE Access Control: (User: NONE - Group: NONE)
 IN:  pkts     537475          bytes            581996735
 OUT: pkts     401026          bytes            481438953
  -- endpoint ID 0007 module tuntap      : tap0
              unsent packets: 0 max 128
Success

vde: port/epqlen 1 7 1024

Success
----------------

The port/print output shows that it is possible to inspect the current length of the
unsent packet queue at run time.

	renzo