Re: [Qemu-devel] Make virtio-net.c ring size configurable?

[xchenum]

Luke, I might have a similar problem... I am wondering if you end up 
increasing the ring buffer size yourself.

My problem is on the tx side. When sending many small udp packets, I am 
seeing "outgoing packets dropped" in "netstat -s" increase quickly. 
Increasing txqueue of the interface and wmem size in sysctl doesn't seem to 
help at all. tx ring size is what I am looking at now. My VM however is 
connected to a bridge and then to OpenVSwitch - so I might have other 
bottlenecks...

Thanks!

On Friday, February 14, 2014 at 8:43:14 AM UTC-5, Luke Gorrie wrote:
>
> Howdy!
>
> Observation: virtio-net.c hard-codes the vring size to 256 buffers.
>
> Could this reasonably be made configurable, or would that be likely to 
> cause a problem?
>
> In Snabb Switch we are creating a 1:1 mapping between Virtio-net 
> descriptors and VMDq hardware receive descriptors. The VMDq queues support 
> 32768 buffers and I'd like to match this on the QEMU/Virtio-net side -- or 
> at least come close.
>
> Cheers!
> -Luke
>
>
>