Re: Interested in Contributing to Kvm-kernel [ Networking project: reduce networking latency ]

["Michael S. Tsirkin" <mst@redhat.com>]

On Sat, Nov 19, 2016 at 01:15:53PM +0530, Abhinav Gupta wrote:
> Hello,
>    I'm interested in taking ownership for the project reduce networking latency
> as mentioned on 
> 
> http://www.linux-kvm.org/page/NetworkingTodo#projects_in_need_of_an_owner
> 
> 
>   • reduce networking latency:
> 
>  allow handling short packets from softirq or VCPU context
>  Plan:
>    We are going through the scheduler 3 times
>    (could be up to 5 if softirqd is involved)
>    Consider RX: host irq -> io thread -> VCPU thread ->
>    guest irq -> guest thread.
>    This adds a lot of latency.
>    We can cut it by some 1.5x if we do a bit of work
>    either in the VCPU or softirq context.
>  Testing: netperf TCP RR - should be improved drastically
>           netperf TCP STREAM guest to host - no regression
>  Contact: MST
> 
> 
> I have a sound understanding of networking and c.
> 
> Please can anyone recommend where I can start from in the source tree.
> 
> Thanks,
> Abhinav Gupta

I'd start looking at vhost and tun drivers, ioeventfd and irqfd in kvm.

-- 
MST