Re: [Qemu-devel] VSOCK benchmark and optimizations

[Stefano Garzarella]

On Wed, Apr 03, 2019 at 01:34:38PM +0100, Stefan Hajnoczi wrote:
> On Mon, Apr 01, 2019 at 06:32:40PM +0200, Stefano Garzarella wrote:
> > Hi Alex,
> > I'm sending you some benchmarks and information about VSOCK CCing qemu-devel
> > and linux-netdev (maybe this info could be useful for others :))
> > 
> > One of the VSOCK advantages is the simple configuration: you don't need to 
> > set
> > up IP addresses for guest/host, and it can be used with the standard POSIX
> > socket API. [1]
> > 
> > I'm currently working on it, so the "optimized" values are still work in
> > progress and I'll send the patches upstream (Linux) as soon as possible.
> > (I hope in 1 or 2 weeks)
> > 
> > Optimizations:
> > + reducing the number of credit update packets
> >   - RX side sent, on every packet received, an empty packet only to inform 
> > the
> >     TX side about the space in the RX buffer.
> > + increase RX buffers size to 64 KB (from 4 KB)
> > + merge packets to fill RX buffers
> > 
> > As benchmark tool I used iperf3 [2] modified with VSOCK support:
> > 
> >              host -> guest [Gbps]      guest -> host [Gbps]
> > pkt_size    before opt.  optimized    before opt.  optimized
> >   1K            0.5         1.6           1.4         1.4
> 
> This is a "large" small package size.  I think 64 bytes is a common
> "small" packet size and is worth benchmarking too.
> 

Okay, I'll add more small packet sizes for the benchmark.

> >   2K            1.1         3.1           2.3         2.5
> >   4K            2.0         5.6           4.2         4.4
> >   8K            3.2        10.2           7.2         7.5
> >   16K           6.4        14.2           9.4        11.3
> >   32K           9.8        18.9           9.2        17.8
> >   64K          13.8        22.9           8.8        25.0
> >   128K         17.6        24.5           7.7        25.7
> >   256K         19.0        24.8           8.1        25.6
> >   512K         20.8        25.1           8.1        25.4
> 
> Nice improvements!

Thanks :)

I'm cleaning the patches, doing step by step benchmarks and I hope I'll
send the series upstream in these days.

Stefano