Re: virtiofs vs 9p performance

[Vivek Goyal]

On Fri, Sep 25, 2020 at 10:06:41AM +0200, Christian Schoenebeck wrote:
> On Freitag, 25. September 2020 00:10:23 CEST Vivek Goyal wrote:
> > In my testing, with cache=none, virtiofs performed better than 9p in
> > all the fio jobs I was running. For the case of cache=auto  for virtiofs
> > (with xattr enabled), 9p performed better in certain write workloads. I
> > have identified root cause of that problem and working on
> > HANDLE_KILLPRIV_V2 patches to improve WRITE performance of virtiofs
> > with cache=auto and xattr enabled.
> 
> Please note, when it comes to performance aspects, you should set a 
> reasonable 
> high value for 'msize' on 9p client side:
> https://wiki.qemu.org/Documentation/9psetup#msize

Interesting. I will try that. What does "msize" do? 

> 
> I'm also working on performance optimizations for 9p BTW. There is plenty of 
> headroom to put it mildly. For QEMU 5.2 I started by addressing readdir 
> requests:
> https://wiki.qemu.org/ChangeLog/5.2#9pfs

Nice. I guess this performance comparison between 9p and virtiofs is good.
Both the projects can try to identify weak points and improve performance.

Thanks
Vivek