[Virtio-fs] [PATCH] virtiofsd: Use --thread-pool-size=0 to mean no thread pool

[Vivek Goyal]

On Tue, Nov 17, 2020 at 04:00:09PM +0000, Venegas Munoz, Jose Carlos wrote:
> >   Not sure what the default is for 9p, but comparing
> >   default to default will definitely not be apples to apples since this
> >   mode is nonexistent in 9p.
> 
> In Kata we are looking for the best config for fs compatibility and performance. So even if are no apples to apples,
> we are for the best config for both and comparing the best that each of them can do.
> 
> In the case of Kata for 9pfs(this is the config we have found has better performance and fs compatibility  in general) we have:
> ```
> -device virtio-9p-pci # device type
> ,disable-modern=false 
> ,fsdev=extra-9p-kataShared # attr: device id  for fsdev
> ,mount_tag=kataShared  # attr: tag on how will be found de sharedfs 
> ,romfile= 
> -fsdev local  #local: Simply lets QEMU call the individual VFS functions (more or less) directly on host.
> ,id=extra-9p-kataShared 
> ,path=${SHARED_PATH} # attrs: path to share
> ,security_model=none #    
> #    passthrough: Files are stored using the same credentials as they are created on the guest. This requires QEMU to run as # root.
> #    none: Same as "passthrough" except the sever won't report failures if it fails to set file attributes like ownership # 
> #  (chown). This makes a passthrough like security model usable for people who run kvm as non root.
> ,multidevs=remap
> ```
> 
> The mount options are:
> ```
> trans=virtio 
>     ,version=9p2000.L 
>     ,cache=mmap 
>     ,"nodev" # Security: The nodev mount option specifies that the filesystem cannot contain special devices. 
>     ,"msize=8192" # msize: Maximum packet size including any headers.
> ```

How much RAM you are giving to these containers when using virtio-9p?

Vivek