Open Stack

This is great - thank you Vivek.

On 1/15/19, 11:38 AM, "Vivek Goyal" <vgoyal at redhat.com> wrote:

    On Thu, Dec 27, 2018 at 10:57:21AM +0800, jiangyiwen wrote:
    
    [..]
    > >>
    > >> 4. When I use fio with psync, write/read only 20% improve than 9p, I think
    > >> psync can be more used than mmap. This user-case may need to improved.
    > > 
    > > Can you send me your fio job. I want to try it out.
    > > 
    > 
    > fio -filename=/mnt/virtio_fs/file -rw=read -bs=4k -size=6G -iodepth=1 -ioengine=psync -numjobs=1 -group_reporting -name=xxx -time_based -runtime=120
    
    Ok, finally I tried this in bunch of configurations. without dax and
    cache=none, I see roughly 100% improvement.
    
    cache=none
    ==========
    virtio-9p: 28MB/s
    virtio-fs: 59MB/s
    
    Above is without dax enabled and libfuse daemon filters O_DIRECT flag on
    host so that file will be cached in host (despite the fact guest opened
    it with O_DIRECT). 
    
    I then tried "cache=always" and did direct I/O from guest. This will avoid
    page cache in guest but will use page cache on host.
    
    cache=always
    ===========
    virtio-fs: 52MB/s
    virtio-fs (dax): 175MB/s
    
    Notice that with dax performance is alsmost 5x times better as compared to
    virtio-9p.
    
    Following is my fio job for testing.
    
    =======================================
    [global]
    name=fio-psync
    rw=read
    direct=1
    numjobs=1
    runtime=60
    bs=4k
    
    [file1]
    size=6G
    ioengine=psync
    iodepth=1
    filename=fio-psync-file
    ========================================
    
    So I think even without dax, performance improvement is significant and
    enabling dax speeds it up very significantly.
    
    Thanks
    Vivek
    
    _______________________________________________
    kata-dev mailing list
    kata-dev at lists.katacontainers.io
    http://lists.katacontainers.io/cgi-bin/mailman/listinfo/kata-dev