Re: [PATCH v3 0/2] viritofsd: Add support for FUSE_HANDLE_KILLPRIV_V2

[Dr. David Alan Gilbert]

* Vivek Goyal (vgoyal@redhat.com) wrote:
> Hi,
> 
> This is V3 of the patches. V2 had been posted here.
> 
> https://listman.redhat.com/archives/virtio-fs/2020-November/msg00084.html
> 
> These patches add support for FUSE_HANDLE_KILLPRIV_V2. This is basically
> a feature file server can opt-in. And with xattr enabled, this improves
> write performance many fold. Ran following fio command while virtiofsd is
> running with options "-o cache=auto" and "-o xattr".

Queued

> fio libaio random writes
> ------------------------
> fio --ioengine=libaio --direct=1 --gtod_reduce=1 --name=test 
> --filename=/mnt/virtiofs/random_read_write.fio --bs=4k --iodepth=64 --size=4G 
> --readwrite=randwrite
> 
> Without patches:
>  WRITE: bw=84.6MiB/s (88.7MB/s), 84.6MiB/s-84.6MiB/s (88.7MB/s-88.7MB/s), 
> io=4096MiB (4295MB), run=48436-48436msec
> 
> With patches:
>   WRITE: bw=273MiB/s (286MB/s), 273MiB/s-273MiB/s (286MB/s-286MB/s), 
> io=4096MiB (4295MB), run=15003-15003msec
> 
> So with these patches, for this particular workload, there is roughly
> more than 200% improvement.
> 
> fio psync random writes
> -----------------------
> Even, single queue depth writes with ioengine=psync, how significant
> improvement. Performance jumps from roughly 35MiB/s to 70MiB/s.
> 
> fio --ioengine=psync --name=test 
> --filename=/mnt/virtiofs/random_read_write.fio --bs=4k --size=4G 
> --readwrite=randwrite
> 
> Without patches:
>   WRITE: bw=35.0MiB/s (36.7MB/s), 35.0MiB/s-35.0MiB/s (36.7MB/s-36.7MB/s), 
> io=4096MiB (4295MB), run=116932-116932msec
> 
> With patches:
>  WRITE: bw=69.9MiB/s (73.3MB/s), 69.9MiB/s-69.9MiB/s (73.3MB/s-73.3MB/s), 
> io=4096MiB (4295MB), run=58596-58596msec
> 
> In V3 I rebased these patches to latest upstream. There were few
> conflicts due to recent security fixes from Stefan. Resolved these
> conflicts.
> 
> Thanks
> Vivek
> 
> Vivek Goyal (2):
>   virtiofsd: Save error code early at the failure callsite
>   viriofsd: Add support for FUSE_HANDLE_KILLPRIV_V2
> 
>  tools/virtiofsd/fuse_common.h    | 15 ++++++
>  tools/virtiofsd/fuse_lowlevel.c  | 11 +++-
>  tools/virtiofsd/fuse_lowlevel.h  |  1 +
>  tools/virtiofsd/passthrough_ll.c | 93 ++++++++++++++++++++++++++++----
>  4 files changed, 108 insertions(+), 12 deletions(-)
> 
> -- 
> 2.25.4
> 
> 
-- 
Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK