svn commit: r259765 - in head/sys: fs/nfsserver nfs nfsserver

[Alexander Motin]

On 23.12.2013 13:14, Konstantin Belousov wrote:
> On Mon, Dec 23, 2013 at 08:43:17AM +0000, Alexander Motin wrote:
>> Author: mav
>> Date: Mon Dec 23 08:43:16 2013
>> New Revision: 259765
>> URL: http://svnweb.freebsd.org/changeset/base/259765
>>
>> Log:
>>    Fix RPC server threads file handle affinity to work better with ZFS.
>>
>>      Instead of taking 8 specific bytes of file handle to identify file during
>>    RPC thread affitinity handling, use trivial hash of the full file handle.
>>    ZFS's struct zfid_short does not have padding field after the length field,
>>    as result, originally picked 8 bytes are loosing lower 16 bits of object ID,
>>    causing many false matches and unneeded requests affinity to same thread.
>>      This fix substantially improves NFS server latency and scalability in SPEC
>>    NFS benchmark by more flexible use of multiple NFS threads.
>>
>>    Sponsored by:	iXsystems, Inc.
>
> Did you audited all other filesystems to ensure that struct fid.
> fid_data0 is filled (zeroed) consistently ?

Yes, I did a tree search and in all found cases the structure was 
pre-erased.

> Also, this constitues subtle VFS KBI change.

In what way it touched VFS KBI? I indeed modified RPC FHA KPI to make it 
more safe, but I don't see how it may touch anything else then two of 
our NFS servers.

-- 
Alexander Motin