Hi Bruce-
> On Aug 11, 2020, at 9:31 AM, Chuck Lever <chuck.lever@xxxxxxxxxx> wrote:
>
>> On Aug 10, 2020, at 4:10 PM, Bruce Fields <bfields@xxxxxxxxxxxx> wrote:
>>
>> On Mon, Aug 10, 2020 at 04:01:00PM -0400, Chuck Lever wrote:
>>> Roughly the same result with this patch as with the first one. The
>>> first one is a little better. Plus, I think the Solaris NFS server
>>> hands out write delegations on v4.0, and I haven't heard of a
>>> significant issue there. It's heuristics may be different, though.
>>>
>>> So, it might be that NFSv4.0 has always run significantly slower. I
>>> will have to try a v5.4 or older server to see.
>>
>> Oh, OK, I was assuming this was a regression.
>
> Me too. Looks like it is: NFSv4.0 always runs slower, but I see
> it get significantly worse between v5.4 and 5.5. I will post more
> quantified results soon.
It took me a while to get plausible bisection results. The problem
appears in the midst of the NFSD filecache patches merged in v5.4.
In order of application:
5920afa3c85f ("nfsd: hook nfsd_commit up to the nfsd_file cache")
961.68user 5252.40system 20:12.30elapsed 512%CPU, 2541 DELAY errors
These results are similar to v5.3.
fd4f83fd7dfb ("nfsd: convert nfs4_file->fi_fds array to use nfsd_files")
Does not build
eb82dd393744 ("nfsd: convert fi_deleg_file and ls_file fields to nfsd_file")
966.92user 5425.47system 33:52.79elapsed 314%CPU, 1330 DELAY errors
Can you take a look and see if there's anything obvious?
--
Chuck Lever
