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From:   Chuck Lever III <chuck.lever@oracle.com>
To:     Jeff Layton <jlayton@kernel.org>
CC:     Linux NFS Mailing List <linux-nfs@vger.kernel.org>,
        Bruce Fields <bfields@fieldses.org>
Subject: Re: [PATCH RFC 0/2] Replace file_hashtbl with an rhashtable
Thread-Topic: [PATCH RFC 0/2] Replace file_hashtbl with an rhashtable
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Date:   Thu, 29 Sep 2022 16:20:59 +0000
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> On Sep 28, 2022, at 6:23 AM, Jeff Layton <jlayton@kernel.org> wrote:
>=20
> On Tue, 2022-09-27 at 13:22 -0400, Chuck Lever wrote:
>> Hi, while testing I noticed that sometimes thousands of items are
>> inserted into file_hashtbl, but it's a small fixed-size hash. That
>> makes the buckets in file_hashtbl larger than two or three items.
>> The comparison function (fh_match) used while walking through the
>> buckets is expensive and cache-unfriendly.
>>=20
>> The following patches seem to help alleviate that overhead.
>>=20
>> ---
>>=20
>> Chuck Lever (2):
>>      NFSD: Use const pointers as parameters to fh_ helpers.
>>      NFSD: Use rhashtable for managing nfs4_file objects
>>=20
>>=20
>> fs/nfsd/nfs4state.c | 227 ++++++++++++++++++++++++++++++--------------
>> fs/nfsd/nfsfh.h     |  10 +-
>> fs/nfsd/state.h     |   5 +-
>> 3 files changed, 162 insertions(+), 80 deletions(-)
>>=20
>> --
>> Chuck Lever
>>=20
>=20
> This set all looks reasonable to me, and I like the idea of moving to
> rhashtable. You can add:
>=20
> Reviewed-by: Jeff Layton <jlayton@kernel.org>

Thanks for having a look. I'm not sure I want to push these as soon
as v6.1, as they are quite fresh. That might increase the likelihood
of collisions when you work on cleaning up stateID reference counting.


--
Chuck Lever