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From:   Chuck Lever III <chuck.lever@oracle.com>
To:     Bruce Fields <bfields@fieldses.org>
CC:     Dai Ngo <dai.ngo@oracle.com>,
        Linux NFS Mailing List <linux-nfs@vger.kernel.org>
Subject: Re: [PATCH RFC 1/1] nfsd: Initial implementation of NFSv4 Courteous
 Server
Thread-Topic: [PATCH RFC 1/1] nfsd: Initial implementation of NFSv4 Courteous
 Server
Thread-Index: AQHXWKRU4nAovJ01SEuUWcwucjnsZasW4MaAgAAIUoA=
Date:   Wed, 16 Jun 2021 16:32:26 +0000
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 <20210616160239.GC4943@fieldses.org>
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> On Jun 16, 2021, at 12:02 PM, J. Bruce Fields <bfields@fieldses.org> wrot=
e:
>=20
> On Thu, Jun 03, 2021 at 02:14:38PM -0400, Dai Ngo wrote:
>> . instead of destroy the client anf all its state on conflict, only dest=
roy
>> the state that is conflicted with the current request.
>=20
> The other todos I think have to be done before we merge, but this one I
> think can wait.

I agree on both points: this one can wait, but the others
should be done before merge.


>> . destroy the COURTESY_CLIENT either after a fixed period of time to rel=
ease
>> resources or as reacting to memory pressure.
>=20
> I think we need something here, but it can be pretty simple.

We should work out a policy now.

A lower bound is good to have. Keep courtesy clients at least
this long. Average network partition length times two as a shot
in the dark. Or it could be N times the lease expiry time.

An upper bound is harder to guess at. Obviously these things
will go away when the server reboots. The laundromat could
handle this sooner. However using a shrinker might be nicer and
more Linux-y, keeping the clients as long as practical, without
the need for adding another administrative setting.


--
Chuck Lever