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From:   Patrick Donnelly <pdonnell@redhat.com>
Date:   Thu, 21 Oct 2021 09:52:32 -0400
Message-ID: <CA+2bHPbqeH_rmmxcnQ9gq0K8gqtE4q69a8cFnherSJCxSwXV5Q@mail.gmail.com>
Subject: Re: [RFC PATCH] ceph: add remote object copy counter to fs client
To:     Jeff Layton <jlayton@kernel.org>
Cc:     =?UTF-8?Q?Lu=C3=ADs_Henriques?= <lhenriques@suse.de>,
        Ilya Dryomov <idryomov@gmail.com>,
        Ceph Development <ceph-devel@vger.kernel.org>,
        linux-kernel@vger.kernel.org
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On Wed, Oct 20, 2021 at 12:27 PM Jeff Layton <jlayton@kernel.org> wrote:
>
> On Wed, 2021-10-20 at 15:37 +0100, Lu=C3=ADs Henriques wrote:
> > This counter will keep track of the number of remote object copies done=
 on
> > copy_file_range syscalls.  This counter will be filesystem per-client, =
and
> > can be accessed from the client debugfs directory.
> >
> > Cc: Patrick Donnelly <pdonnell@redhat.com>
> > Signed-off-by: Lu=C3=ADs Henriques <lhenriques@suse.de>
> > ---
> > This is an RFC to reply to Patrick's request in [0].  Note that I'm not
> > 100% sure about the usefulness of this patch, or if this is the best wa=
y
> > to provide the functionality Patrick requested.  Anyway, this is just t=
o
> > get some feedback, hence the RFC.
> >
> > Cheers,
> > --
> > Lu=C3=ADs
> >
> > [0] https://github.com/ceph/ceph/pull/42720
> >
>
> I think this would be better integrated into the stats infrastructure.
>
> Maybe you could add a new set of "copy" stats to struct
> ceph_client_metric that tracks the total copy operations done, their
> size and latency (similar to read and write ops)?

I think it's a good idea to integrate this into "stats" but I think a
local debugfs file for some counters is still useful. The "stats"
module is immature at this time and I'd rather not build any qa tests
(yet) that rely on it.

Can we generalize this patch-set to a file named "op_counters" or
similar and additionally add other OSD ops performed by the kclient?

--=20
Patrick Donnelly, Ph.D.
He / Him / His
Principal Software Engineer
Red Hat, Inc.
GPG: 19F28A586F808C2402351B93C3301A3E258DD79D