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From: Cedric Blancher <cedric.blancher@gmail.com>
Date: Thu, 23 Nov 2023 00:10:21 +0100
Message-ID: <CALXu0Ucy4qK1T9-WMssYaxSvhSBSyyxiwP2sjLgMD_wXQs43Qw@mail.gmail.com>
Subject: Re: TCP_KEEPALIVE for Linux NFS client?
To: Linux NFS Mailing List <linux-nfs@vger.kernel.org>
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On Thu, 23 Nov 2023 at 00:03, Calum Mackay <calum.mackay@oracle.com> wrote:
>
> hi Ced,
>
> On 22/11/2023 10:48 pm, Cedric Blancher wrote:
> > On Mon, 20 Nov 2023 at 03:57, Olga Kornievskaia <aglo@umich.edu> wrote:
> >>
> >> Hi Ced,
> >>
> >> Why do you think it doesn't use it? Have you looked at a network trace
> >> of an idle connection? I seem to recall seeing keep-alive being used.
> >
> > Well, I don't see a setsockopt(TCP_KEEPALIVE) in the libtirpc code?
>
> We have this, in the kernel RPC code:
>
>         https://elixir.bootlin.com/linux/latest/source/net/sunrpc/xprtsoc=
k.c#L2257
>
> which might be it.

Yay, But how does the kernel get the fd from libtirpc?

Also, how can I turn this:

/* TCP Keepalive options */
sock_set_keepalive(sock->sk);
tcp_sock_set_keepidle(sock->sk, keepidle);
tcp_sock_set_keepintvl(sock->sk, keepidle);
tcp_sock_set_keepcnt(sock->sk, keepcnt);

/* TCP user timeout (see RFC5482) */
tcp_sock_set_user_timeout(sock->sk, timeo);

into setsockopt() from userland code? Does the BSD socket library have
such options?

Ced

>
> cheers,
> calum.
>
> >
> > Ced
> >
> >>
> >> On Fri, Nov 17, 2023 at 8:02=E2=80=AFPM Cedric Blancher
> >> <cedric.blancher@gmail.com> wrote:
> >>>
> >>> Good morning!
> >>>
> >>> Why does the Linux NFS client not use TCP_KEEPALIVE for its TCP
> >>> connections? What are the pro and cons of using that for NFS TCP
> >>> connections?
> >>>
> >>> Ced
> >>> --
> >>> Cedric Blancher <cedric.blancher@gmail.com>
> >>> [https://plus.google.com/u/0/+CedricBlancher/]
> >>> Institute Pasteur
> >
> >
> >
>
> --
> Calum Mackay
> Linux Kernel Engineering
> Oracle Linux and Virtualisation
>


--=20
Cedric Blancher <cedric.blancher@gmail.com>
[https://plus.google.com/u/0/+CedricBlancher/]
Institute Pasteur