From: Rodrigo Moya <rodrigo.moya@collabora.co.uk>
To: David Miller <davem@davemloft.net>
Cc: javier.martinez@collabora.co.uk, javier@collabora.co.uk,
eric.dumazet@gmail.com, lennart@poettering.net,
kay.sievers@vrfy.org, alban.crequy@collabora.co.uk,
bart.cerneels@collabora.co.uk, sjoerd.simons@collabora.co.uk,
netdev@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH 0/10] af_unix: add multicast and filtering features to AF_UNIX
Date: Tue, 28 Feb 2012 11:47:39 +0100 [thread overview]
Message-ID: <1330426059.2139.21.camel@megeve> (raw)
In-Reply-To: <20120227.140535.1623396420455657443.davem@davemloft.net>
Hi David
On Mon, 2012-02-27 at 14:05 -0500, David Miller wrote:
> From: Javier Martinez Canillas <javier.martinez@collabora.co.uk>
> Date: Mon, 27 Feb 2012 15:00:06 +0100
>
> > Primary for performance reasons. D-bus is an IPC system for processes in
> > the same machine so traversing the whole TCP/IP stack seems a little
> > overkill to me.
>
> You haven't actually tested what the cost of this actually is, so what
> you're saying is mere speculation. In many cases TCP/UDP over
> loopback is actually faster than AF_UNIX.
>
you're right we haven't tested this, but because of the other points in
Javier's mail, which are the special semantics we need for this to fit
the D-Bus usage:
> - total order is guaranteed: If sender A sends a message before B,
then
> receiver C and D should both get message A first and then B.
>
> - slow readers: dropping packets vs blocking the sender. Although
> datagrams are not reliable on IP, datagrams on Unix sockets are
never
> lost. So if one receiver has its buffer full the sender is blocked
> instead of dropping packets. That way we guarantee a reliable
> communication channel.
>
> - multicast group acess control: controlling who can join the
multicast
> group.
>
> - multicast on loopback is not supported: which means we have to use a
> NIC (i.e: eth0).
Because of all of this, UDP/IP multicast wasn't even considered as an
option. We might be wrong in some/all of those, so could you please
comment on them to check if that's so?
thanks
next prev parent reply other threads:[~2012-02-28 10:47 UTC|newest]
Thread overview: 55+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-02-20 15:57 [PATCH 0/10] af_unix: add multicast and filtering features to AF_UNIX Javier Martinez Canillas
2012-02-20 15:57 ` [PATCH 01/10] af_unix: Documentation on multicast unix sockets Javier Martinez Canillas
2012-02-20 15:57 ` [PATCH 02/10] af_unix: Add constant for unix socket options level Javier Martinez Canillas
2012-02-20 15:57 ` [PATCH 03/10] af_unix: add setsockopt on unix sockets Javier Martinez Canillas
2012-02-20 16:20 ` David Miller
2012-02-20 19:13 ` [PATCH 0/10] af_unix: add multicast and filtering features to AF_UNIX Colin Walters
2012-02-21 8:07 ` Rodrigo Moya
2012-02-24 20:36 ` David Miller
2012-02-27 14:00 ` Javier Martinez Canillas
2012-02-27 19:05 ` David Miller
2012-02-28 10:47 ` Rodrigo Moya [this message]
2012-02-28 14:28 ` David Lamparter
2012-02-28 15:24 ` Javier Martinez Canillas
2012-02-28 16:33 ` Javier Martinez Canillas
2012-02-28 19:05 ` David Miller
2012-03-01 11:57 ` Javier Martinez Canillas
2012-03-01 12:26 ` Eric Dumazet
2012-03-01 12:33 ` David Laight
2012-03-01 12:50 ` Rodrigo Moya
2012-03-01 12:59 ` Eric Dumazet
2012-03-01 13:56 ` Javier Martinez Canillas
2012-03-01 16:00 ` Eric Dumazet
2012-03-01 16:02 ` Luiz Augusto von Dentz
2012-03-01 17:06 ` Javier Martinez Canillas
2012-03-01 17:59 ` Eric Dumazet
2012-03-01 18:10 ` Alan Cox
2012-03-01 19:02 ` Javier Martinez Canillas
2012-03-01 19:29 ` Javier Martinez Canillas
2012-03-01 18:53 ` David Dillow
2012-03-01 20:55 ` David Miller
2012-03-02 4:40 ` Stephen Hemminger
2012-03-01 20:44 ` David Miller
2012-03-01 22:01 ` Luiz Augusto von Dentz
2012-03-01 22:08 ` David Miller
2012-03-02 8:39 ` Luiz Augusto von Dentz
2012-03-02 8:55 ` David Miller
2012-03-02 9:27 ` Javier Martinez Canillas
2012-03-02 9:39 ` David Miller
2012-03-02 13:13 ` Eric Dumazet
2012-03-02 16:34 ` Javier Martinez Canillas
2012-03-02 17:08 ` Alan Cox
2012-03-05 8:38 ` Luiz Augusto von Dentz
2012-03-05 14:05 ` Martin Mares
2012-03-05 15:11 ` Javier Martinez Canillas
2012-03-05 15:49 ` Martin Mares
2012-03-05 18:55 ` David Lamparter
2012-03-02 10:08 ` Luiz Augusto von Dentz
2012-03-03 12:20 ` Martin Mares
2012-03-02 22:19 ` david
2012-03-01 12:57 ` Luiz Augusto von Dentz
2012-03-01 20:42 ` David Miller
2012-03-01 14:25 Erik Hugne
2012-03-01 17:18 ` Rodrigo Moya
2012-03-02 7:01 ` Ying Xue
[not found] ` <4F506ABC.8050807@windriver.com>
2012-03-05 15:49 ` Erik Hugne
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