From: Eric Dumazet <eric.dumazet@gmail.com>
To: Javier Martinez Canillas <javier.martinez@collabora.co.uk>
Cc: Rodrigo Moya <rodrigo.moya@collabora.co.uk>,
David Laight <David.Laight@ACULAB.COM>,
David Miller <davem@davemloft.net>,
javier@collabora.co.uk, 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: Thu, 01 Mar 2012 08:00:40 -0800 [thread overview]
Message-ID: <1330617640.2465.78.camel@edumazet-laptop> (raw)
In-Reply-To: <4F4F7FFB.6010608@collabora.co.uk>
Le jeudi 01 mars 2012 à 14:56 +0100, Javier Martinez Canillas a écrit :
> We could use AF_INET multicast on a local machine but we need some
> ordering and control flow requirements that are not guaranteed on UDP
> multicast over IP. That's why we thought to add a new address family
> AF_MCAST.
>
It seems application logic and complexity pushed into kernel, for a very
single user (even if used in a lot of products) : D-Bus
> To make it a general local multicast solution and not being too specific
> we added some flags to control its behavior like
> MCAST_MREQ_DROP_WHEN_FULL to decide to either block the sender or drop
> the packet when one receiver has its queue full.
I am only wondering how many lines this is going to add in kernel for a
complete implementation, given your performance expectations, flow
control, reliability, not counting all security issues (ancillary
messages and so on)
In case of IP_MULTICAST_LOOP, we could allow the sender to sleep if
receiver queue is full, with a bit of tweaking in stack (current
implementation uses loopback re-inject, so requires softirq handling).
In fact, we could use a new IP_MULTICAST_LOCAL option, so that sender
processing doesnt trigger a softirq handler at all and is allowed to
sleep if needed. For example skb allocations could use GFP_KERNEL
instead of current GFP_ATOMIC ones in udp mcast .
I dont know, maybe it would be a smaller patch.
next prev parent reply other threads:[~2012-03-01 16:00 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
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 [this message]
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
-- strict thread matches above, loose matches on Subject: below --
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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