From: Alan Cox <alan@lxorguk.ukuu.org.uk>
To: Javier Martinez Canillas <javier.martinez@collabora.co.uk>
Cc: Eric Dumazet <eric.dumazet@gmail.com>,
David Miller <davem@davemloft.net>,
shemminger@vyatta.com, ying.xue@windriver.com,
luiz.dentz@gmail.com, rodrigo.moya@collabora.co.uk,
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,
Marcel Holtmann <marcel@holtmann.org>
Subject: Re: [PATCH 0/10] af_unix: add multicast and filtering features to AF_UNIX
Date: Fri, 2 Mar 2012 17:08:23 +0000 [thread overview]
Message-ID: <20120302170823.7117821b@pyramind.ukuu.org.uk> (raw)
In-Reply-To: <4F50F6AA.9050909@collabora.co.uk>
> 2- The transport layer used by D-bus is not performance sensitive
> basically due:
>
> a) high number of context switches required to send messages between peer.
This is a user space design issue. The fact dbus wakes up so much
stuff wants fixing at the dbus level.
> b) the D-bus daemon doing the routing and being a bottleneck of the whole.
This is a userspace design issue.
> c) amount of messages copied between kernel space and user space.
This is mostly a userspace design issue and fixing a would fix much of c
because you wouldn't keep sending people crap they didn't need.
You've already got multicast facilities in kernel (if dbus must work by
shouting not state change subscription like saner setups), and you've got
BPF filtering facilities to try and cure some of the wakeups even doing
multicast.
Beyond that I don't see what the kernel can do given its mostly an
architectural problem.
Your model appears to be "since its causing enormous amounts of work we
should do the work faster". The right model would appear to me to be "We
shouldn't cause enormous amounts of work"
Alan
next prev parent reply other threads:[~2012-03-02 17:06 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
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 [this message]
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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