Date: Tue, 21 Apr 2015 14:56:32 +0200
From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To: Jiri Kosina <jkosina@suse.cz>
Cc: One Thousand Gnomes <gnomes@lxorguk.ukuu.org.uk>,
        Andy Lutomirski <luto@amacapital.net>,
        Richard Weinberger <richard@nod.at>,
        David Herrmann <dh.herrmann@gmail.com>,
        Linus Torvalds <torvalds@linux-foundation.org>,
        Steven Rostedt <rostedt@goodmis.org>,
        Al Viro <viro@zeniv.linux.org.uk>, Borislav Petkov <bp@alien8.de>,
        Andrew Morton <akpm@linux-foundation.org>,
        Arnd Bergmann <arnd@arndb.de>,
        "Eric W. Biederman" <ebiederm@xmission.com>,
        Tom Gundersen <teg@jklm.no>,
        "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
        Daniel Mack <daniel@zonque.org>, Djalal Harouni <tixxdz@opendz.org>
Subject: Re: [GIT PULL] kdbus for 4.1-rc1
Message-ID: <20150421125632.GA7294@kroah.com>
References: <CA+55aFzrzrJMuqdBB5=B8wG7eWtFDvViEEBG9xbC10pwyCio8A@mail.gmail.com>
 <CANq1E4TPtAJpbHnvsmCig7U+4k_dqk4wW-Q6X82uWDXa=RkFcQ@mail.gmail.com>
 <CAFLxGvw0Hwh5Vn474LkqKXC9EBOXmf4mPE25ojPjyFw1B9RE_Q@mail.gmail.com>
 <20150420205638.GA3015@kroah.com>
 <55356CC1.1040301@nod.at>
 <20150420214651.GA4215@kroah.com>
 <CALCETrUhaKqteMaptE0X+BYfeRmNBkiMZXEuV1vRb+MXOg6cDw@mail.gmail.com>
 <20150421103519.5b0de5ea@lxorguk.ukuu.org.uk>
 <20150421105123.GB5579@kroah.com>
 <alpine.LNX.2.00.1504211255110.3695@pobox.suse.cz>
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
In-Reply-To: <alpine.LNX.2.00.1504211255110.3695@pobox.suse.cz>
User-Agent: Mutt/1.5.23 (2014-03-12)
Sender: linux-kernel-owner@vger.kernel.org
Content-Length: 1796
Lines: 37

On Tue, Apr 21, 2015 at 01:03:59PM +0200, Jiri Kosina wrote:
> On Tue, 21 Apr 2015, Greg Kroah-Hartman wrote:
> 
> > > We do need something for the multicast messaging. Whether that's
> > > supporting AF_LOCAL, SOCK_RDP with multicast or something else (POSIX
> > > message queue extensions ?). There's no real IP layer reliable ordered
> > > multicast delivery system that is low latency and lightweight because
> > > once it hits real networks it changes from a hard problem into a
> > > seriously hard problem because of multicast implosions and the like.
> > 
> > This was attempted in the past with AF_DBUS, but the networking
> > maintainers rightfully pointed out that the model there did not work.
> 
> BTW, I don't think this has been brought up in this discussion yet ... 
> please correct me if I am wrong, my memory is very faint here (*), but 
> wasn't the main objection to AF_BUS that defining what happens when one of 
> the subscribed receivers disconnects is a policy matter, and as such 
> belongs to userspace (which wasn't the case with the submitted AF_BUS 
> implementation)?
> 
> Was that considered unfixable and AF_BUS consequently given up because of 
> this?

I think it was one of the reasons, I seem to remember many more.  At
that time, I had lunch with David Miller and he told me a few specific
reasons along those lines, and that it just wasn't going to work as a
network protocol at all, and to not try that method anymore, but
instead, do it as a specific IPC interface, as has been done here :)

thanks,

greg k-h
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/