From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1750970AbbGaEBS (ORCPT ); Fri, 31 Jul 2015 00:01:18 -0400 Received: from mail.linuxfoundation.org ([140.211.169.12]:41622 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750724AbbGaEBS (ORCPT ); Fri, 31 Jul 2015 00:01:18 -0400 Date: Thu, 30 Jul 2015 21:01:15 -0700 From: Greg KH To: Andy Lutomirski Cc: cee1 , LKML , Lennart Poettering , David Herrmann , One Thousand Gnomes Subject: Re: Revisit AF_BUS: is it a better way to implement KDBUS? Message-ID: <20150731040115.GC9785@kroah.com> References: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.23+102 (2ca89bed6448) (2014-03-12) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Jul 30, 2015 at 11:12:44AM -0700, Andy Lutomirski wrote: > On Thu, Jul 30, 2015 at 6:09 AM, cee1 wrote: > > Hi all, > > > > I'm interested in the idea of AF_BUS. > > > > There have already been varies discussions about it: > > * Missing the AF_BUS - https://lwn.net/Articles/504970/ > > * Kroah-Hartman: AF_BUS, D-Bus, and the Linux kernel - > > http://lwn.net/Articles/537021/ > > * presentation-kdbus - > > https://github.com/gregkh/presentation-kdbus/blob/master/kdbus.txt > > * Re: [GIT PULL] kdbus for 4.1-rc1 - https://lwn.net/Articles/641278/ > > * The kdbuswreck - https://lwn.net/Articles/641275/ > > > > I'm wondering whether it is a better way, that is, a general mechanism > > to implement varies __Bus__ orientated IPCs, such as Binder[1], > > DBus[2], etc. > > I find myself wondering whether an in-kernel *bus* is a good idea at > all. Creating a bus that unprivileged programs are allowed to > broadcast on (which is kind of the point) opens up big cans of worms. > Namely: what happens when producers produce data faster than the > consumers consume it? Keep in mind that, with a bus, this scales > pretty badly. Each producer's sends are multiplied by the number of > participants. > > At some point soon, I'm planning on playing with Fedora Rawhide with > kdbus. Anything's possible (maybe), but I'd be rather surprised if it > holds up under abuse of the bus. Just boot Fedora Rawhide with "kdbus=1" on the kernel command line and you should be set. If not, please let the kdbus developers know. thanks, greg k-h