Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756028AbbDVDMP (ORCPT ); Tue, 21 Apr 2015 23:12:15 -0400 Received: from mail-qg0-f42.google.com ([209.85.192.42]:35004 "EHLO mail-qg0-f42.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755800AbbDVDMO (ORCPT ); Tue, 21 Apr 2015 23:12:14 -0400 MIME-Version: 1.0 In-Reply-To: <1429667524.3948.72.camel@thorin> References: <20150420205638.GA3015@kroah.com> <55356CC1.1040301@nod.at> <20150421090721.GB20838@sig21.net> <1429667524.3948.72.camel@thorin> From: Havoc Pennington Date: Tue, 21 Apr 2015 23:11:40 -0400 X-Google-Sender-Auth: E772wLBNcOLcvA_gFV7ncrMnX1g Message-ID: Subject: Re: [GIT PULL] kdbus for 4.1-rc1 To: Bernd Petrovitsch Cc: Johannes Stezenbach , Richard Weinberger , Greg Kroah-Hartman , David Herrmann , Linus Torvalds , Steven Rostedt , One Thousand Gnomes , Jiri Kosina , Al Viro , Borislav Petkov , Andy Lutomirski , Andrew Morton , Arnd Bergmann , "Eric W. Biederman" , Tom Gundersen , "linux-kernel@vger.kernel.org" , Daniel Mack , Djalal Harouni Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2002 Lines: 43 On Tue, Apr 21, 2015 at 9:51 PM, Bernd Petrovitsch wrote: > Hi all! > > On Die, 2015-04-21 at 09:37 -0400, Havoc Pennington wrote: > [...] >> This has long been sort of the 'party line' and I've told many people >> this on the dbus mailing list over the years (almost exactly what you >> just said - that for performance-critical cases they should open a >> direct socket or use something else or whatever). Usually this makes >> app developers a little cranky because something that was going to be >> easy in their mind just got harder. > > Perhaps these developers should rethink the design and protocols of > their apps - or pay the price for a stupid design which relies on heavy > IPC traffic (and usually - sooner or later - heavy network traffic). > Or - at least - deliver a (technical!) proof why this isn't feasible. > > The case of "patching the kernel to lie about the kernel's command line" > just because some ill-designed user-space daemon misused it" was bad > enough and the above smells quite similarly. > I don't think it's ridiculous that app developers try the clean, simple solution first (use one IPC for everything) and only optimize once they discover they need to. If dbus were faster, many of these designs might not be stupid and might not be a mis-use. And the app might delete a lot of code, which is a plus for anyone using that app. More code = more bugs after all. I grant you that some apps have bad code, but I don't think it's my job to punish them by making things slow on purpose. I only made things slow because I didn't know a way to make them fast without sacrificing a more important goal, but it was never ideal. The kdbus developers have proposed a way out of the tradeoff. Havoc -- 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/