Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752641AbaJPXNb (ORCPT ); Thu, 16 Oct 2014 19:13:31 -0400 Received: from mail.linuxfoundation.org ([140.211.169.12]:49594 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750765AbaJPXN3 (ORCPT ); Thu, 16 Oct 2014 19:13:29 -0400 Date: Fri, 17 Oct 2014 01:12:21 +0200 From: Greg Kroah-Hartman To: John Stultz Cc: lkml , devel@driverdev.osuosl.org, Linux API , Santosh Shilimkar , Arve =?iso-8859-1?B?SGr4bm5lduVn?= , Sumit Semwal , Rebecca Schultz Zavin , Christoffer Dall , Anup Patel Subject: Re: [PATCH] staging: android: binder: move to the "real" part of the kernel Message-ID: <20141016231221.GA13592@kroah.com> References: <20141016124741.GA3832@kroah.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.23 (2014-03-12) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Oct 16, 2014 at 10:09:04AM -0700, John Stultz wrote: > On Thu, Oct 16, 2014 at 5:47 AM, Greg Kroah-Hartman > wrote: > > From: Greg Kroah-Hartman > > > > The Android binder code has been "stable" for many years now. No matter > > Well, ignoring the ABI break that landed in the last year. :) As no one noticed, it wasn't a "break" :) > > This was discussed in the Android miniconf at the Plumbers conference. > > If anyone has any objections to this, please let me know, otherwise I'm > > queueing this up for 3.19-rc1 > > So my main concerns/thoughts here are: > > Who is going to maintain this? Has Arve agreed? Do we really need someone to do more work that has been done on it in the past as an official "maintainer"? I'll be glad to do it, as I doubt it will require any time at all. > Are the Android guys comfortable with the ABI stability rules they'll > now face? Just because something is in staging, doesn't mean you don't have to follow the same ABI stability rules as the rest of the kernel. If a change had happened to this code that broke userspace in the past, I would have reverted it. So this should not be anything different from what has been happening inthe past. And the Android developers said they were happy to see this code move into the "real" part of the kernel. > Currently in the android space no one but libbinder should use the > kernel interface. That is correct. If you do that, you deserve all of the pain and suffering and rooted machines you will get. > Can we enforce that no one use this interface out-side of android (To > ensure its one of those "if the abi breaks and no one notices..." edge > cases)? This is the kernel, we can not dictate "use", that's the good part of the GPLv2 :) Again, as no one has done this before, I strongly doubt it will happen in the future. > I'm still hopeful that a libbinder over kdbus will eventually pan out. > I still see having two core IPC mechanisms (even if the use cases are > different in style) as a negative, and I worry this might reduce > motivation to unify things at the lower level. Granted, such work can > still continue, but the incentives do change. Yes, things are going to change in the future, there is work happening here, and there was a presentation at Plumbers about what is going to be coming. But all of the changes will be in new code. Be it kdbus, or something else if that doesn't work out. This existing binder.c file will not be changing at all. This existing ABI, and codebase, is something that we have to maintain forever for those millions of devices out there in the real world today. So as there really is nothing left to do on it, it deserves to be in the main part of the kernel source tree. 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/