Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754254AbZFSTUk (ORCPT ); Fri, 19 Jun 2009 15:20:40 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751575AbZFSTUd (ORCPT ); Fri, 19 Jun 2009 15:20:33 -0400 Received: from smtp-out.google.com ([216.239.45.13]:52041 "EHLO smtp-out.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751370AbZFSTUd convert rfc822-to-8bit (ORCPT ); Fri, 19 Jun 2009 15:20:33 -0400 DomainKey-Signature: a=rsa-sha1; s=beta; d=google.com; c=nofws; q=dns; h=mime-version:in-reply-to:references:date:message-id:subject:from:to: cc:content-type:content-transfer-encoding:x-system-of-record; b=yzJ7X1K/yJ39OtCY8dYc4Th/Bb5nzlsLnGci8vJkiJ3OkclPxHU71C5X0lKnlv4CG pXD+NTwClR3C6fdCIUlWg== MIME-Version: 1.0 In-Reply-To: <1245274308.5982.268.camel@desktop> References: <1244832678-30329-1-git-send-email-dwalker@fifo99.com> <4A380494.6030506@goop.org> <1245249469.5982.251.camel@desktop> <4A390B9A.40806@goop.org> <1245254936.5982.261.camel@desktop> <4A391A54.7000109@goop.org> <1245274308.5982.268.camel@desktop> Date: Fri, 19 Jun 2009 12:20:31 -0700 Message-ID: Subject: Re: [PATCH 1/6] staging: android: binder: Remove some funny && usage From: Brian Swetland To: Daniel Walker Cc: =?UTF-8?B?QXJ2ZSBIasO4bm5ldsOlZw==?= , Jeremy Fitzhardinge , Greg Kroah-Hartman , linux-kernel@vger.kernel.org Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8BIT X-System-Of-Record: true Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1667 Lines: 34 2009/6/17 Daniel Walker : > On Wed, 2009-06-17 at 14:26 -0700, Arve Hjønnevåg wrote: >> On Wed, Jun 17, 2009 at 9:31 AM, Jeremy Fitzhardinge wrote: >> > On 06/17/09 09:08, Daniel Walker wrote: >> ... >> > Also, what its usermode ABI is, how stable it is, whether its generally >> > useful, does it have glibc/other library support, etc.  Would you ever want >> > to use this in a non-Android context? >> >> You could use this in a non-android context, but the abi is not >> stable. There is some documentaion of the current user space api at >> http://developer.android.com/reference/android/os/IBinder.html. You >> can also find more information at http://www.open-binder.org/ which is >> where the api came from. > > Why does all this need to be done in the kernel? Couldn't any of the > current IPC mechanisms be re-used to accomplish this? Arve can probably go into more detail here, but I believe the two notable properties of the binder that are not present in existing IPC mechanisms in the kernel (that I'm aware of) are: - avoiding copies by having the kernel copy from the writer into a ring buffer in the reader's address space directly (allocating space if necessary) - managing the lifespan of proxied remoted userspace objects that can be shared and passed between processes (upon which the userspace binder library builds its remote reference counting model) Brian -- 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/