Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932474AbcCPQgt (ORCPT ); Wed, 16 Mar 2016 12:36:49 -0400 Received: from mail-ig0-f179.google.com ([209.85.213.179]:37439 "EHLO mail-ig0-f179.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752927AbcCPQgr (ORCPT ); Wed, 16 Mar 2016 12:36:47 -0400 MIME-Version: 1.0 In-Reply-To: <56E97FD7.9020007@redhat.com> References: <20160316041717.GJ17997@ZenIV.linux.org.uk> <56E97FD7.9020007@redhat.com> Date: Wed, 16 Mar 2016 09:36:46 -0700 X-Google-Sender-Auth: 01lytbl8gZN_keRV0WaFowF5fEM Message-ID: Subject: Re: [WTF] utterly tasteless ABI in hfi1 (around ->write()/->write_iter()) From: Linus Torvalds To: Doug Ledford Cc: Al Viro , Mike Marciniszyn , "linux-rdma@vger.kernel.org" , linux-fsdevel , Linux Kernel Mailing List , Dennis Dalessandro , ira weiny , Jubin John 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: 1156 Lines: 25 On Wed, Mar 16, 2016 at 8:46 AM, Doug Ledford wrote: > > If we want to maintain back compatibility, then the qib driver has to > maintain this interface. We could possibly do a new one as well, but we > can't remove this one. We've broken more important driver ABI's before - all the nasty X stuff. Now, the X people did learn their lesson, and it hasn't happened lately (thank Gods!), but quite frankly, some shit-for-brains hardware-specific config interface for a rdma device that basically nobody uses is a _lot_ less important than X ever was. So I don't care one whit if we break it, and it's not the kind of backwards compatibility the kernel should worry about. There are exactly zero regular users of this interface. I assume that people who use this thing are *so* deeply technical that they can take care of themselves. And it really is a completely broken interface. I might be proven wrong, and somebody's dear old grandma ends up complaining about a new kernel breaking her configuration, and in that case we'd have to revert anything that causes that breakage. But I suspect I'm not wrong. Linus