From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-1.0 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_PASS autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id C8FC0C43381 for ; Thu, 7 Mar 2019 17:46:59 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 8D7FB20854 for ; Thu, 7 Mar 2019 17:46:59 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1551980819; bh=1RSAAoDl+MfB8HGRc1Opl1CrXXA7wmKimpQdk1qa2rU=; h=Date:From:To:Cc:Subject:In-Reply-To:References:List-ID:From; b=1GYriN7yFaL0k8uu2BkfiawwHxEiPZyogTnjp0/+OwwOXwlUP2ZJveyvb9m2TwWen +0/HFz5bK3RaE1ikOwA+NhQLyzxSBZem7EEF/O+EgZbF4vBaAMeEbtR2Q6WHv9WPzt 6t4ZCq7pFboHMrOlfj26TQs00AO0aHdsmB5EVSe4= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726960AbfCGRq5 (ORCPT ); Thu, 7 Mar 2019 12:46:57 -0500 Received: from mail.linuxfoundation.org ([140.211.169.12]:36516 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726943AbfCGRq4 (ORCPT ); Thu, 7 Mar 2019 12:46:56 -0500 Received: from akpm3.svl.corp.google.com (unknown [104.133.8.65]) by mail.linuxfoundation.org (Postfix) with ESMTPSA id 17DE1C139; Thu, 7 Mar 2019 17:46:55 +0000 (UTC) Date: Thu, 7 Mar 2019 09:46:54 -0800 From: Andrew Morton To: Dan Williams Cc: Jerome Glisse , Linux MM , Linux Kernel Mailing List , Ralph Campbell , John Hubbard , linux-fsdevel Subject: Re: [PATCH 09/10] mm/hmm: allow to mirror vma of a file on a DAX backed filesystem Message-Id: <20190307094654.35391e0066396b204d133927@linux-foundation.org> In-Reply-To: References: <20190129165428.3931-10-jglisse@redhat.com> <20190129193123.GF3176@redhat.com> <20190129212150.GP3176@redhat.com> <20190130030317.GC10462@redhat.com> <20190130183616.GB5061@redhat.com> <20190131041641.GK5061@redhat.com> <20190305141635.8134e310ba7187bc39532cd3@linux-foundation.org> X-Mailer: Sylpheed 3.6.0 (GTK+ 2.24.31; x86_64-pc-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, 5 Mar 2019 20:20:10 -0800 Dan Williams wrote: > My hesitation would be drastically reduced if there was a plan to > avoid dangling unconsumed symbols and functionality. Specifically one > or more of the following suggestions: > > * EXPORT_SYMBOL_GPL on all exports to avoid a growing liability > surface for out-of-tree consumers to come grumble at us when we > continue to refactor the kernel as we are wont to do. The existing patches use EXPORT_SYMBOL() so that's a sticking point. Jerome, what would happen is we made these EXPORT_SYMBOL_GPL()? > * A commitment to consume newly exported symbols in the same merge > window, or the following merge window. When that goal is missed revert > the functionality until such time that it can be consumed, or > otherwise abandoned. It sounds like we can tick this box. > * No new symbol exports and functionality while existing symbols go unconsumed. Unsure about this one?