From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753270AbeEVVb1 (ORCPT ); Tue, 22 May 2018 17:31:27 -0400 Received: from mail.linuxfoundation.org ([140.211.169.12]:49892 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753007AbeEVVbX (ORCPT ); Tue, 22 May 2018 17:31:23 -0400 Date: Tue, 22 May 2018 14:31:21 -0700 From: Andrew Morton To: Christoph Hellwig Cc: Dan Williams , =?ISO-8859-1?Q?J=E9r=F4me?= Glisse , Logan Gunthorpe , linux-mm@kvack.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH 5/5] mm, hmm: mark hmm_devmem_{add, add_resource} EXPORT_SYMBOL_GPL Message-Id: <20180522143121.54d4ebced511277b923d31ba@linux-foundation.org> In-Reply-To: <20180522063236.GE7925@lst.de> References: <152694211402.5484.2277538346144115181.stgit@dwillia2-desk3.amr.corp.intel.com> <152694214044.5484.1081005408496303826.stgit@dwillia2-desk3.amr.corp.intel.com> <20180522063236.GE7925@lst.de> 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 List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, 22 May 2018 08:32:36 +0200 Christoph Hellwig wrote: > On Mon, May 21, 2018 at 03:35:40PM -0700, Dan Williams wrote: > > The routines hmm_devmem_add(), and hmm_devmem_add_resource() are small > > wrappers around devm_memremap_pages(). The devm_memremap_pages() > > interface is a subset of the hmm functionality which has more and deeper > > ties into the kernel memory management implementation. It was an > > oversight that these symbols were not marked EXPORT_SYMBOL_GPL from the > > outset due to how they originally copied (and now reuse) > > devm_memremap_pages(). > > If we end up keeping this code: absolutely. Then again I think without > an actual user this should have never been merged, and should be removed > until one shows up. > It wasn't simple. Quite a lot of manufacturers were (are?) developing quite complex driver code which utilizes hmm. Merging hmm to give a stable target for that development and in the expectation that those things would be coming along was a risk and I don't think we yet know the outcome. Jerome, are you able to provide any updates on all of this?