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=-2.5 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS,USER_AGENT_MUTT 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 278A7C4360F for ; Tue, 19 Mar 2019 19:05:34 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 021DF2146E for ; Tue, 19 Mar 2019 19:05:33 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727628AbfCSTFc (ORCPT ); Tue, 19 Mar 2019 15:05:32 -0400 Received: from mx1.redhat.com ([209.132.183.28]:60778 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726944AbfCSTFc (ORCPT ); Tue, 19 Mar 2019 15:05:32 -0400 Received: from smtp.corp.redhat.com (int-mx05.intmail.prod.int.phx2.redhat.com [10.5.11.15]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 3CA4B308622A; Tue, 19 Mar 2019 19:05:31 +0000 (UTC) Received: from redhat.com (unknown [10.20.6.236]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 322C26295D; Tue, 19 Mar 2019 19:05:30 +0000 (UTC) Date: Tue, 19 Mar 2019 15:05:28 -0400 From: Jerome Glisse To: Dan Williams Cc: Andrew Morton , Linux MM , Linux Kernel Mailing List , Felix Kuehling , Christian =?iso-8859-1?Q?K=F6nig?= , Ralph Campbell , John Hubbard , Jason Gunthorpe , Alex Deucher Subject: Re: [PATCH 00/10] HMM updates for 5.1 Message-ID: <20190319190528.GA4012@redhat.com> References: <20190313012706.GB3402@redhat.com> <20190313091004.b748502871ba0aa839b924e9@linux-foundation.org> <20190318170404.GA6786@redhat.com> <20190319094007.a47ce9222b5faacec3e96da4@linux-foundation.org> <20190319165802.GA3656@redhat.com> <20190319101249.d2076f4bacbef948055ae758@linux-foundation.org> <20190319171847.GC3656@redhat.com> <20190319174552.GA3769@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: User-Agent: Mutt/1.10.0 (2018-05-17) X-Scanned-By: MIMEDefang 2.79 on 10.5.11.15 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.42]); Tue, 19 Mar 2019 19:05:31 +0000 (UTC) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Mar 19, 2019 at 11:42:00AM -0700, Dan Williams wrote: > On Tue, Mar 19, 2019 at 10:45 AM Jerome Glisse wrote: > > > > On Tue, Mar 19, 2019 at 10:33:57AM -0700, Dan Williams wrote: > > > On Tue, Mar 19, 2019 at 10:19 AM Jerome Glisse wrote: > > > > > > > > On Tue, Mar 19, 2019 at 10:12:49AM -0700, Andrew Morton wrote: > > > > > On Tue, 19 Mar 2019 12:58:02 -0400 Jerome Glisse wrote: > > > [..] > > > > > Also, the discussion regarding [07/10] is substantial and is ongoing so > > > > > please let's push along wth that. > > > > > > > > I can move it as last patch in the serie but it is needed for ODP RDMA > > > > convertion too. Otherwise i will just move that code into the ODP RDMA > > > > code and will have to move it again into HMM code once i am done with > > > > the nouveau changes and in the meantime i expect other driver will want > > > > to use this 2 helpers too. > > > > > > I still hold out hope that we can find a way to have productive > > > discussions about the implementation of this infrastructure. > > > Threatening to move the code elsewhere to bypass the feedback is not > > > productive. > > > > I am not threatening anything that code is in ODP _today_ with that > > patchset i was factering it out so that i could also use it in nouveau. > > nouveau is built in such way that right now i can not use it directly. > > But i wanted to factor out now in hope that i can get the nouveau > > changes in 5.2 and then convert nouveau in 5.3. > > > > So when i said that code will be in ODP it just means that instead of > > removing it from ODP i will keep it there and it will just delay more > > code sharing for everyone. > > The point I'm trying to make is that the code sharing for everyone is > moving the implementation closer to canonical kernel code and use > existing infrastructure. For example, I look at 'struct hmm_range' and > see nothing hmm specific in it. I think we can make that generic and > not build up more apis and data structures in the "hmm" namespace. Right now i am trying to unify driver for device that have can support the mmu notifier approach through HMM. Unify to a superset of driver that can not abide by mmu notifier is on my todo list like i said but it comes after. I do not want to make the big jump in just one go. So i doing thing under HMM and thus in HMM namespace, but once i tackle the larger set i will move to generic namespace what make sense. This exact approach did happen several time already in the kernel. In the GPU sub-system we did it several time. First do something for couple devices that are very similar then grow to a bigger set of devices and generalise along the way. So i do not see what is the problem of me repeating that same pattern here again. Do something for a smaller set before tackling it on for a bigger set. Cheers, Jérôme