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=DKIM_SIGNED,DKIM_VALID, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=no 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 4E3CCC0650E for ; Thu, 4 Jul 2019 23:38:05 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 1102D205ED for ; Thu, 4 Jul 2019 23:38:04 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=intel-com.20150623.gappssmtp.com header.i=@intel-com.20150623.gappssmtp.com header.b="ftzysFAg" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727651AbfGDXiD (ORCPT ); Thu, 4 Jul 2019 19:38:03 -0400 Received: from mail-oi1-f194.google.com ([209.85.167.194]:41873 "EHLO mail-oi1-f194.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727142AbfGDXiD (ORCPT ); Thu, 4 Jul 2019 19:38:03 -0400 Received: by mail-oi1-f194.google.com with SMTP id g7so5915320oia.8 for ; Thu, 04 Jul 2019 16:38:02 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=intel-com.20150623.gappssmtp.com; s=20150623; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=ve/CczmjDTp62IiyOlOME0RVKS5HfvyxwnJvsVLm4Vs=; b=ftzysFAgpNAb+BruhLNH0hJPG1+DZJH5fW47QFP2ZCCrJsWY0QiqCN33vLIdmP+YKX oYjFGqBNFdAiE67/Scf00vlp73/xqc9pUOTQqv50+CArtatDE9N0E1fmMn6a6b4TXgvC b4ikeLch0hVf8zFQYSEq1w3vTKY09hc+kjsVZV/qqSlPyxPEUIxUQ7KsfqcwWe9BrcAA v/Qn7UXw1I9f8vsa2e7SuNV9MVKpvVtW0GhCb8C3HKqRROUiumhwmxjXK1mvWegh7J9t v+AIy6jg8Of0NKSl5vCY5SL/L+7uGHiv+8rWcdQo5jq8sjpRw09XucLUw0n59f/fPRH+ PPcw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=ve/CczmjDTp62IiyOlOME0RVKS5HfvyxwnJvsVLm4Vs=; b=a6ei/cpno/s8wnMV7RPP0TpXX2SYQtHDqMqQkqiFOstUxB9E69BriwOmR00btTSy8a X5813aPRPfKNCb+cth15649XRZWcIGYffxdXTxhJ0Hp7ww+lhFTYMPxv/xjw/V/ZieZ8 jJJiQSDSUdv1caRIIIv1Ca0OhKaSekP06U/dYF4/jat8xj8u+fQr0COrOokgZS0lRSaY FSJNh2b7Kg4GKiyA45pxHDaYgmIcugo7U/dCnVZfOWNkKOtLaOzpWvV0OnaTL/JHLQu6 3aeK0SDoetOa/Zxim2W87NmCcHykJKIzTXLx0FDr07xXNjkTAPOp+UazwGayGRpCsEQ6 wInw== X-Gm-Message-State: APjAAAWjIKRRap0WfCQ78WGZrfcpE4f6JNSGAKw4qJlXUtYPfvUc0+Za ZYbjQAlbDT6elc4O55iE0aWV35wWFTK3DvVIJYbdKQ== X-Google-Smtp-Source: APXvYqxPvl0JaE/xctjYrnEPxDDTTNAKohKZCdbZNul+YnSwqo3/7CHb/acC/vbGgVjEA6Xdvr5WpUQKmbNeFnXQ/uE= X-Received: by 2002:aca:ba02:: with SMTP id k2mr441491oif.70.1562283482013; Thu, 04 Jul 2019 16:38:02 -0700 (PDT) MIME-Version: 1.0 References: <20190626073533.GA24199@infradead.org> <20190626123139.GB20635@lakrids.cambridge.arm.com> <20190626153829.GA22138@infradead.org> <20190626154532.GA3088@mellanox.com> <20190626203551.4612e12be27be3458801703b@linux-foundation.org> <20190704115324.c9780d01ef6938ab41403bf9@linux-foundation.org> <20190704195934.GA23542@mellanox.com> In-Reply-To: <20190704195934.GA23542@mellanox.com> From: Dan Williams Date: Thu, 4 Jul 2019 16:37:51 -0700 Message-ID: Subject: Re: [PATCH v3 0/4] Devmap cleanups + arm64 support To: Jason Gunthorpe Cc: Andrew Morton , Christoph Hellwig , Mark Rutland , Robin Murphy , "linux-mm@kvack.org" , "will.deacon@arm.com" , "catalin.marinas@arm.com" , "anshuman.khandual@arm.com" , "linux-arm-kernel@lists.infradead.org" , "linux-kernel@vger.kernel.org" , Michal Hocko Content-Type: text/plain; charset="UTF-8" Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Jul 4, 2019 at 12:59 PM Jason Gunthorpe wrote: > > On Thu, Jul 04, 2019 at 11:53:24AM -0700, Andrew Morton wrote: > > On Wed, 26 Jun 2019 20:35:51 -0700 Andrew Morton wrote: > > > > > > Let me know and I can help orchestate this. > > > > > > Well. Whatever works. In this situation I'd stage the patches after > > > linux-next and would merge them up after the prereq patches have been > > > merged into mainline. Easy. > > > > All right, what the hell just happened? > > Christoph's patch series for the devmap & hmm rework finally made it > into linux-next, sorry, it took quite a few iterations on the list to > get all the reviews and tests, and figure out how to resolve some > other conflicting things. So it just made it this week. > > Recall, this is the patch series I asked you about routing a few weeks > ago, as it really exceeded the small area that hmm.git was supposed to > cover. I think we are both caught off guard how big the conflict is! > > > A bunch of new material has just been introduced into linux-next. > > I've partially unpicked the resulting mess, haven't dared trying to > > compile it yet. To get this far I'll need to drop two patch series > > and one individual patch: > > > mm-clean-up-is_device__page-definitions.patch > > mm-introduce-arch_has_pte_devmap.patch > > arm64-mm-implement-pte_devmap-support.patch > > arm64-mm-implement-pte_devmap-support-fix.patch > > This one we discussed, and I thought we agreed would go to your 'stage > after linux-next' flow (see above). I think the conflict was minor > here. > > > mm-sparsemem-introduce-struct-mem_section_usage.patch > > mm-sparsemem-introduce-a-section_is_early-flag.patch > > mm-sparsemem-add-helpers-track-active-portions-of-a-section-at-boot.patch > > mm-hotplug-prepare-shrink_zone-pgdat_span-for-sub-section-removal.patch > > mm-sparsemem-convert-kmalloc_section_memmap-to-populate_section_memmap.patch > > mm-hotplug-kill-is_dev_zone-usage-in-__remove_pages.patch > > mm-kill-is_dev_zone-helper.patch > > mm-sparsemem-prepare-for-sub-section-ranges.patch > > mm-sparsemem-support-sub-section-hotplug.patch > > mm-document-zone_device-memory-model-implications.patch > > mm-document-zone_device-memory-model-implications-fix.patch > > mm-devm_memremap_pages-enable-sub-section-remap.patch > > libnvdimm-pfn-fix-fsdax-mode-namespace-info-block-zero-fields.patch > > libnvdimm-pfn-stop-padding-pmem-namespaces-to-section-alignment.patch > > Dan pointed to this while reviewing CH's series and said the conflicts > would be manageable, but they are certainly larger than I expected! > > This series is the one that seems to be the really big trouble. I > already checked all the other stuff that Stephen resolved, and it > looks OK and managable. Just this one conflict with kernel/memremap.c > is beyond me. > > What approach do you want to take to go forward? Here are some thoughts: > > CH has said he is away for the long weekend, so the path that involves > the fewest people is if Dan respins the above on linux-next and it > goes later with the arm patches above, assuming defering it for now > has no other adverse effects on -mm. > > Pushing CH's series to -mm would need a respin on top of Dan's series > above and would need to carry along the whole hmm.git (about 44 > patches). Signs are that this could be managed with the code currently > in the GPU trees. > > If we give up on CH's series the hmm.git will not have conflicts, > however we just kick the can to the next merge window where we will be > back to having to co-ordinate amd/nouveau/rdma git trees and -mm's > patch workflow - and I think we will be worse off as we will have > totally given up on a git based work flow for this. :( I think the problem would be resolved going forward post-v5.3 since we won't have two tress managing kernel/memremap.c. This cycle however there is a backlog of kernel/memremap.c changes in -mm.