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Date:   Fri, 28 Jan 2022 10:21:38 -0400
From:   Jason Gunthorpe <jgg@ziepe.ca>
To:     Logan Gunthorpe <logang@deltatee.com>
Cc:     linux-kernel@vger.kernel.org, linux-nvme@lists.infradead.org,
        linux-block@vger.kernel.org, linux-pci@vger.kernel.org,
        linux-mm@kvack.org, iommu@lists.linux-foundation.org,
        Stephen Bates <sbates@raithlin.com>,
        Christoph Hellwig <hch@lst.de>,
        Dan Williams <dan.j.williams@intel.com>,
        Christian =?utf-8?B?S8O2bmln?= <christian.koenig@amd.com>,
        John Hubbard <jhubbard@nvidia.com>,
        Don Dutile <ddutile@redhat.com>,
        Matthew Wilcox <willy@infradead.org>,
        Daniel Vetter <daniel.vetter@ffwll.ch>,
        Jakowski Andrzej <andrzej.jakowski@intel.com>,
        Minturn Dave B <dave.b.minturn@intel.com>,
        Jason Ekstrand <jason@jlekstrand.net>,
        Dave Hansen <dave.hansen@linux.intel.com>,
        Xiong Jianxin <jianxin.xiong@intel.com>,
        Bjorn Helgaas <helgaas@kernel.org>,
        Ira Weiny <ira.weiny@intel.com>,
        Robin Murphy <robin.murphy@arm.com>,
        Martin Oliveira <martin.oliveira@eideticom.com>,
        Chaitanya Kulkarni <ckulkarnilinux@gmail.com>,
        Ralph Campbell <rcampbell@nvidia.com>,
        Alex Sierra <alex.sierra@amd.com>
Subject: Re: [PATCH v5 02/24] mm: remove extra ZONE_DEVICE struct page
 refcount
Message-ID: <20220128142138.GU8034@ziepe.ca>
References: <20220128002614.6136-1-logang@deltatee.com>
 <20220128002614.6136-3-logang@deltatee.com>
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On Thu, Jan 27, 2022 at 05:25:52PM -0700, Logan Gunthorpe wrote:
> From: Ralph Campbell <rcampbell@nvidia.com>
> 
> ZONE_DEVICE struct pages have an extra reference count that complicates the
> code for put_page() and several places in the kernel that need to check the
> reference count to see that a page is not being used (gup, compaction,
> migration, etc.). Clean up the code so the reference count doesn't need to
> be treated specially for ZONE_DEVICE.
> 
> [logang: dropped no longer used section from mm.h including
>  page_is_devmap_managed, rebased on v5.17-rc1 (possibly poorly)]
> Signed-off-by: Ralph Campbell <rcampbell@nvidia.com>
> Signed-off-by: Alex Sierra <alex.sierra@amd.com>
> Signed-off-by: Logan Gunthorpe <logang@deltatee.com>
> Reviewed-by: Christoph Hellwig <hch@lst.de>
> ---
>  arch/powerpc/kvm/book3s_hv_uvmem.c     |  2 +-
>  drivers/gpu/drm/nouveau/nouveau_dmem.c |  2 +-
>  fs/dax.c                               |  4 +-
>  include/linux/dax.h                    |  2 +-
>  include/linux/memremap.h               |  7 +--
>  include/linux/mm.h                     | 44 ----------------
>  lib/test_hmm.c                         |  2 +-
>  mm/internal.h                          |  8 +++
>  mm/memcontrol.c                        |  6 +--
>  mm/memremap.c                          | 70 +++++++-------------------
>  mm/migrate.c                           |  5 --
>  mm/page_alloc.c                        |  3 ++
>  mm/swap.c                              | 45 ++---------------
>  13 files changed, 46 insertions(+), 154 deletions(-)

This patch still can't be applied until the FSDAX issues are solved,
right? See my remarks the last time it was posted..

Jason