+ mm-remove-a-pointless-config_zone_device-check-in-memremap_pages.patch added to -mm tree

[Andrew Morton <akpm@linux-foundation.org>]

The patch titled
     Subject: mm: remove a pointless CONFIG_ZONE_DEVICE check in memremap_pages
has been added to the -mm tree.  Its filename is
     mm-remove-a-pointless-config_zone_device-check-in-memremap_pages.patch

This patch should soon appear at
    https://ozlabs.org/~akpm/mmots/broken-out/mm-remove-a-pointless-config_zone_device-check-in-memremap_pages.patch
and later at
    https://ozlabs.org/~akpm/mmotm/broken-out/mm-remove-a-pointless-config_zone_device-check-in-memremap_pages.patch

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------------------------------------------------------
From: Christoph Hellwig <hch@lst.de>
Subject: mm: remove a pointless CONFIG_ZONE_DEVICE check in memremap_pages

Patch series "start sorting out the ZONE_DEVICE refcount mess", v2.

This series removes the offset by one refcount for ZONE_DEVICE pages that
are freed back to the driver owning them, which is just device private
ones for now, but also the planned device coherent pages and the ehanced
p2p ones pending.

It does not address the fsdax pages yet, which will be attacked in a
follow on series.


This patch (of 27):

memremap.c is only built when CONFIG_ZONE_DEVICE is set, so remove
the superflous extra check.

Link: https://lkml.kernel.org/r/20220210072828.2930359-1-hch@lst.de
Link: https://lkml.kernel.org/r/20220210072828.2930359-2-hch@lst.de
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Logan Gunthorpe <logang@deltatee.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com>
Reviewed-by: Muchun Song <songmuchun@bytedance.com>
Reviewed-by: Dan Williams <dan.j.williams@intel.com>
Reviewed-by: Miaohe Lin <linmiaohe@huawei.com>
Tested-by: "Sierra Guiza, Alejandro (Alex)" <alex.sierra@amd.com>
Cc: Felix Kuehling <Felix.Kuehling@amd.com>
Cc: Alex Deucher <alexander.deucher@amd.com>
Cc: Christian Knig <christian.koenig@amd.com>
Cc: "Pan, Xinhui" <Xinhui.Pan@amd.com>
Cc: Ben Skeggs <bskeggs@redhat.com>
Cc: Karol Herbst <kherbst@redhat.com>
Cc: Lyude Paul <lyude@redhat.com>
Cc: Alistair Popple <apopple@nvidia.com>
Cc: Ralph Campbell <rcampbell@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---


--- a/mm/memremap.c~mm-remove-a-pointless-config_zone_device-check-in-memremap_pages
+++ a/mm/memremap.c
@@ -349,8 +349,7 @@ void *memremap_pages(struct dev_pagemap
 		}
 		break;
 	case MEMORY_DEVICE_FS_DAX:
-		if (!IS_ENABLED(CONFIG_ZONE_DEVICE) ||
-		    IS_ENABLED(CONFIG_FS_DAX_LIMITED)) {
+		if (IS_ENABLED(CONFIG_FS_DAX_LIMITED)) {
 			WARN(1, "File system DAX not supported\n");
 			return ERR_PTR(-EINVAL);
 		}
_

Patches currently in -mm which might be from hch@lst.de are

mm-unexport-page_init_poison.patch
mm-remove-a-pointless-config_zone_device-check-in-memremap_pages.patch
mm-remove-the-__kernel__-guard-from-linux-mmh.patch
mm-remove-pointless-includes-from-linux-hmmh.patch
mm-move-free_devmap_managed_page-to-memremapc.patch
mm-simplify-freeing-of-devmap-managed-pages.patch
mm-dont-include-linux-memremaph-in-linux-mmh.patch
mm-remove-the-extra-zone_device-struct-page-refcount.patch
fsdax-depend-on-zone_device-fs_dax_limited.patch
mm-generalize-the-pgmap-based-page_free-infrastructure.patch
mm-refactor-check_and_migrate_movable_pages.patch
mm-refactor-the-zone_device-handling-in-migrate_vma_insert_page.patch
mm-refactor-the-zone_device-handling-in-migrate_vma_pages.patch
mm-move-the-migrate_vma_-device-migration-code-into-its-own-file.patch
mm-build-migrate_vma_-for-all-configs-with-zone_device-support.patch
mm-add-zone-device-coherent-type-memory-support.patch
mm-add-device-coherent-vma-selection-for-memory-migration.patch