mm/migrate: remove unnecessary is_zone_device_page() check

Patch series "mm/migrate: preserve soft dirty in remove_migration_pte()".

I happened to notice this from code inspection after seeing Alistair
Popple's patch ("mm/rmap: Fixup copying of soft dirty and uffd ptes").

This patch (of 2):

The check for is_zone_device_page() and is_device_private_page() is
unnecessary since the latter is sufficient to determine if the page is a
device private page.  Simplify the code for easier reading.

Signed-off-by: Ralph Campbell <rcampbell@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Cc: Jerome Glisse <jglisse@redhat.com>
Cc: Alistair Popple <apopple@nvidia.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Jason Gunthorpe <jgg@nvidia.com>
Cc: Bharata B Rao <bharata@linux.ibm.com>
Link: https://lkml.kernel.org/r/20200831212222.22409-1-rcampbell@nvidia.com
Link: https://lkml.kernel.org/r/20200831212222.22409-2-rcampbell@nvidia.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/mm/migrate.c b/mm/migrate.c
index 12f63806d0ac6015f0ef3235d598eb2b792be84f..1d791d4207254213fb408b104f4abd5c6dfda44f 100644 (file)
--- a/mm/migrate.c
+++ b/mm/migrate.c
@@ -246,13 +246,11 @@ static bool remove_migration_pte(struct page *page, struct vm_area_struct *vma,
                else if (pte_swp_uffd_wp(*pvmw.pte))
                        pte = pte_mkuffd_wp(pte);
 
-               if (unlikely(is_zone_device_page(new))) {
-                       if (is_device_private_page(new)) {
-                               entry = make_device_private_entry(new, pte_write(pte));
-                               pte = swp_entry_to_pte(entry);
-                               if (pte_swp_uffd_wp(*pvmw.pte))
-                                       pte = pte_swp_mkuffd_wp(pte);
-                       }
+               if (unlikely(is_device_private_page(new))) {
+                       entry = make_device_private_entry(new, pte_write(pte));
+                       pte = swp_entry_to_pte(entry);
+                       if (pte_swp_uffd_wp(*pvmw.pte))
+                               pte = pte_swp_mkuffd_wp(pte);
                }
 
 #ifdef CONFIG_HUGETLB_PAGE