linux-kernel - [PATCH 1/2] mm/migrate: remove unnecessary is_zone_device

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Date:   Mon, 31 Aug 2020 14:22:21 -0700
From:   Ralph Campbell <rcampbell@...dia.com>
To:     <linux-mm@...ck.org>, <linux-kernel@...r.kernel.org>
CC:     Jerome Glisse <jglisse@...hat.com>,
        Alistair Popple <apopple@...dia.com>,
        Christoph Hellwig <hch@....de>,
        Jason Gunthorpe <jgg@...dia.com>,
        Bharata B Rao <bharata@...ux.ibm.com>,
        Andrew Morton <akpm@...ux-foundation.org>,
        Ralph Campbell <rcampbell@...dia.com>
Subject: [PATCH 1/2] mm/migrate: remove unnecessary is_zone_device_page() check

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@...dia.com>
---
 mm/migrate.c | 12 +++++-------
 1 file changed, 5 insertions(+), 7 deletions(-)

diff --git a/mm/migrate.c b/mm/migrate.c
index 659d3d8a3e1f..fe339a847328 100644
--- 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
-- 
2.20.1