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Subject[PATCH 4/7] mm/gup: Make pages referenced during generic get_user_pages_fast()
Date
This is preparation patch for transition of x86 to generic GUP_fast()
implementation.

Unlike generic GUP_fast(), x86 version makes all pages it touches
referenced. It seems required for GRU and EPT.

See commit 8ee53820edfd ("thp: mmu_notifier_test_young").

Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
---
mm/gup.c | 5 +++++
1 file changed, 5 insertions(+)

diff --git a/mm/gup.c b/mm/gup.c
index ed2259dc4606..f0cfe225c08f 100644
--- a/mm/gup.c
+++ b/mm/gup.c
@@ -1238,6 +1238,8 @@ static int gup_pte_range(pmd_t pmd, unsigned long addr, unsigned long end,
}

VM_BUG_ON_PAGE(compound_head(page) != head, page);
+
+ SetPageReferenced(page);
pages[*nr] = page;
(*nr)++;

@@ -1299,6 +1301,7 @@ static int gup_huge_pmd(pmd_t orig, pmd_t *pmdp, unsigned long addr,
return 0;
}

+ SetPageReferenced(head);
return 1;
}

@@ -1334,6 +1337,7 @@ static int gup_huge_pud(pud_t orig, pud_t *pudp, unsigned long addr,
return 0;
}

+ SetPageReferenced(head);
return 1;
}

@@ -1370,6 +1374,7 @@ static int gup_huge_pgd(pgd_t orig, pgd_t *pgdp, unsigned long addr,
return 0;
}

+ SetPageReferenced(head);
return 1;
}

--
2.11.0
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