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[tip:x86/mm] mm/gup: Mark all pages PageReferenced in generic get_user_pages_fast()




Commit-ID:  e93480537fd7ecaf5ed1a662a979376f6fee50e3
Gitweb:     http://git.kernel.org/tip/e93480537fd7ecaf5ed1a662a979376f6fee50e3
Author:     Kirill A. Shutemov <kirill.shutemov@xxxxxxxxxxxxxxx>
AuthorDate: Thu, 16 Mar 2017 18:26:52 +0300
Committer:  Ingo Molnar <mingo@xxxxxxxxxx>
CommitDate: Sat, 18 Mar 2017 09:48:02 +0100

mm/gup: Mark all pages PageReferenced in generic get_user_pages_fast()

This is a preparation patch for the transition of x86 to the generic GUP_fast()
implementation.

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

See the following commit:

  8ee53820edfd ("thp: mmu_notifier_test_young")

Signed-off-by: Kirill A. Shutemov <kirill.shutemov@xxxxxxxxxxxxxxx>
Cc: Andrea Arcangeli <aarcange@xxxxxxxxxx>
Cc: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
Cc: Aneesh Kumar K . V <aneesh.kumar@xxxxxxxxxxxxxxxxxx>
Cc: Borislav Petkov <bp@xxxxxxxxx>
Cc: Catalin Marinas <catalin.marinas@xxxxxxx>
Cc: Dann Frazier <dann.frazier@xxxxxxxxxxxxx>
Cc: Dave Hansen <dave.hansen@xxxxxxxxx>
Cc: H. Peter Anvin <hpa@xxxxxxxxx>
Cc: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Cc: Rik van Riel <riel@xxxxxxxxxx>
Cc: Steve Capper <steve.capper@xxxxxxxxxx>
Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Cc: linux-arch@xxxxxxxxxxxxxxx
Cc: linux-mm@xxxxxxxxx
Link: http://lkml.kernel.org/r/20170316152655.37789-5-kirill.shutemov@xxxxxxxxxxxxxxx
Signed-off-by: Ingo Molnar <mingo@xxxxxxxxxx>
---
 mm/gup.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/mm/gup.c b/mm/gup.c
index e83db38..2b6cd357 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;
 }