From e93480537fd7ecaf5ed1a662a979376f6fee50e3 Mon Sep 17 00:00:00 2001
From: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Date: Thu, 16 Mar 2017 18:26:52 +0300
Subject: [PATCH] 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@linux.intel.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Aneesh Kumar K . V <aneesh.kumar@linux.vnet.ibm.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Dann Frazier <dann.frazier@canonical.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rik van Riel <riel@redhat.com>
Cc: Steve Capper <steve.capper@linaro.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-arch@vger.kernel.org
Cc: linux-mm@kvack.org
Link: http://lkml.kernel.org/r/20170316152655.37789-5-kirill.shutemov@linux.intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
---
mm/gup.c | 5 +++++
1 file changed, 5 insertions(+)
diff --git a/mm/gup.c b/mm/gup.c
index e83db38deb17..2b6cd3573457 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;
}