[ 3.5.y.z extended stable ] Patch "mm/hugetlb: set PTE as huge in hugetlb_change_protection and" has been added to staging queue

Herton Ronaldo Krzesinski herton.krzesinski at canonical.com
Tue Feb 12 21:19:28 UTC 2013

This is a note to let you know that I have just added a patch titled

    mm/hugetlb: set PTE as huge in hugetlb_change_protection and

to the linux-3.5.y-queue branch of the 3.5.y.z extended stable tree 
which can be found at:


If you, or anyone else, feels it should not be added to this tree, please 
reply to this email.

For more information about the 3.5.y.z tree, see



>From 4831ae249d849a5bfe92c837bbf204bfe4b9670e Mon Sep 17 00:00:00 2001
From: Tony Lu <zlu at tilera.com>
Date: Mon, 4 Feb 2013 14:28:46 -0800
Subject: [PATCH] mm/hugetlb: set PTE as huge in hugetlb_change_protection and

commit be7517d6ab9722f0abad6ba5ffd39cfced95549c upstream.

When setting a huge PTE, besides calling pte_mkhuge(), we also need to
call arch_make_huge_pte(), which we indeed do in make_huge_pte(), but we
forget to do in hugetlb_change_protection() and remove_migration_pte().

Signed-off-by: Zhigang Lu <zlu at tilera.com>
Signed-off-by: Chris Metcalf <cmetcalf at tilera.com>
Reviewed-by: Michal Hocko <mhocko at suse.cz>
Acked-by: Hillf Danton <dhillf at gmail.com>
Signed-off-by: Andrew Morton <akpm at linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds at linux-foundation.org>
[ herton: adjust context ]
Signed-off-by: Herton Ronaldo Krzesinski <herton.krzesinski at canonical.com>
 mm/hugetlb.c |    1 +
 mm/migrate.c |    4 +++-
 2 files changed, 4 insertions(+), 1 deletion(-)

diff --git a/mm/hugetlb.c b/mm/hugetlb.c
index 9c34eb5..33d8b38 100644
--- a/mm/hugetlb.c
+++ b/mm/hugetlb.c
@@ -2972,6 +2972,7 @@ void hugetlb_change_protection(struct vm_area_struct *vma,
 		if (!huge_pte_none(huge_ptep_get(ptep))) {
 			pte = huge_ptep_get_and_clear(mm, address, ptep);
 			pte = pte_mkhuge(pte_modify(pte, newprot));
+			pte = arch_make_huge_pte(pte, vma, NULL, 0);
 			set_huge_pte_at(mm, address, ptep, pte);
diff --git a/mm/migrate.c b/mm/migrate.c
index be26d5c..2e03986 100644
--- a/mm/migrate.c
+++ b/mm/migrate.c
@@ -142,8 +142,10 @@ static int remove_migration_pte(struct page *new, struct vm_area_struct *vma,
 	if (is_write_migration_entry(entry))
 		pte = pte_mkwrite(pte);
-	if (PageHuge(new))
+	if (PageHuge(new)) {
 		pte = pte_mkhuge(pte);
+		pte = arch_make_huge_pte(pte, vma, new, 0);
+	}
 	flush_cache_page(vma, addr, pte_pfn(pte));
 	set_pte_at(mm, addr, ptep, pte);

More information about the kernel-team mailing list