[PATCH 1/3] Revert "thp: make MADV_HUGEPAGE check for mm->def_flags"

From: Alex Thorlton
Date: Fri Jan 31 2014 - 13:24:31 EST


This reverts commit 8e72033f2a489b6c98c4e3c7cc281b1afd6cb85cm, and adds
in code to fix up any issues caused by the revert.

The revert is necessary because hugepage_madvise would return -EINVAL
when VM_NOHUGEPAGE is set, which will break subsequent chunks of this
patch set.

Signed-off-by: Alex Thorlton <athorlton@xxxxxxx>
Suggested-by: Oleg Nesterov <oleg@xxxxxxxxxx>
Cc: Oleg Nesterov <oleg@xxxxxxxxxx>
Cc: Gerald Schaefer <gerald.schaefer@xxxxxxxxxx>
Cc: Martin Schwidefsky <schwidefsky@xxxxxxxxxx>
Cc: Heiko Carstens <heiko.carstens@xxxxxxxxxx>
Cc: Christian Borntraeger <borntraeger@xxxxxxxxxx>
Cc: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
Cc: Paolo Bonzini <pbonzini@xxxxxxxxxx>
Cc: "Kirill A. Shutemov" <kirill.shutemov@xxxxxxxxxxxxxxx>
Cc: Mel Gorman <mgorman@xxxxxxx>
Cc: Rik van Riel <riel@xxxxxxxxxx>
Cc: Ingo Molnar <mingo@xxxxxxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Cc: Sasha Levin <sasha.levin@xxxxxxxxxx>
Cc: linux390@xxxxxxxxxx
Cc: linux-s390@xxxxxxxxxxxxxxx
Cc: linux-kernel@xxxxxxxxxxxxxxx
Cc: linux-mm@xxxxxxxxx

---
arch/s390/mm/pgtable.c | 3 +++
mm/huge_memory.c | 4 ----
2 files changed, 3 insertions(+), 4 deletions(-)

diff --git a/arch/s390/mm/pgtable.c b/arch/s390/mm/pgtable.c
index 3584ed9..a87cdb4 100644
--- a/arch/s390/mm/pgtable.c
+++ b/arch/s390/mm/pgtable.c
@@ -504,6 +504,9 @@ static int gmap_connect_pgtable(unsigned long address, unsigned long segment,
if (!pmd_present(*pmd) &&
__pte_alloc(mm, vma, pmd, vmaddr))
return -ENOMEM;
+ /* large pmds cannot yet be handled */
+ if (pmd_large(*pmd))
+ return -EFAULT;
/* pmd now points to a valid segment table entry. */
rmap = kmalloc(sizeof(*rmap), GFP_KERNEL|__GFP_REPEAT);
if (!rmap)
diff --git a/mm/huge_memory.c b/mm/huge_memory.c
index 82166bf..a4310a5 100644
--- a/mm/huge_memory.c
+++ b/mm/huge_memory.c
@@ -1968,8 +1968,6 @@ out:
int hugepage_madvise(struct vm_area_struct *vma,
unsigned long *vm_flags, int advice)
{
- struct mm_struct *mm = vma->vm_mm;
-
switch (advice) {
case MADV_HUGEPAGE:
/*
@@ -1977,8 +1975,6 @@ int hugepage_madvise(struct vm_area_struct *vma,
*/
if (*vm_flags & (VM_HUGEPAGE | VM_NO_THP))
return -EINVAL;
- if (mm->def_flags & VM_NOHUGEPAGE)
- return -EINVAL;
*vm_flags &= ~VM_NOHUGEPAGE;
*vm_flags |= VM_HUGEPAGE;
/*
--
1.7.12.4

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