[PATCH] mm: do not use mm->nr_pmds on !MMU configurations

From: Kirill A. Shutemov
Date: Fri Jan 30 2015 - 19:36:36 EST


mm->nr_pmds doesn't make sense on !MMU configurations

Signed-off-by: Kirill A. Shutemov <kirill.shutemov@xxxxxxxxxxxxxxx>
---
This patch should probably go before the series.
---
include/linux/mm.h | 9 ++++++++-
kernel/fork.c | 4 +---
2 files changed, 9 insertions(+), 4 deletions(-)

diff --git a/include/linux/mm.h b/include/linux/mm.h
index d782617c11de..a09837f3f4b7 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -1454,13 +1454,15 @@ static inline int __pud_alloc(struct mm_struct *mm, pgd_t *pgd,
int __pud_alloc(struct mm_struct *mm, pgd_t *pgd, unsigned long address);
#endif

-#ifdef __PAGETABLE_PMD_FOLDED
+#if defined(__PAGETABLE_PMD_FOLDED) || !defined(CONFIG_MMU)
static inline int __pmd_alloc(struct mm_struct *mm, pud_t *pud,
unsigned long address)
{
return 0;
}

+static inline void mm_nr_pmds_init(struct mm_struct *mm) {}
+
static inline unsigned long mm_nr_pmds(struct mm_struct *mm)
{
return 0;
@@ -1472,6 +1474,11 @@ static inline void mm_dec_nr_pmds(struct mm_struct *mm) {}
#else
int __pmd_alloc(struct mm_struct *mm, pud_t *pud, unsigned long address);

+static inline void mm_nr_pmds_init(struct mm_struct *mm)
+{
+ atomic_long_set(&mm->nr_pmds, 0);
+}
+
static inline unsigned long mm_nr_pmds(struct mm_struct *mm)
{
return atomic_long_read(&mm->nr_pmds);
diff --git a/kernel/fork.c b/kernel/fork.c
index 76d6f292274c..56b82deb6457 100644
--- a/kernel/fork.c
+++ b/kernel/fork.c
@@ -555,9 +555,7 @@ static struct mm_struct *mm_init(struct mm_struct *mm, struct task_struct *p)
INIT_LIST_HEAD(&mm->mmlist);
mm->core_state = NULL;
atomic_long_set(&mm->nr_ptes, 0);
-#ifndef __PAGETABLE_PMD_FOLDED
- atomic_long_set(&mm->nr_pmds, 0);
-#endif
+ mm_nr_pmds_init(mm);
mm->map_count = 0;
mm->locked_vm = 0;
mm->pinned_vm = 0;
--
2.1.4

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