This change adds the flag parameter to __ksm_enter. This allows to
distinguish if ksm was called by prctl or madvise.
Signed-off-by: Stefan Roesch <shr@xxxxxxxxxxxx>
---
include/linux/ksm.h | 6 ++++--
mm/ksm.c | 9 +++++----
2 files changed, 9 insertions(+), 6 deletions(-)
diff --git a/include/linux/ksm.h b/include/linux/ksm.h
index 7e232ba59b86..50e6b56092f3 100644
--- a/include/linux/ksm.h
+++ b/include/linux/ksm.h
@@ -18,13 +18,15 @@
#ifdef CONFIG_KSM
int ksm_madvise(struct vm_area_struct *vma, unsigned long start,
unsigned long end, int advice, unsigned long *vm_flags);
-int __ksm_enter(struct mm_struct *mm);
void __ksm_exit(struct mm_struct *mm);
+int __ksm_enter(struct mm_struct *mm, int flag);
static inline int ksm_fork(struct mm_struct *mm, struct mm_struct *oldmm)
{
+ if (test_bit(MMF_VM_MERGE_ANY, &oldmm->flags))
+ return __ksm_enter(mm, MMF_VM_MERGE_ANY);
if (test_bit(MMF_VM_MERGEABLE, &oldmm->flags))
- return __ksm_enter(mm);
+ return __ksm_enter(mm, MMF_VM_MERGEABLE);
return 0;
}
diff --git a/mm/ksm.c b/mm/ksm.c
index dd02780c387f..d84a244fe224 100644
--- a/mm/ksm.c
+++ b/mm/ksm.c
@@ -2493,8 +2493,9 @@ int ksm_madvise(struct vm_area_struct *vma, unsigned long start,
return 0;
#endif
- if (!test_bit(MMF_VM_MERGEABLE, &mm->flags)) {
- err = __ksm_enter(mm);
+ if (!test_bit(MMF_VM_MERGEABLE, &mm->flags) &&
+ !test_bit(MMF_VM_MERGE_ANY, &mm->flags)) {
+ err = __ksm_enter(mm, MMF_VM_MERGEABLE);
if (err)
return err;
}
@@ -2520,7 +2521,7 @@ int ksm_madvise(struct vm_area_struct *vma, unsigned long start,
}
EXPORT_SYMBOL_GPL(ksm_madvise);
-int __ksm_enter(struct mm_struct *mm)
+int __ksm_enter(struct mm_struct *mm, int flag)
{
struct ksm_mm_slot *mm_slot;
struct mm_slot *slot;
@@ -2553,7 +2554,7 @@ int __ksm_enter(struct mm_struct *mm)
list_add_tail(&slot->mm_node, &ksm_scan.mm_slot->slot.mm_node);
spin_unlock(&ksm_mmlist_lock);
- set_bit(MMF_VM_MERGEABLE, &mm->flags);
+ set_bit(flag, &mm->flags);
mmgrab(mm);
if (needs_wakeup)
--
2.30.2
