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@devkernel.io --- 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 56808e3bfd19..afc0980592af 100644 --- a/mm/ksm.c +++ b/mm/ksm.c @@ -2595,8 +2595,9 @@ 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; } @@ -2622,7 +2623,7 @@ 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; @@ -2655,7 +2656,7 @@ 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)