This adds the ability to disable ksm for a process if ksm has been enabled for the process.
Signed-off-by: Stefan Roesch shr@devkernel.io --- mm/ksm.c | 25 ++++++++++++++++++++++++- 1 file changed, 24 insertions(+), 1 deletion(-)
diff --git a/mm/ksm.c b/mm/ksm.c index 967eda719fab..5fa6b46dfa3b 100644 --- a/mm/ksm.c +++ b/mm/ksm.c @@ -2588,6 +2588,27 @@ int __ksm_enter(struct mm_struct *mm, int flag) return 0; }
+static void unmerge_vmas(struct mm_struct *mm) +{ + struct vm_area_struct *vma; + struct vma_iterator vmi; + + vma_iter_init(&vmi, mm, 0); + + mmap_read_lock(mm); + for_each_vma(vmi, vma) { + if (vma->vm_flags & VM_MERGEABLE) { + unsigned long flags = vma->vm_flags; + + if (ksm_madvise(vma, vma->vm_start, vma->vm_end, MADV_UNMERGEABLE, &flags)) + continue; + + vma->vm_flags = flags; + } + } + mmap_read_unlock(mm); +} + void __ksm_exit(struct mm_struct *mm, int flag) { struct ksm_mm_slot *mm_slot; @@ -2595,8 +2616,10 @@ void __ksm_exit(struct mm_struct *mm, int flag) int easy_to_free = 0;
if (!(current->flags & PF_EXITING) && flag == MMF_VM_MERGE_ANY && - test_bit(MMF_VM_MERGE_ANY, &mm->flags)) + test_bit(MMF_VM_MERGE_ANY, &mm->flags)) { clear_bit(MMF_VM_MERGE_ANY, &mm->flags); + unmerge_vmas(mm); + }
/* * This process is exiting: if it's straightforward (as is the