David Hildenbrand david@redhat.com writes:

...

+static void __ksm_add_vma(struct vm_area_struct *vma) +{

• unsigned long vm_flags = vma->vm_flags;
• if (vm_flags & VM_MERGEABLE)

• return;
  

• if (vma_ksm_compatible(vma)) {

• vm_flags |= VM_MERGEABLE;
  

• vm_flags_reset(vma, vm_flags);
  

• }

+}

We can do the following simplification on top:

diff --git a/mm/ksm.c b/mm/ksm.c index 905c8edce5cf..26e7f585d65d 100644 --- a/mm/ksm.c +++ b/mm/ksm.c @@ -2511,15 +2511,11 @@ static int ksm_scan_thread(void *nothing)

static void __ksm_add_vma(struct vm_area_struct *vma) {

• unsigned long vm_flags = vma->vm_flags;
• if (vm_flags & VM_MERGEABLE)

• if (vma->vm_flags & VM_MERGEABLE) return;

• if (vma_ksm_compatible(vma)) {

• vm_flags |= VM_MERGEABLE;
  

• vm_flags_reset(vma, vm_flags);
  

• }

• if (vma_ksm_compatible(vma))

• vm_flags_set(vma, VM_MERGEABLE);
  

}

/**

2.39.2

The next version has the above change.

I have some patches based on your patch set (handling/testing unmerging whens setting PR_SET_MEMORY_MERGE=0. Will send out once you changes are queued.