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-rw-r--r--mm/ksm.c15
1 files changed, 13 insertions, 2 deletions
diff --git a/mm/ksm.c b/mm/ksm.c
index 6cb60f46cce5..be8f4576f842 100644
--- a/mm/ksm.c
+++ b/mm/ksm.c
@@ -1052,8 +1052,13 @@ static int write_protect_page(struct vm_area_struct *vma, struct page *page,
* So we clear the pte and flush the tlb before the check
* this assure us that no O_DIRECT can happen after the check
* or in the middle of the check.
+ *
+ * No need to notify as we are downgrading page table to read
+ * only not changing it to point to a new page.
+ *
+ * See Documentation/vm/mmu_notifier.txt
*/
- entry = ptep_clear_flush_notify(vma, pvmw.address, pvmw.pte);
+ entry = ptep_clear_flush(vma, pvmw.address, pvmw.pte);
/*
* Check that no O_DIRECT or similar I/O is in progress on the
* page
@@ -1136,7 +1141,13 @@ static int replace_page(struct vm_area_struct *vma, struct page *page,
}
flush_cache_page(vma, addr, pte_pfn(*ptep));
- ptep_clear_flush_notify(vma, addr, ptep);
+ /*
+ * No need to notify as we are replacing a read only page with another
+ * read only page with the same content.
+ *
+ * See Documentation/vm/mmu_notifier.txt
+ */
+ ptep_clear_flush(vma, addr, ptep);
set_pte_at_notify(mm, addr, ptep, newpte);
page_remove_rmap(page, false);