1 files changed, 16 insertions, 4 deletions

diff --git a/mm/memory.c b/mm/memory.c
index d68421dd64ef..0f60baf6f69b 100644
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -1980,9 +1980,10 @@ static inline int handle_pte_fault(struct mm_struct *mm,
                 pte_t *pte, pmd_t *pmd, int write_access)
 {
         pte_t entry;
+        pte_t old_entry;
         spinlock_t *ptl;
 
-        entry = *pte;
+        old_entry = entry = *pte;
         if (!pte_present(entry)) {
                 if (pte_none(entry)) {
                         if (!vma->vm_ops || !vma->vm_ops->nopage)
@@ -2009,9 +2010,20 @@ static inline int handle_pte_fault(struct mm_struct *mm,
                 entry = pte_mkdirty(entry);
         }
         entry = pte_mkyoung(entry);
-        ptep_set_access_flags(vma, address, pte, entry, write_access);
-        update_mmu_cache(vma, address, entry);
-        lazy_mmu_prot_update(entry);
+        if (!pte_same(old_entry, entry)) {
+                ptep_set_access_flags(vma, address, pte, entry, write_access);
+                update_mmu_cache(vma, address, entry);
+                lazy_mmu_prot_update(entry);
+        } else {
+                /*
+                 * This is needed only for protection faults but the arch code
+                 * is not yet telling us if this is a protection fault or not.
+                 * This still avoids useless tlb flushes for .text page faults
+                 * with threads.
+                 */
+                if (write_access)
+                        flush_tlb_page(vma, address);
+        }
 unlock:
         pte_unmap_unlock(pte, ptl);
         return VM_FAULT_MINOR;