5 files changed, 8 insertions, 20 deletions

diff --git a/include/linux/ksm.h b/include/linux/ksm.h
index 2d64ff30c0de..0e26de6adb51 100644
--- a/include/linux/ksm.h
+++ b/include/linux/ksm.h
@@ -18,8 +18,7 @@ struct mmu_gather;
 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,
-                struct mmu_gather **tlbp, unsigned long end);
+void __ksm_exit(struct mm_struct *mm);
 
 static inline int ksm_fork(struct mm_struct *mm, struct mm_struct *oldmm)
 {
@@ -41,11 +40,10 @@ static inline bool ksm_test_exit(struct mm_struct *mm)
         return atomic_read(&mm->mm_users) == 0;
 }
 
-static inline void ksm_exit(struct mm_struct *mm,
-                            struct mmu_gather **tlbp, unsigned long end)
+static inline void ksm_exit(struct mm_struct *mm)
 {
         if (test_bit(MMF_VM_MERGEABLE, &mm->flags))
-                __ksm_exit(mm, tlbp, end);
+                __ksm_exit(mm);
 }
 
 /*
@@ -86,8 +84,7 @@ static inline bool ksm_test_exit(struct mm_struct *mm)
         return 0;
 }
 
-static inline void ksm_exit(struct mm_struct *mm,
-                            struct mmu_gather **tlbp, unsigned long end)
+static inline void ksm_exit(struct mm_struct *mm)
 {
 }
 
diff --git a/kernel/fork.c b/kernel/fork.c
index 42f20f565b16..73a442b7be6d 100644
--- a/kernel/fork.c
+++ b/kernel/fork.c
@@ -501,6 +501,7 @@ void mmput(struct mm_struct *mm)
 
         if (atomic_dec_and_test(&mm->mm_users)) {
                 exit_aio(mm);
+                ksm_exit(mm);
                 exit_mmap(mm);
                 set_mm_exe_file(mm, NULL);
                 if (!list_empty(&mm->mmlist)) {
diff --git a/mm/ksm.c b/mm/ksm.c
index 722e3f2a8dc5..92034eb47eba 100644
--- a/mm/ksm.c
+++ b/mm/ksm.c
@@ -1416,8 +1416,7 @@ int __ksm_enter(struct mm_struct *mm)
         return 0;
 }
 
-void __ksm_exit(struct mm_struct *mm,
-                struct mmu_gather **tlbp, unsigned long end)
+void __ksm_exit(struct mm_struct *mm)
 {
         struct mm_slot *mm_slot;
         int easy_to_free = 0;
@@ -1450,10 +1449,8 @@ void __ksm_exit(struct mm_struct *mm,
                 clear_bit(MMF_VM_MERGEABLE, &mm->flags);
                 mmdrop(mm);
         } else if (mm_slot) {
-                tlb_finish_mmu(*tlbp, 0, end);
                 down_write(&mm->mmap_sem);
                 up_write(&mm->mmap_sem);
-                *tlbp = tlb_gather_mmu(mm, 1);
         }
 }
 
diff --git a/mm/memory.c b/mm/memory.c
index f47ffe971012..05feaa11d87c 100644
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -2648,7 +2648,7 @@ static int do_anonymous_page(struct mm_struct *mm, struct vm_area_struct *vma,
         entry = maybe_mkwrite(pte_mkdirty(entry), vma);
 
         page_table = pte_offset_map_lock(mm, pmd, address, &ptl);
-        if (!pte_none(*page_table) || ksm_test_exit(mm))
+        if (!pte_none(*page_table))
                 goto release;
 
         inc_mm_counter(mm, anon_rss);
@@ -2792,7 +2792,7 @@ static int __do_fault(struct mm_struct *mm, struct vm_area_struct *vma,
          * handle that later.
          */
         /* Only go through if we didn't race with anybody else... */
-        if (likely(pte_same(*page_table, orig_pte) && !ksm_test_exit(mm))) {
+        if (likely(pte_same(*page_table, orig_pte))) {
                 flush_icache_page(vma, page);
                 entry = mk_pte(page, vma->vm_page_prot);
                 if (flags & FAULT_FLAG_WRITE)
diff --git a/mm/mmap.c b/mm/mmap.c
index e02f1aa66a1a..ffd6c6c9bcf4 100644
--- a/mm/mmap.c
+++ b/mm/mmap.c
@@ -2113,13 +2113,6 @@ void exit_mmap(struct mm_struct *mm)
         end = unmap_vmas(&tlb, vma, 0, -1, &nr_accounted, NULL);
         vm_unacct_memory(nr_accounted);
 
-        /*
-         * For KSM to handle OOM without deadlock when it's breaking COW in a
-         * likely victim of the OOM killer, we must serialize with ksm_exit()
-         * after freeing mm's pages but before freeing its page tables.
-         */
-        ksm_exit(mm, &tlb, end);
-
         free_pgtables(tlb, vma, FIRST_USER_ADDRESS, 0);
         tlb_finish_mmu(tlb, 0, end);