Merge branch 'akpm' (incoming from Andrew)

Merge patches from Andrew Morton:
 "23 fixes and a MAINTAINERS update"

* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (24 commits)
  mm/hugetlb: check for pte NULL pointer in __page_check_address()
  fix build with make 3.80
  mm/mempolicy: fix !vma in new_vma_page()
  MAINTAINERS: add Davidlohr as GPT maintainer
  mm/memory-failure.c: recheck PageHuge() after hugetlb page migrate successfully
  mm/compaction: respect ignore_skip_hint in update_pageblock_skip
  mm/mempolicy: correct putback method for isolate pages if failed
  mm: add missing dependency in Kconfig
  sh: always link in helper functions extracted from libgcc
  mm: page_alloc: exclude unreclaimable allocations from zone fairness policy
  mm: numa: defer TLB flush for THP migration as long as possible
  mm: numa: guarantee that tlb_flush_pending updates are visible before page table updates
  mm: fix TLB flush race between migration, and change_protection_range
  mm: numa: avoid unnecessary disruption of NUMA hinting during migration
  mm: numa: clear numa hinting information on mprotect
  sched: numa: skip inaccessible VMAs
  mm: numa: avoid unnecessary work on the failure path
  mm: numa: ensure anon_vma is locked to prevent parallel THP splits
  mm: numa: do not clear PTE for pte_numa update
  mm: numa: do not clear PMD during PTE update scan
  ...

4 files changed, 60 insertions, 1 deletions

diff --git a/include/asm-generic/pgtable.h b/include/asm-generic/pgtable.h
index f330d28e4d0e..b12079afbd5f 100644
--- a/include/asm-generic/pgtable.h
+++ b/include/asm-generic/pgtable.h
@@ -217,7 +217,7 @@ static inline int pmd_same(pmd_t pmd_a, pmd_t pmd_b)
 #endif
 
 #ifndef pte_accessible
-# define pte_accessible(pte)            ((void)(pte),1)
+# define pte_accessible(mm, pte)        ((void)(pte), 1)
 #endif
 
 #ifndef flush_tlb_fix_spurious_fault
diff --git a/include/linux/migrate.h b/include/linux/migrate.h
index f5096b58b20d..b7717d74da7f 100644
--- a/include/linux/migrate.h
+++ b/include/linux/migrate.h
@@ -90,10 +90,19 @@ static inline int migrate_huge_page_move_mapping(struct address_space *mapping,
 #endif /* CONFIG_MIGRATION */
 
 #ifdef CONFIG_NUMA_BALANCING
+extern bool pmd_trans_migrating(pmd_t pmd);
+extern void wait_migrate_huge_page(struct anon_vma *anon_vma, pmd_t *pmd);
 extern int migrate_misplaced_page(struct page *page,
                                   struct vm_area_struct *vma, int node);
 extern bool migrate_ratelimited(int node);
 #else
+static inline bool pmd_trans_migrating(pmd_t pmd)
+{
+        return false;
+}
+static inline void wait_migrate_huge_page(struct anon_vma *anon_vma, pmd_t *pmd)
+{
+}
 static inline int migrate_misplaced_page(struct page *page,
                                          struct vm_area_struct *vma, int node)
 {
diff --git a/include/linux/mm_types.h b/include/linux/mm_types.h
index bd299418a934..ad0616f2fe2c 100644
--- a/include/linux/mm_types.h
+++ b/include/linux/mm_types.h
@@ -443,6 +443,14 @@ struct mm_struct {
         /* numa_scan_seq prevents two threads setting pte_numa */
         int numa_scan_seq;
 #endif
+#if defined(CONFIG_NUMA_BALANCING) || defined(CONFIG_COMPACTION)
+        /*
+         * An operation with batched TLB flushing is going on. Anything that
+         * can move process memory needs to flush the TLB when moving a
+         * PROT_NONE or PROT_NUMA mapped page.
+         */
+        bool tlb_flush_pending;
+#endif
         struct uprobes_state uprobes_state;
 };
 
@@ -459,4 +467,45 @@ static inline cpumask_t *mm_cpumask(struct mm_struct *mm)
         return mm->cpu_vm_mask_var;
 }
 
+#if defined(CONFIG_NUMA_BALANCING) || defined(CONFIG_COMPACTION)
+/*
+ * Memory barriers to keep this state in sync are graciously provided by
+ * the page table locks, outside of which no page table modifications happen.
+ * The barriers below prevent the compiler from re-ordering the instructions
+ * around the memory barriers that are already present in the code.
+ */
+static inline bool mm_tlb_flush_pending(struct mm_struct *mm)
+{
+        barrier();
+        return mm->tlb_flush_pending;
+}
+static inline void set_tlb_flush_pending(struct mm_struct *mm)
+{
+        mm->tlb_flush_pending = true;
+
+        /*
+         * Guarantee that the tlb_flush_pending store does not leak into the
+         * critical section updating the page tables
+         */
+        smp_mb__before_spinlock();
+}
+/* Clearing is done after a TLB flush, which also provides a barrier. */
+static inline void clear_tlb_flush_pending(struct mm_struct *mm)
+{
+        barrier();
+        mm->tlb_flush_pending = false;
+}
+#else
+static inline bool mm_tlb_flush_pending(struct mm_struct *mm)
+{
+        return false;
+}
+static inline void set_tlb_flush_pending(struct mm_struct *mm)
+{
+}
+static inline void clear_tlb_flush_pending(struct mm_struct *mm)
+{
+}
+#endif
+
 #endif /* _LINUX_MM_TYPES_H */
diff --git a/include/linux/reboot.h b/include/linux/reboot.h
index 8e00f9f6f963..9e7db9e73cc1 100644
--- a/include/linux/reboot.h
+++ b/include/linux/reboot.h
@@ -43,6 +43,7 @@ extern int unregister_reboot_notifier(struct notifier_block *);
  * Architecture-specific implementations of sys_reboot commands.
  */
 
+extern void migrate_to_reboot_cpu(void);
 extern void machine_restart(char *cmd);
 extern void machine_halt(void);
 extern void machine_power_off(void);