Merge branch 'akpm' (patches from Andrew)

Merge fixes from Andrew Morton:
 "6 fixes"

* emailed patches from Andrew Morton <akpm@linux-foundation.org>:
  mm: proc: smaps_rollup: fix pss_locked calculation
  Rename include/{uapi => }/asm-generic/shmparam.h really
  Revert "mm: use early_pfn_to_nid in page_ext_init"
  mm/gup: fix gup_pmd_range() for dax
  Revert "mm: slowly shrink slabs with a relatively small number of objects"
  Revert "mm: don't reclaim inodes with many attached pages"

7 files changed, 21 insertions, 28 deletions

diff --git a/fs/inode.c b/fs/inode.c
index 0cd47fe0dbe5..73432e64f874 100644
--- a/fs/inode.c
+++ b/fs/inode.c
@@ -730,11 +730,8 @@ static enum lru_status inode_lru_isolate(struct list_head *item,
 		return LRU_REMOVED;
 	}
 
-	/*
-	 * Recently referenced inodes and inodes with many attached pages
-	 * get one more pass.
-	 */
-	if (inode->i_state & I_REFERENCED || inode->i_data.nrpages > 1) {
+	/* recently referenced inodes get one more pass */
+	if (inode->i_state & I_REFERENCED) {
 		inode->i_state &= ~I_REFERENCED;
 		spin_unlock(&inode->i_lock);
 		return LRU_ROTATE;
diff --git a/fs/proc/task_mmu.c b/fs/proc/task_mmu.c
index f0ec9edab2f3..85b0ef890b28 100644
--- a/fs/proc/task_mmu.c
+++ b/fs/proc/task_mmu.c
@@ -423,7 +423,7 @@ struct mem_size_stats {
 };
 
 static void smaps_account(struct mem_size_stats *mss, struct page *page,
-		bool compound, bool young, bool dirty)
+		bool compound, bool young, bool dirty, bool locked)
 {
 	int i, nr = compound ? 1 << compound_order(page) : 1;
 	unsigned long size = nr * PAGE_SIZE;
@@ -450,24 +450,31 @@ static void smaps_account(struct mem_size_stats *mss, struct page *page,
 		else
 			mss->private_clean += size;
 		mss->pss += (u64)size << PSS_SHIFT;
+		if (locked)
+			mss->pss_locked += (u64)size << PSS_SHIFT;
 		return;
 	}
 
 	for (i = 0; i < nr; i++, page++) {
 		int mapcount = page_mapcount(page);
+		unsigned long pss = (PAGE_SIZE << PSS_SHIFT);
 
 		if (mapcount >= 2) {
 			if (dirty || PageDirty(page))
 				mss->shared_dirty += PAGE_SIZE;
 			else
 				mss->shared_clean += PAGE_SIZE;
-			mss->pss += (PAGE_SIZE << PSS_SHIFT) / mapcount;
+			mss->pss += pss / mapcount;
+			if (locked)
+				mss->pss_locked += pss / mapcount;
 		} else {
 			if (dirty || PageDirty(page))
 				mss->private_dirty += PAGE_SIZE;
 			else
 				mss->private_clean += PAGE_SIZE;
-			mss->pss += PAGE_SIZE << PSS_SHIFT;
+			mss->pss += pss;
+			if (locked)
+				mss->pss_locked += pss;
 		}
 	}
 }
@@ -490,6 +497,7 @@ static void smaps_pte_entry(pte_t *pte, unsigned long addr,
 {
 	struct mem_size_stats *mss = walk->private;
 	struct vm_area_struct *vma = walk->vma;
+	bool locked = !!(vma->vm_flags & VM_LOCKED);
 	struct page *page = NULL;
 
 	if (pte_present(*pte)) {
@@ -532,7 +540,7 @@ static void smaps_pte_entry(pte_t *pte, unsigned long addr,
 	if (!page)
 		return;
 
-	smaps_account(mss, page, false, pte_young(*pte), pte_dirty(*pte));
+	smaps_account(mss, page, false, pte_young(*pte), pte_dirty(*pte), locked);
 }
 
 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
@@ -541,6 +549,7 @@ static void smaps_pmd_entry(pmd_t *pmd, unsigned long addr,
 {
 	struct mem_size_stats *mss = walk->private;
 	struct vm_area_struct *vma = walk->vma;
+	bool locked = !!(vma->vm_flags & VM_LOCKED);
 	struct page *page;
 
 	/* FOLL_DUMP will return -EFAULT on huge zero page */
@@ -555,7 +564,7 @@ static void smaps_pmd_entry(pmd_t *pmd, unsigned long addr,
 		/* pass */;
 	else
 		VM_BUG_ON_PAGE(1, page);
-	smaps_account(mss, page, true, pmd_young(*pmd), pmd_dirty(*pmd));
+	smaps_account(mss, page, true, pmd_young(*pmd), pmd_dirty(*pmd), locked);
 }
 #else
 static void smaps_pmd_entry(pmd_t *pmd, unsigned long addr,
@@ -737,11 +746,8 @@ static void smap_gather_stats(struct vm_area_struct *vma,
 		}
 	}
 #endif
-
 	/* mmap_sem is held in m_start */
 	walk_page_vma(vma, &smaps_walk);
-	if (vma->vm_flags & VM_LOCKED)
-		mss->pss_locked += mss->pss;
 }
 
 #define SEQ_PUT_DEC(str, val) \
diff --git a/include/uapi/asm-generic/shmparam.h b/include/asm-generic/shmparam.h
index 8b78c0ba08b1..8b78c0ba08b1 100644
--- a/include/uapi/asm-generic/shmparam.h
+++ b/include/asm-generic/shmparam.h
diff --git a/init/main.c b/init/main.c
index e2e80ca3165a..c86a1c8f19f4 100644
--- a/init/main.c
+++ b/init/main.c
@@ -695,7 +695,6 @@ asmlinkage __visible void __init start_kernel(void)
 		initrd_start = 0;
 	}
 #endif
-	page_ext_init();
 	kmemleak_init();
 	setup_per_cpu_pageset();
 	numa_policy_init();
@@ -1131,6 +1130,8 @@ static noinline void __init kernel_init_freeable(void)
 	sched_init_smp();
 
 	page_alloc_init_late();
+	/* Initialize page ext after all struct pages are initialized. */
+	page_ext_init();
 
 	do_basic_setup();
 
diff --git a/mm/gup.c b/mm/gup.c
index 05acd7e2eb22..75029649baca 100644
--- a/mm/gup.c
+++ b/mm/gup.c
@@ -1674,7 +1674,8 @@ static int gup_pmd_range(pud_t pud, unsigned long addr, unsigned long end,
 		if (!pmd_present(pmd))
 			return 0;
 
-		if (unlikely(pmd_trans_huge(pmd) || pmd_huge(pmd))) {
+		if (unlikely(pmd_trans_huge(pmd) || pmd_huge(pmd) ||
+			     pmd_devmap(pmd))) {
 			/*
 			 * NUMA hinting faults need to be handled in the GUP
 			 * slowpath for accounting purposes and so that they
diff --git a/mm/page_ext.c b/mm/page_ext.c
index ae44f7adbe07..8c78b8d45117 100644
--- a/mm/page_ext.c
+++ b/mm/page_ext.c
@@ -398,10 +398,8 @@ void __init page_ext_init(void)
 			 * We know some arch can have a nodes layout such as
 			 * -------------pfn-------------->
 			 * N0 | N1 | N2 | N0 | N1 | N2|....
-			 *
-			 * Take into account DEFERRED_STRUCT_PAGE_INIT.
 			 */
-			if (early_pfn_to_nid(pfn) != nid)
+			if (pfn_to_nid(pfn) != nid)
 				continue;
 			if (init_section_page_ext(pfn, nid))
 				goto oom;
diff --git a/mm/vmscan.c b/mm/vmscan.c
index a714c4f800e9..e979705bbf32 100644
--- a/mm/vmscan.c
+++ b/mm/vmscan.c
@@ -491,16 +491,6 @@ static unsigned long do_shrink_slab(struct shrink_control *shrinkctl,
 		delta = freeable / 2;
 	}
 
-	/*
-	 * Make sure we apply some minimal pressure on default priority
-	 * even on small cgroups. Stale objects are not only consuming memory
-	 * by themselves, but can also hold a reference to a dying cgroup,
-	 * preventing it from being reclaimed. A dying cgroup with all
-	 * corresponding structures like per-cpu stats and kmem caches
-	 * can be really big, so it may lead to a significant waste of memory.
-	 */
-	delta = max_t(unsigned long long, delta, min(freeable, batch_size));
-
 	total_scan += delta;
 	if (total_scan < 0) {
 		pr_err("shrink_slab: %pF negative objects to delete nr=%ld\n",