1 files changed, 95 insertions, 135 deletions

diff --git a/mm/khugepaged.c b/mm/khugepaged.c
index 16be62d493cd..01f71786d530 100644
--- a/mm/khugepaged.c
+++ b/mm/khugepaged.c
@@ -147,8 +147,7 @@ static ssize_t scan_sleep_millisecs_store(struct kobject *kobj,
 	return count;
 }
 static struct kobj_attribute scan_sleep_millisecs_attr =
-	__ATTR(scan_sleep_millisecs, 0644, scan_sleep_millisecs_show,
-	       scan_sleep_millisecs_store);
+	__ATTR_RW(scan_sleep_millisecs);
 
 static ssize_t alloc_sleep_millisecs_show(struct kobject *kobj,
 					  struct kobj_attribute *attr,
@@ -175,8 +174,7 @@ static ssize_t alloc_sleep_millisecs_store(struct kobject *kobj,
 	return count;
 }
 static struct kobj_attribute alloc_sleep_millisecs_attr =
-	__ATTR(alloc_sleep_millisecs, 0644, alloc_sleep_millisecs_show,
-	       alloc_sleep_millisecs_store);
+	__ATTR_RW(alloc_sleep_millisecs);
 
 static ssize_t pages_to_scan_show(struct kobject *kobj,
 				  struct kobj_attribute *attr,
@@ -200,8 +198,7 @@ static ssize_t pages_to_scan_store(struct kobject *kobj,
 	return count;
 }
 static struct kobj_attribute pages_to_scan_attr =
-	__ATTR(pages_to_scan, 0644, pages_to_scan_show,
-	       pages_to_scan_store);
+	__ATTR_RW(pages_to_scan);
 
 static ssize_t pages_collapsed_show(struct kobject *kobj,
 				    struct kobj_attribute *attr,
@@ -221,22 +218,21 @@ static ssize_t full_scans_show(struct kobject *kobj,
 static struct kobj_attribute full_scans_attr =
 	__ATTR_RO(full_scans);
 
-static ssize_t khugepaged_defrag_show(struct kobject *kobj,
-				      struct kobj_attribute *attr, char *buf)
+static ssize_t defrag_show(struct kobject *kobj,
+			   struct kobj_attribute *attr, char *buf)
 {
 	return single_hugepage_flag_show(kobj, attr, buf,
 					 TRANSPARENT_HUGEPAGE_DEFRAG_KHUGEPAGED_FLAG);
 }
-static ssize_t khugepaged_defrag_store(struct kobject *kobj,
-				       struct kobj_attribute *attr,
-				       const char *buf, size_t count)
+static ssize_t defrag_store(struct kobject *kobj,
+			    struct kobj_attribute *attr,
+			    const char *buf, size_t count)
 {
 	return single_hugepage_flag_store(kobj, attr, buf, count,
 				 TRANSPARENT_HUGEPAGE_DEFRAG_KHUGEPAGED_FLAG);
 }
 static struct kobj_attribute khugepaged_defrag_attr =
-	__ATTR(defrag, 0644, khugepaged_defrag_show,
-	       khugepaged_defrag_store);
+	__ATTR_RW(defrag);
 
 /*
  * max_ptes_none controls if khugepaged should collapse hugepages over
@@ -246,21 +242,21 @@ static struct kobj_attribute khugepaged_defrag_attr =
  * runs. Increasing max_ptes_none will instead potentially reduce the
  * free memory in the system during the khugepaged scan.
  */
-static ssize_t khugepaged_max_ptes_none_show(struct kobject *kobj,
-					     struct kobj_attribute *attr,
-					     char *buf)
+static ssize_t max_ptes_none_show(struct kobject *kobj,
+				  struct kobj_attribute *attr,
+				  char *buf)
 {
 	return sysfs_emit(buf, "%u\n", khugepaged_max_ptes_none);
 }
-static ssize_t khugepaged_max_ptes_none_store(struct kobject *kobj,
-					      struct kobj_attribute *attr,
-					      const char *buf, size_t count)
+static ssize_t max_ptes_none_store(struct kobject *kobj,
+				   struct kobj_attribute *attr,
+				   const char *buf, size_t count)
 {
 	int err;
 	unsigned long max_ptes_none;
 
 	err = kstrtoul(buf, 10, &max_ptes_none);
-	if (err || max_ptes_none > HPAGE_PMD_NR-1)
+	if (err || max_ptes_none > HPAGE_PMD_NR - 1)
 		return -EINVAL;
 
 	khugepaged_max_ptes_none = max_ptes_none;
@@ -268,25 +264,24 @@ static ssize_t khugepaged_max_ptes_none_store(struct kobject *kobj,
 	return count;
 }
 static struct kobj_attribute khugepaged_max_ptes_none_attr =
-	__ATTR(max_ptes_none, 0644, khugepaged_max_ptes_none_show,
-	       khugepaged_max_ptes_none_store);
+	__ATTR_RW(max_ptes_none);
 
-static ssize_t khugepaged_max_ptes_swap_show(struct kobject *kobj,
-					     struct kobj_attribute *attr,
-					     char *buf)
+static ssize_t max_ptes_swap_show(struct kobject *kobj,
+				  struct kobj_attribute *attr,
+				  char *buf)
 {
 	return sysfs_emit(buf, "%u\n", khugepaged_max_ptes_swap);
 }
 
-static ssize_t khugepaged_max_ptes_swap_store(struct kobject *kobj,
-					      struct kobj_attribute *attr,
-					      const char *buf, size_t count)
+static ssize_t max_ptes_swap_store(struct kobject *kobj,
+				   struct kobj_attribute *attr,
+				   const char *buf, size_t count)
 {
 	int err;
 	unsigned long max_ptes_swap;
 
 	err  = kstrtoul(buf, 10, &max_ptes_swap);
-	if (err || max_ptes_swap > HPAGE_PMD_NR-1)
+	if (err || max_ptes_swap > HPAGE_PMD_NR - 1)
 		return -EINVAL;
 
 	khugepaged_max_ptes_swap = max_ptes_swap;
@@ -295,25 +290,24 @@ static ssize_t khugepaged_max_ptes_swap_store(struct kobject *kobj,
 }
 
 static struct kobj_attribute khugepaged_max_ptes_swap_attr =
-	__ATTR(max_ptes_swap, 0644, khugepaged_max_ptes_swap_show,
-	       khugepaged_max_ptes_swap_store);
+	__ATTR_RW(max_ptes_swap);
 
-static ssize_t khugepaged_max_ptes_shared_show(struct kobject *kobj,
-					       struct kobj_attribute *attr,
-					       char *buf)
+static ssize_t max_ptes_shared_show(struct kobject *kobj,
+				    struct kobj_attribute *attr,
+				    char *buf)
 {
 	return sysfs_emit(buf, "%u\n", khugepaged_max_ptes_shared);
 }
 
-static ssize_t khugepaged_max_ptes_shared_store(struct kobject *kobj,
-					      struct kobj_attribute *attr,
-					      const char *buf, size_t count)
+static ssize_t max_ptes_shared_store(struct kobject *kobj,
+				     struct kobj_attribute *attr,
+				     const char *buf, size_t count)
 {
 	int err;
 	unsigned long max_ptes_shared;
 
 	err  = kstrtoul(buf, 10, &max_ptes_shared);
-	if (err || max_ptes_shared > HPAGE_PMD_NR-1)
+	if (err || max_ptes_shared > HPAGE_PMD_NR - 1)
 		return -EINVAL;
 
 	khugepaged_max_ptes_shared = max_ptes_shared;
@@ -322,8 +316,7 @@ static ssize_t khugepaged_max_ptes_shared_store(struct kobject *kobj,
 }
 
 static struct kobj_attribute khugepaged_max_ptes_shared_attr =
-	__ATTR(max_ptes_shared, 0644, khugepaged_max_ptes_shared_show,
-	       khugepaged_max_ptes_shared_store);
+	__ATTR_RW(max_ptes_shared);
 
 static struct attribute *khugepaged_attr[] = {
 	&khugepaged_defrag_attr.attr,
@@ -437,43 +430,6 @@ static inline int khugepaged_test_exit(struct mm_struct *mm)
 	return atomic_read(&mm->mm_users) == 0;
 }
 
-bool hugepage_vma_check(struct vm_area_struct *vma,
-			unsigned long vm_flags)
-{
-	if (!transhuge_vma_enabled(vma, vm_flags))
-		return false;
-
-	if (vm_flags & VM_NO_KHUGEPAGED)
-		return false;
-
-	/* Don't run khugepaged against DAX vma */
-	if (vma_is_dax(vma))
-		return false;
-
-	if (vma->vm_file && !IS_ALIGNED((vma->vm_start >> PAGE_SHIFT) -
-				vma->vm_pgoff, HPAGE_PMD_NR))
-		return false;
-
-	/* Enabled via shmem mount options or sysfs settings. */
-	if (shmem_file(vma->vm_file))
-		return shmem_huge_enabled(vma);
-
-	/* THP settings require madvise. */
-	if (!(vm_flags & VM_HUGEPAGE) && !khugepaged_always())
-		return false;
-
-	/* Only regular file is valid */
-	if (file_thp_enabled(vma))
-		return true;
-
-	if (!vma->anon_vma || !vma_is_anonymous(vma))
-		return false;
-	if (vma_is_temporary_stack(vma))
-		return false;
-
-	return true;
-}
-
 void __khugepaged_enter(struct mm_struct *mm)
 {
 	struct mm_slot *mm_slot;
@@ -509,10 +465,8 @@ void khugepaged_enter_vma(struct vm_area_struct *vma,
 			  unsigned long vm_flags)
 {
 	if (!test_bit(MMF_VM_HUGEPAGE, &vma->vm_mm->flags) &&
-	    khugepaged_enabled() &&
-	    (((vma->vm_start + ~HPAGE_PMD_MASK) & HPAGE_PMD_MASK) <
-	     (vma->vm_end & HPAGE_PMD_MASK))) {
-		if (hugepage_vma_check(vma, vm_flags))
+	    hugepage_flags_enabled()) {
+		if (hugepage_vma_check(vma, vm_flags, false, false))
 			__khugepaged_enter(vma->vm_mm);
 	}
 }
@@ -599,7 +553,7 @@ static int __collapse_huge_page_isolate(struct vm_area_struct *vma,
 	int none_or_zero = 0, shared = 0, result = 0, referenced = 0;
 	bool writable = false;
 
-	for (_pte = pte; _pte < pte+HPAGE_PMD_NR;
+	for (_pte = pte; _pte < pte + HPAGE_PMD_NR;
 	     _pte++, address += PAGE_SIZE) {
 		pte_t pteval = *_pte;
 		if (pte_none(pteval) || (pte_present(pteval) &&
@@ -618,7 +572,7 @@ static int __collapse_huge_page_isolate(struct vm_area_struct *vma,
 			goto out;
 		}
 		page = vm_normal_page(vma, address, pteval);
-		if (unlikely(!page)) {
+		if (unlikely(!page) || unlikely(is_zone_device_page(page))) {
 			result = SCAN_PAGE_NULL;
 			goto out;
 		}
@@ -762,7 +716,12 @@ static void __collapse_huge_page_copy(pte_t *pte, struct page *page,
 
 	list_for_each_entry_safe(src_page, tmp, compound_pagelist, lru) {
 		list_del(&src_page->lru);
-		release_pte_page(src_page);
+		mod_node_page_state(page_pgdat(src_page),
+				    NR_ISOLATED_ANON + page_is_file_lru(src_page),
+				    -compound_nr(src_page));
+		unlock_page(src_page);
+		free_swap_cache(src_page);
+		putback_lru_page(src_page);
 	}
 }
 
@@ -802,6 +761,10 @@ static bool khugepaged_scan_abort(int nid)
 	return false;
 }
 
+#define khugepaged_defrag()					\
+	(transparent_hugepage_flags &				\
+	 (1<<TRANSPARENT_HUGEPAGE_DEFRAG_KHUGEPAGED_FLAG))
+
 /* Defrag for khugepaged will enter direct reclaim/compaction if necessary */
 static inline gfp_t alloc_hugepage_khugepaged_gfpmask(void)
 {
@@ -899,7 +862,7 @@ static struct page *khugepaged_alloc_hugepage(bool *wait)
 			khugepaged_alloc_sleep();
 		} else
 			count_vm_event(THP_COLLAPSE_ALLOC);
-	} while (unlikely(!hpage) && likely(khugepaged_enabled()));
+	} while (unlikely(!hpage) && likely(hugepage_flags_enabled()));
 
 	return hpage;
 }
@@ -947,7 +910,6 @@ static int hugepage_vma_revalidate(struct mm_struct *mm, unsigned long address,
 		struct vm_area_struct **vmap)
 {
 	struct vm_area_struct *vma;
-	unsigned long hstart, hend;
 
 	if (unlikely(khugepaged_test_exit(mm)))
 		return SCAN_ANY_PROCESS;
@@ -956,13 +918,17 @@ static int hugepage_vma_revalidate(struct mm_struct *mm, unsigned long address,
 	if (!vma)
 		return SCAN_VMA_NULL;
 
-	hstart = (vma->vm_start + ~HPAGE_PMD_MASK) & HPAGE_PMD_MASK;
-	hend = vma->vm_end & HPAGE_PMD_MASK;
-	if (address < hstart || address + HPAGE_PMD_SIZE > hend)
+	if (!transhuge_vma_suitable(vma, address))
 		return SCAN_ADDRESS_RANGE;
-	if (!hugepage_vma_check(vma, vma->vm_flags))
+	if (!hugepage_vma_check(vma, vma->vm_flags, false, false))
 		return SCAN_VMA_CHECK;
-	/* Anon VMA expected */
+	/*
+	 * Anon VMA expected, the address may be unmapped then
+	 * remapped to file after khugepaged reaquired the mmap_lock.
+	 *
+	 * hugepage_vma_check may return true for qualified file
+	 * vmas.
+	 */
 	if (!vma->anon_vma || !vma_is_anonymous(vma))
 		return SCAN_VMA_CHECK;
 	return 0;
@@ -972,8 +938,8 @@ static int hugepage_vma_revalidate(struct mm_struct *mm, unsigned long address,
  * Bring missing pages in from swap, to complete THP collapse.
  * Only done if khugepaged_scan_pmd believes it is worthwhile.
  *
- * Called and returns without pte mapped or spinlocks held,
- * but with mmap_lock held to protect against vma changes.
+ * Called and returns without pte mapped or spinlocks held.
+ * Note that if false is returned, mmap_lock will be released.
  */
 
 static bool __collapse_huge_page_swapin(struct mm_struct *mm,
@@ -1000,27 +966,24 @@ static bool __collapse_huge_page_swapin(struct mm_struct *mm,
 			pte_unmap(vmf.pte);
 			continue;
 		}
-		swapped_in++;
 		ret = do_swap_page(&vmf);
 
-		/* do_swap_page returns VM_FAULT_RETRY with released mmap_lock */
+		/*
+		 * do_swap_page returns VM_FAULT_RETRY with released mmap_lock.
+		 * Note we treat VM_FAULT_RETRY as VM_FAULT_ERROR here because
+		 * we do not retry here and swap entry will remain in pagetable
+		 * resulting in later failure.
+		 */
 		if (ret & VM_FAULT_RETRY) {
-			mmap_read_lock(mm);
-			if (hugepage_vma_revalidate(mm, haddr, &vma)) {
-				/* vma is no longer available, don't continue to swapin */
-				trace_mm_collapse_huge_page_swapin(mm, swapped_in, referenced, 0);
-				return false;
-			}
-			/* check if the pmd is still valid */
-			if (mm_find_pmd(mm, haddr) != pmd) {
-				trace_mm_collapse_huge_page_swapin(mm, swapped_in, referenced, 0);
-				return false;
-			}
+			trace_mm_collapse_huge_page_swapin(mm, swapped_in, referenced, 0);
+			return false;
 		}
 		if (ret & VM_FAULT_ERROR) {
+			mmap_read_unlock(mm);
 			trace_mm_collapse_huge_page_swapin(mm, swapped_in, referenced, 0);
 			return false;
 		}
+		swapped_in++;
 	}
 
 	/* Drain LRU add pagevec to remove extra pin on the swapped in pages */
@@ -1086,13 +1049,12 @@ static void collapse_huge_page(struct mm_struct *mm,
 	}
 
 	/*
-	 * __collapse_huge_page_swapin always returns with mmap_lock locked.
-	 * If it fails, we release mmap_lock and jump out_nolock.
+	 * __collapse_huge_page_swapin will return with mmap_lock released
+	 * when it fails. So we jump out_nolock directly in that case.
 	 * Continuing to collapse causes inconsistency.
 	 */
 	if (unmapped && !__collapse_huge_page_swapin(mm, vma, address,
 						     pmd, referenced)) {
-		mmap_read_unlock(mm);
 		goto out_nolock;
 	}
 
@@ -1219,7 +1181,7 @@ static int khugepaged_scan_pmd(struct mm_struct *mm,
 
 	memset(khugepaged_node_load, 0, sizeof(khugepaged_node_load));
 	pte = pte_offset_map_lock(mm, pmd, address, &ptl);
-	for (_address = address, _pte = pte; _pte < pte+HPAGE_PMD_NR;
+	for (_address = address, _pte = pte; _pte < pte + HPAGE_PMD_NR;
 	     _pte++, _address += PAGE_SIZE) {
 		pte_t pteval = *_pte;
 		if (is_swap_pte(pteval)) {
@@ -1267,7 +1229,7 @@ static int khugepaged_scan_pmd(struct mm_struct *mm,
 			writable = true;
 
 		page = vm_normal_page(vma, _address, pteval);
-		if (unlikely(!page)) {
+		if (unlikely(!page) || unlikely(is_zone_device_page(page))) {
 			result = SCAN_PAGE_NULL;
 			goto out_unmap;
 		}
@@ -1309,7 +1271,7 @@ static int khugepaged_scan_pmd(struct mm_struct *mm,
 		/*
 		 * Check if the page has any GUP (or other external) pins.
 		 *
-		 * Here the check is racy it may see totmal_mapcount > refcount
+		 * Here the check is racy it may see total_mapcount > refcount
 		 * in some cases.
 		 * For example, one process with one forked child process.
 		 * The parent has the PMD split due to MADV_DONTNEED, then
@@ -1382,8 +1344,8 @@ static void collect_mm_slot(struct mm_slot *mm_slot)
  * Notify khugepaged that given addr of the mm is pte-mapped THP. Then
  * khugepaged should try to collapse the page table.
  */
-static int khugepaged_add_pte_mapped_thp(struct mm_struct *mm,
-					 unsigned long addr)
+static void khugepaged_add_pte_mapped_thp(struct mm_struct *mm,
+					  unsigned long addr)
 {
 	struct mm_slot *mm_slot;
 
@@ -1394,7 +1356,6 @@ static int khugepaged_add_pte_mapped_thp(struct mm_struct *mm,
 	if (likely(mm_slot && mm_slot->nr_pte_mapped_thp < MAX_PTE_MAPPED_THP))
 		mm_slot->pte_mapped_thp[mm_slot->nr_pte_mapped_thp++] = addr;
 	spin_unlock(&khugepaged_mm_lock);
-	return 0;
 }
 
 static void collapse_and_free_pmd(struct mm_struct *mm, struct vm_area_struct *vma,
@@ -1444,7 +1405,7 @@ void collapse_pte_mapped_thp(struct mm_struct *mm, unsigned long addr)
 	 * the valid THP. Add extra VM_HUGEPAGE so hugepage_vma_check()
 	 * will not fail the vma for missing VM_HUGEPAGE
 	 */
-	if (!hugepage_vma_check(vma, vma->vm_flags | VM_HUGEPAGE))
+	if (!hugepage_vma_check(vma, vma->vm_flags | VM_HUGEPAGE, false, false))
 		return;
 
 	/* Keep pmd pgtable for uffd-wp; see comment in retract_page_tables() */
@@ -1479,7 +1440,8 @@ void collapse_pte_mapped_thp(struct mm_struct *mm, unsigned long addr)
 			goto abort;
 
 		page = vm_normal_page(vma, addr, *pte);
-
+		if (WARN_ON_ONCE(page && is_zone_device_page(page)))
+			page = NULL;
 		/*
 		 * Note that uprobe, debugger, or MAP_PRIVATE may change the
 		 * page table, but the new page will not be a subpage of hpage.
@@ -1497,6 +1459,8 @@ void collapse_pte_mapped_thp(struct mm_struct *mm, unsigned long addr)
 		if (pte_none(*pte))
 			continue;
 		page = vm_normal_page(vma, addr, *pte);
+		if (WARN_ON_ONCE(page && is_zone_device_page(page)))
+			goto abort;
 		page_remove_rmap(page, vma, false);
 	}
 
@@ -1557,7 +1521,7 @@ static void retract_page_tables(struct address_space *mapping, pgoff_t pgoff)
 		 * mmap_write_lock(mm) as PMD-mapping is likely to be split
 		 * later.
 		 *
-		 * Not that vma->anon_vma check is racy: it can be set up after
+		 * Note that vma->anon_vma check is racy: it can be set up after
 		 * the check but before we took mmap_lock by the fault path.
 		 * But page lock would prevent establishing any new ptes of the
 		 * page, so we are safe.
@@ -1885,8 +1849,8 @@ out_unlock:
 
 	if (nr_none) {
 		__mod_lruvec_page_state(new_page, NR_FILE_PAGES, nr_none);
-		if (is_shmem)
-			__mod_lruvec_page_state(new_page, NR_SHMEM, nr_none);
+		/* nr_none is always 0 for non-shmem. */
+		__mod_lruvec_page_state(new_page, NR_SHMEM, nr_none);
 	}
 
 	/* Join all the small entries into a single multi-index entry */
@@ -1950,10 +1914,10 @@ xa_unlocked:
 
 		/* Something went wrong: roll back page cache changes */
 		xas_lock_irq(&xas);
-		mapping->nrpages -= nr_none;
-
-		if (is_shmem)
+		if (nr_none) {
+			mapping->nrpages -= nr_none;
 			shmem_uncharge(mapping->host, nr_none);
+		}
 
 		xas_set(&xas, start);
 		xas_for_each(&xas, page, end - 1) {
@@ -2131,22 +2095,18 @@ static unsigned int khugepaged_scan_mm_slot(unsigned int pages,
 			progress++;
 			break;
 		}
-		if (!hugepage_vma_check(vma, vma->vm_flags)) {
+		if (!hugepage_vma_check(vma, vma->vm_flags, false, false)) {
 skip:
 			progress++;
 			continue;
 		}
-		hstart = (vma->vm_start + ~HPAGE_PMD_MASK) & HPAGE_PMD_MASK;
-		hend = vma->vm_end & HPAGE_PMD_MASK;
-		if (hstart >= hend)
-			goto skip;
+		hstart = round_up(vma->vm_start, HPAGE_PMD_SIZE);
+		hend = round_down(vma->vm_end, HPAGE_PMD_SIZE);
 		if (khugepaged_scan.address > hend)
 			goto skip;
 		if (khugepaged_scan.address < hstart)
 			khugepaged_scan.address = hstart;
 		VM_BUG_ON(khugepaged_scan.address & ~HPAGE_PMD_MASK);
-		if (shmem_file(vma->vm_file) && !shmem_huge_enabled(vma))
-			goto skip;
 
 		while (khugepaged_scan.address < hend) {
 			int ret;
@@ -2216,7 +2176,7 @@ breakouterloop_mmap_lock:
 static int khugepaged_has_work(void)
 {
 	return !list_empty(&khugepaged_scan.mm_head) &&
-		khugepaged_enabled();
+		hugepage_flags_enabled();
 }
 
 static int khugepaged_wait_event(void)
@@ -2281,7 +2241,7 @@ static void khugepaged_wait_work(void)
 		return;
 	}
 
-	if (khugepaged_enabled())
+	if (hugepage_flags_enabled())
 		wait_event_freezable(khugepaged_wait, khugepaged_wait_event());
 }
 
@@ -2312,7 +2272,7 @@ static void set_recommended_min_free_kbytes(void)
 	int nr_zones = 0;
 	unsigned long recommended_min;
 
-	if (!khugepaged_enabled()) {
+	if (!hugepage_flags_enabled()) {
 		calculate_min_free_kbytes();
 		goto update_wmarks;
 	}
@@ -2362,7 +2322,7 @@ int start_stop_khugepaged(void)
 	int err = 0;
 
 	mutex_lock(&khugepaged_mutex);
-	if (khugepaged_enabled()) {
+	if (hugepage_flags_enabled()) {
 		if (!khugepaged_thread)
 			khugepaged_thread = kthread_run(khugepaged, NULL,
 							"khugepaged");
@@ -2388,7 +2348,7 @@ fail:
 void khugepaged_min_free_kbytes_update(void)
 {
 	mutex_lock(&khugepaged_mutex);
-	if (khugepaged_enabled() && khugepaged_thread)
+	if (hugepage_flags_enabled() && khugepaged_thread)
 		set_recommended_min_free_kbytes();
 	mutex_unlock(&khugepaged_mutex);
 }