1 files changed, 58 insertions, 71 deletions

diff --git a/mm/page_idle.c b/mm/page_idle.c
index b9e4b42b33ab..96bb94c7b6c3 100644
--- a/mm/page_idle.c
+++ b/mm/page_idle.c
@@ -4,6 +4,7 @@
 #include <linux/fs.h>
 #include <linux/sysfs.h>
 #include <linux/kobject.h>
+#include <linux/memory_hotplug.h>
 #include <linux/mm.h>
 #include <linux/mmzone.h>
 #include <linux/pagemap.h>
@@ -12,6 +13,8 @@
 #include <linux/page_ext.h>
 #include <linux/page_idle.h>
 
+#include "internal.h"
+
 #define BITMAP_CHUNK_SIZE	sizeof(u64)
 #define BITMAP_CHUNK_BITS	(BITMAP_CHUNK_SIZE * BITS_PER_BYTE)
 
@@ -28,38 +31,29 @@
  *
  * This function tries to get a user memory page by pfn as described above.
  */
-static struct page *page_idle_get_page(unsigned long pfn)
+static struct folio *page_idle_get_folio(unsigned long pfn)
 {
-	struct page *page;
-	struct zone *zone;
+	struct page *page = pfn_to_online_page(pfn);
+	struct folio *folio;
 
-	if (!pfn_valid(pfn))
+	if (!page || PageTail(page))
 		return NULL;
 
-	page = pfn_to_page(pfn);
-	if (!page || !PageLRU(page) ||
-	    !get_page_unless_zero(page))
+	folio = page_folio(page);
+	if (!folio_test_lru(folio) || !folio_try_get(folio))
 		return NULL;
-
-	zone = page_zone(page);
-	spin_lock_irq(zone_lru_lock(zone));
-	if (unlikely(!PageLRU(page))) {
-		put_page(page);
-		page = NULL;
+	if (unlikely(page_folio(page) != folio || !folio_test_lru(folio))) {
+		folio_put(folio);
+		folio = NULL;
 	}
-	spin_unlock_irq(zone_lru_lock(zone));
-	return page;
+	return folio;
 }
 
-static bool page_idle_clear_pte_refs_one(struct page *page,
+static bool page_idle_clear_pte_refs_one(struct folio *folio,
 					struct vm_area_struct *vma,
 					unsigned long addr, void *arg)
 {
-	struct page_vma_mapped_walk pvmw = {
-		.page = page,
-		.vma = vma,
-		.address = addr,
-	};
+	DEFINE_FOLIO_VMA_WALK(pvmw, folio, vma, addr, 0);
 	bool referenced = false;
 
 	while (page_vma_mapped_walk(&pvmw)) {
@@ -68,12 +62,20 @@ static bool page_idle_clear_pte_refs_one(struct page *page,
 			/*
 			 * For PTE-mapped THP, one sub page is referenced,
 			 * the whole THP is referenced.
+			 *
+			 * PFN swap PTEs, such as device-exclusive ones, that
+			 * actually map pages are "old" from a CPU perspective.
+			 * The MMU notifier takes care of any device aspects.
 			 */
-			if (ptep_clear_young_notify(vma, addr, pvmw.pte))
-				referenced = true;
+			if (likely(pte_present(ptep_get(pvmw.pte))))
+				referenced |= ptep_test_and_clear_young(vma, addr, pvmw.pte);
+			referenced |= mmu_notifier_clear_young(vma->vm_mm, addr, addr + PAGE_SIZE);
 		} else if (IS_ENABLED(CONFIG_TRANSPARENT_HUGEPAGE)) {
-			if (pmdp_clear_young_notify(vma, addr, pvmw.pmd))
-				referenced = true;
+			pmd_t pmdval = pmdp_get(pvmw.pmd);
+
+			if (likely(pmd_present(pmdval)))
+				referenced |= pmdp_clear_young_notify(vma, addr, pvmw.pmd);
+			referenced |= mmu_notifier_clear_young(vma->vm_mm, addr, addr + PMD_SIZE);
 		} else {
 			/* unexpected pmd-mapped page? */
 			WARN_ON_ONCE(1);
@@ -81,49 +83,44 @@ static bool page_idle_clear_pte_refs_one(struct page *page,
 	}
 
 	if (referenced) {
-		clear_page_idle(page);
+		folio_clear_idle(folio);
 		/*
 		 * We cleared the referenced bit in a mapping to this page. To
 		 * avoid interference with page reclaim, mark it young so that
-		 * page_referenced() will return > 0.
+		 * folio_referenced() will return > 0.
 		 */
-		set_page_young(page);
+		folio_set_young(folio);
 	}
 	return true;
 }
 
-static void page_idle_clear_pte_refs(struct page *page)
+static void page_idle_clear_pte_refs(struct folio *folio)
 {
 	/*
-	 * Since rwc.arg is unused, rwc is effectively immutable, so we
-	 * can make it static const to save some cycles and stack.
+	 * Since rwc.try_lock is unused, rwc is effectively immutable, so we
+	 * can make it static to save some cycles and stack.
 	 */
-	static const struct rmap_walk_control rwc = {
+	static struct rmap_walk_control rwc = {
 		.rmap_one = page_idle_clear_pte_refs_one,
-		.anon_lock = page_lock_anon_vma_read,
+		.anon_lock = folio_lock_anon_vma_read,
 	};
-	bool need_lock;
 
-	if (!page_mapped(page) ||
-	    !page_rmapping(page))
+	if (!folio_mapped(folio) || !folio_raw_mapping(folio))
 		return;
 
-	need_lock = !PageAnon(page) || PageKsm(page);
-	if (need_lock && !trylock_page(page))
+	if (!folio_trylock(folio))
 		return;
 
-	rmap_walk(page, (struct rmap_walk_control *)&rwc);
-
-	if (need_lock)
-		unlock_page(page);
+	rmap_walk(folio, &rwc);
+	folio_unlock(folio);
 }
 
 static ssize_t page_idle_bitmap_read(struct file *file, struct kobject *kobj,
-				     struct bin_attribute *attr, char *buf,
+				     const struct bin_attribute *attr, char *buf,
 				     loff_t pos, size_t count)
 {
 	u64 *out = (u64 *)buf;
-	struct page *page;
+	struct folio *folio;
 	unsigned long pfn, end_pfn;
 	int bit;
 
@@ -136,25 +133,25 @@ static ssize_t page_idle_bitmap_read(struct file *file, struct kobject *kobj,
 
 	end_pfn = pfn + count * BITS_PER_BYTE;
 	if (end_pfn > max_pfn)
-		end_pfn = ALIGN(max_pfn, BITMAP_CHUNK_BITS);
+		end_pfn = max_pfn;
 
 	for (; pfn < end_pfn; pfn++) {
 		bit = pfn % BITMAP_CHUNK_BITS;
 		if (!bit)
 			*out = 0ULL;
-		page = page_idle_get_page(pfn);
-		if (page) {
-			if (page_is_idle(page)) {
+		folio = page_idle_get_folio(pfn);
+		if (folio) {
+			if (folio_test_idle(folio)) {
 				/*
 				 * The page might have been referenced via a
 				 * pte, in which case it is not idle. Clear
 				 * refs and recheck.
 				 */
-				page_idle_clear_pte_refs(page);
-				if (page_is_idle(page))
+				page_idle_clear_pte_refs(folio);
+				if (folio_test_idle(folio))
 					*out |= 1ULL << bit;
 			}
-			put_page(page);
+			folio_put(folio);
 		}
 		if (bit == BITMAP_CHUNK_BITS - 1)
 			out++;
@@ -164,11 +161,11 @@ static ssize_t page_idle_bitmap_read(struct file *file, struct kobject *kobj,
 }
 
 static ssize_t page_idle_bitmap_write(struct file *file, struct kobject *kobj,
-				      struct bin_attribute *attr, char *buf,
+				      const struct bin_attribute *attr, char *buf,
 				      loff_t pos, size_t count)
 {
 	const u64 *in = (u64 *)buf;
-	struct page *page;
+	struct folio *folio;
 	unsigned long pfn, end_pfn;
 	int bit;
 
@@ -181,16 +178,16 @@ static ssize_t page_idle_bitmap_write(struct file *file, struct kobject *kobj,
 
 	end_pfn = pfn + count * BITS_PER_BYTE;
 	if (end_pfn > max_pfn)
-		end_pfn = ALIGN(max_pfn, BITMAP_CHUNK_BITS);
+		end_pfn = max_pfn;
 
 	for (; pfn < end_pfn; pfn++) {
 		bit = pfn % BITMAP_CHUNK_BITS;
 		if ((*in >> bit) & 1) {
-			page = page_idle_get_page(pfn);
-			if (page) {
-				page_idle_clear_pte_refs(page);
-				set_page_idle(page);
-				put_page(page);
+			folio = page_idle_get_folio(pfn);
+			if (folio) {
+				page_idle_clear_pte_refs(folio);
+				folio_set_idle(folio);
+				folio_put(folio);
 			}
 		}
 		if (bit == BITMAP_CHUNK_BITS - 1)
@@ -200,11 +197,11 @@ static ssize_t page_idle_bitmap_write(struct file *file, struct kobject *kobj,
 	return (char *)in - buf;
 }
 
-static struct bin_attribute page_idle_bitmap_attr =
+static const struct bin_attribute page_idle_bitmap_attr =
 		__BIN_ATTR(bitmap, 0600,
 			   page_idle_bitmap_read, page_idle_bitmap_write, 0);
 
-static struct bin_attribute *page_idle_bin_attrs[] = {
+static const struct bin_attribute *const page_idle_bin_attrs[] = {
 	&page_idle_bitmap_attr,
 	NULL,
 };
@@ -214,16 +211,6 @@ static const struct attribute_group page_idle_attr_group = {
 	.name = "page_idle",
 };
 
-#ifndef CONFIG_64BIT
-static bool need_page_idle(void)
-{
-	return true;
-}
-struct page_ext_operations page_idle_ops = {
-	.need = need_page_idle,
-};
-#endif
-
 static int __init page_idle_init(void)
 {
 	int err;