Merge tag 'mm-stable-2023-09-04-14-00' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

Pull more MM updates from Andrew Morton:

 - Stefan Roesch has added ksm statistics to /proc/pid/smaps

 - Also a number of singleton patches, mainly cleanups and leftovers

* tag 'mm-stable-2023-09-04-14-00' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm:
  mm/kmemleak: move up cond_resched() call in page scanning loop
  mm: page_alloc: remove stale CMA guard code
  MAINTAINERS: add rmap.h to mm entry
  rmap: remove anon_vma_link() nommu stub
  proc/ksm: add ksm stats to /proc/pid/smaps
  mm/hwpoison: rename hwp_walk* to hwpoison_walk*
  mm: memory-failure: add PageOffline() check

7 files changed, 29 insertions, 30 deletions

diff --git a/Documentation/filesystems/proc.rst b/Documentation/filesystems/proc.rst
index 1f9615553b8273..2b59cff8be1798 100644
--- a/Documentation/filesystems/proc.rst
+++ b/Documentation/filesystems/proc.rst
@@ -461,6 +461,7 @@ Memory Area, or VMA) there is a series of lines such as the following::
     Private_Dirty:         0 kB
     Referenced:          892 kB
     Anonymous:             0 kB
+    KSM:                   0 kB
     LazyFree:              0 kB
     AnonHugePages:         0 kB
     ShmemPmdMapped:        0 kB
@@ -501,6 +502,9 @@ accessed.
 a mapping associated with a file may contain anonymous pages: when MAP_PRIVATE
 and a page is modified, the file page is replaced by a private anonymous copy.
 
+"KSM" reports how many of the pages are KSM pages. Note that KSM-placed zeropages
+are not included, only actual KSM pages.
+
 "LazyFree" shows the amount of memory which is marked by madvise(MADV_FREE).
 The memory isn't freed immediately with madvise(). It's freed in memory
 pressure if the memory is clean. Please note that the printed value might
diff --git a/MAINTAINERS b/MAINTAINERS
index 9c186c214c54e6..0e4ad56821a010 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -13742,6 +13742,7 @@ F:	include/linux/memory_hotplug.h
 F:	include/linux/mm.h
 F:	include/linux/mmzone.h
 F:	include/linux/pagewalk.h
+F:	include/linux/rmap.h
 F:	include/trace/events/ksm.h
 F:	mm/
 F:	tools/mm/
diff --git a/fs/proc/task_mmu.c b/fs/proc/task_mmu.c
index 0f2aa36a9913b5..3dd5be96691b4c 100644
--- a/fs/proc/task_mmu.c
+++ b/fs/proc/task_mmu.c
@@ -4,6 +4,7 @@
 #include <linux/hugetlb.h>
 #include <linux/huge_mm.h>
 #include <linux/mount.h>
+#include <linux/ksm.h>
 #include <linux/seq_file.h>
 #include <linux/highmem.h>
 #include <linux/ptrace.h>
@@ -396,6 +397,7 @@ struct mem_size_stats {
 	unsigned long swap;
 	unsigned long shared_hugetlb;
 	unsigned long private_hugetlb;
+	unsigned long ksm;
 	u64 pss;
 	u64 pss_anon;
 	u64 pss_file;
@@ -452,6 +454,9 @@ static void smaps_account(struct mem_size_stats *mss, struct page *page,
 			mss->lazyfree += size;
 	}
 
+	if (PageKsm(page))
+		mss->ksm += size;
+
 	mss->resident += size;
 	/* Accumulate the size in pages that have been accessed. */
 	if (young || page_is_young(page) || PageReferenced(page))
@@ -825,6 +830,7 @@ static void __show_smap(struct seq_file *m, const struct mem_size_stats *mss,
 	SEQ_PUT_DEC(" kB\nPrivate_Dirty:  ", mss->private_dirty);
 	SEQ_PUT_DEC(" kB\nReferenced:     ", mss->referenced);
 	SEQ_PUT_DEC(" kB\nAnonymous:      ", mss->anonymous);
+	SEQ_PUT_DEC(" kB\nKSM:            ", mss->ksm);
 	SEQ_PUT_DEC(" kB\nLazyFree:       ", mss->lazyfree);
 	SEQ_PUT_DEC(" kB\nAnonHugePages:  ", mss->anonymous_thp);
 	SEQ_PUT_DEC(" kB\nShmemPmdMapped: ", mss->shmem_thp);
diff --git a/include/linux/rmap.h b/include/linux/rmap.h
index a3825ce81102cf..51cc21ebb568b0 100644
--- a/include/linux/rmap.h
+++ b/include/linux/rmap.h
@@ -479,7 +479,6 @@ struct anon_vma *folio_lock_anon_vma_read(struct folio *folio,
 
 #define anon_vma_init()		do {} while (0)
 #define anon_vma_prepare(vma)	(0)
-#define anon_vma_link(vma)	do {} while (0)
 
 static inline int folio_referenced(struct folio *folio, int is_locked,
 				  struct mem_cgroup *memcg,
diff --git a/mm/kmemleak.c b/mm/kmemleak.c
index 2918150e31bd9c..54c2c90d3abc9d 100644
--- a/mm/kmemleak.c
+++ b/mm/kmemleak.c
@@ -1584,6 +1584,9 @@ static void kmemleak_scan(void)
 		for (pfn = start_pfn; pfn < end_pfn; pfn++) {
 			struct page *page = pfn_to_online_page(pfn);
 
+			if (!(pfn & 63))
+				cond_resched();
+
 			if (!page)
 				continue;
 
@@ -1594,8 +1597,6 @@ static void kmemleak_scan(void)
 			if (page_count(page) == 0)
 				continue;
 			scan_block(page, page + 1, NULL);
-			if (!(pfn & 63))
-				cond_resched();
 		}
 	}
 	put_online_mems();
diff --git a/mm/memory-failure.c b/mm/memory-failure.c
index 881c35ef1daa88..7b01fffe7a791b 100644
--- a/mm/memory-failure.c
+++ b/mm/memory-failure.c
@@ -717,7 +717,7 @@ static void collect_procs(struct page *page, struct list_head *tokill,
 		collect_procs_file(page, tokill, force_early);
 }
 
-struct hwp_walk {
+struct hwpoison_walk {
 	struct to_kill tk;
 	unsigned long pfn;
 	int flags;
@@ -752,7 +752,7 @@ static int check_hwpoisoned_entry(pte_t pte, unsigned long addr, short shift,
 
 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
 static int check_hwpoisoned_pmd_entry(pmd_t *pmdp, unsigned long addr,
-				      struct hwp_walk *hwp)
+				      struct hwpoison_walk *hwp)
 {
 	pmd_t pmd = *pmdp;
 	unsigned long pfn;
@@ -770,7 +770,7 @@ static int check_hwpoisoned_pmd_entry(pmd_t *pmdp, unsigned long addr,
 }
 #else
 static int check_hwpoisoned_pmd_entry(pmd_t *pmdp, unsigned long addr,
-				      struct hwp_walk *hwp)
+				      struct hwpoison_walk *hwp)
 {
 	return 0;
 }
@@ -779,7 +779,7 @@ static int check_hwpoisoned_pmd_entry(pmd_t *pmdp, unsigned long addr,
 static int hwpoison_pte_range(pmd_t *pmdp, unsigned long addr,
 			      unsigned long end, struct mm_walk *walk)
 {
-	struct hwp_walk *hwp = walk->private;
+	struct hwpoison_walk *hwp = walk->private;
 	int ret = 0;
 	pte_t *ptep, *mapped_pte;
 	spinlock_t *ptl;
@@ -813,7 +813,7 @@ static int hwpoison_hugetlb_range(pte_t *ptep, unsigned long hmask,
 			    unsigned long addr, unsigned long end,
 			    struct mm_walk *walk)
 {
-	struct hwp_walk *hwp = walk->private;
+	struct hwpoison_walk *hwp = walk->private;
 	pte_t pte = huge_ptep_get(ptep);
 	struct hstate *h = hstate_vma(walk->vma);
 
@@ -824,7 +824,7 @@ static int hwpoison_hugetlb_range(pte_t *ptep, unsigned long hmask,
 #define hwpoison_hugetlb_range	NULL
 #endif
 
-static const struct mm_walk_ops hwp_walk_ops = {
+static const struct mm_walk_ops hwpoison_walk_ops = {
 	.pmd_entry = hwpoison_pte_range,
 	.hugetlb_entry = hwpoison_hugetlb_range,
 	.walk_lock = PGWALK_RDLOCK,
@@ -847,7 +847,7 @@ static int kill_accessing_process(struct task_struct *p, unsigned long pfn,
 				  int flags)
 {
 	int ret;
-	struct hwp_walk priv = {
+	struct hwpoison_walk priv = {
 		.pfn = pfn,
 	};
 	priv.tk.tsk = p;
@@ -856,7 +856,7 @@ static int kill_accessing_process(struct task_struct *p, unsigned long pfn,
 		return -EFAULT;
 
 	mmap_read_lock(p->mm);
-	ret = walk_page_range(p->mm, 0, TASK_SIZE, &hwp_walk_ops,
+	ret = walk_page_range(p->mm, 0, TASK_SIZE, &hwpoison_walk_ops,
 			      (void *)&priv);
 	if (ret == 1 && priv.tk.addr)
 		kill_proc(&priv.tk, pfn, flags);
@@ -1562,7 +1562,7 @@ static bool hwpoison_user_mappings(struct page *p, unsigned long pfn,
 	 * Here we are interested only in user-mapped pages, so skip any
 	 * other types of pages.
 	 */
-	if (PageReserved(p) || PageSlab(p) || PageTable(p))
+	if (PageReserved(p) || PageSlab(p) || PageTable(p) || PageOffline(p))
 		return true;
 	if (!(PageLRU(hpage) || PageHuge(p)))
 		return true;
@@ -2533,7 +2533,8 @@ int unpoison_memory(unsigned long pfn)
 		goto unlock_mutex;
 	}
 
-	if (folio_test_slab(folio) || PageTable(&folio->page) || folio_test_reserved(folio))
+	if (folio_test_slab(folio) || PageTable(&folio->page) ||
+	    folio_test_reserved(folio) || PageOffline(&folio->page))
 		goto unlock_mutex;
 
 	/*
diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index 452459836b7118..0c5be12f933636 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -2641,12 +2641,6 @@ struct page *rmqueue_buddy(struct zone *preferred_zone, struct zone *zone,
 	do {
 		page = NULL;
 		spin_lock_irqsave(&zone->lock, flags);
-		/*
-		 * order-0 request can reach here when the pcplist is skipped
-		 * due to non-CMA allocation context. HIGHATOMIC area is
-		 * reserved for high-order atomic allocation, so order-0
-		 * request should skip it.
-		 */
 		if (alloc_flags & ALLOC_HIGHATOMIC)
 			page = __rmqueue_smallest(zone, order, MIGRATE_HIGHATOMIC);
 		if (!page) {
@@ -2780,17 +2774,10 @@ struct page *rmqueue(struct zone *preferred_zone,
 	WARN_ON_ONCE((gfp_flags & __GFP_NOFAIL) && (order > 1));
 
 	if (likely(pcp_allowed_order(order))) {
-		/*
-		 * MIGRATE_MOVABLE pcplist could have the pages on CMA area and
-		 * we need to skip it when CMA area isn't allowed.
-		 */
-		if (!IS_ENABLED(CONFIG_CMA) || alloc_flags & ALLOC_CMA ||
-				migratetype != MIGRATE_MOVABLE) {
-			page = rmqueue_pcplist(preferred_zone, zone, order,
-					migratetype, alloc_flags);
-			if (likely(page))
-				goto out;
-		}
+		page = rmqueue_pcplist(preferred_zone, zone, order,
+				       migratetype, alloc_flags);
+		if (likely(page))
+			goto out;
 	}
 
 	page = rmqueue_buddy(preferred_zone, zone, order, alloc_flags,