Merge tag 'mm-stable-2023-11-01-14-33' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

Pull MM updates from Andrew Morton:
 "Many singleton patches against the MM code. The patch series which are
  included in this merge do the following:

   - Kemeng Shi has contributed some compation maintenance work in the
     series 'Fixes and cleanups to compaction'

   - Joel Fernandes has a patchset ('Optimize mremap during mutual
     alignment within PMD') which fixes an obscure issue with mremap()'s
     pagetable handling during a subsequent exec(), based upon an
     implementation which Linus suggested

   - More DAMON/DAMOS maintenance and feature work from SeongJae Park i
     the following patch series:

	mm/damon: misc fixups for documents, comments and its tracepoint
	mm/damon: add a tracepoint for damos apply target regions
	mm/damon: provide pseudo-moving sum based access rate
	mm/damon: implement DAMOS apply intervals
	mm/damon/core-test: Fix memory leaks in core-test
	mm/damon/sysfs-schemes: Do DAMOS tried regions update for only one apply interval

   - In the series 'Do not try to access unaccepted memory' Adrian
     Hunter provides some fixups for the recently-added 'unaccepted
     memory' feature. To increase the feature's checking coverage. 'Plug
     a few gaps where RAM is exposed without checking if it is
     unaccepted memory'

   - In the series 'cleanups for lockless slab shrink' Qi Zheng has done
     some maintenance work which is preparation for the lockless slab
     shrinking code

   - Qi Zheng has redone the earlier (and reverted) attempt to make slab
     shrinking lockless in the series 'use refcount+RCU method to
     implement lockless slab shrink'

   - David Hildenbrand contributes some maintenance work for the rmap
     code in the series 'Anon rmap cleanups'

   - Kefeng Wang does more folio conversions and some maintenance work
     in the migration code. Series 'mm: migrate: more folio conversion
     and unification'

   - Matthew Wilcox has fixed an issue in the buffer_head code which was
     causing long stalls under some heavy memory/IO loads. Some cleanups
     were added on the way. Series 'Add and use bdev_getblk()'

   - In the series 'Use nth_page() in place of direct struct page
     manipulation' Zi Yan has fixed a potential issue with the direct
     manipulation of hugetlb page frames

   - In the series 'mm: hugetlb: Skip initialization of gigantic tail
     struct pages if freed by HVO' has improved our handling of gigantic
     pages in the hugetlb vmmemmep optimizaton code. This provides
     significant boot time improvements when significant amounts of
     gigantic pages are in use

   - Matthew Wilcox has sent the series 'Small hugetlb cleanups' - code
     rationalization and folio conversions in the hugetlb code

   - Yin Fengwei has improved mlock()'s handling of large folios in the
     series 'support large folio for mlock'

   - In the series 'Expose swapcache stat for memcg v1' Liu Shixin has
     added statistics for memcg v1 users which are available (and
     useful) under memcg v2

   - Florent Revest has enhanced the MDWE (Memory-Deny-Write-Executable)
     prctl so that userspace may direct the kernel to not automatically
     propagate the denial to child processes. The series is named 'MDWE
     without inheritance'

   - Kefeng Wang has provided the series 'mm: convert numa balancing
     functions to use a folio' which does what it says

   - In the series 'mm/ksm: add fork-exec support for prctl' Stefan
     Roesch makes is possible for a process to propagate KSM treatment
     across exec()

   - Huang Ying has enhanced memory tiering's calculation of memory
     distances. This is used to permit the dax/kmem driver to use 'high
     bandwidth memory' in addition to Optane Data Center Persistent
     Memory Modules (DCPMM). The series is named 'memory tiering:
     calculate abstract distance based on ACPI HMAT'

   - In the series 'Smart scanning mode for KSM' Stefan Roesch has
     optimized KSM by teaching it to retain and use some historical
     information from previous scans

   - Yosry Ahmed has fixed some inconsistencies in memcg statistics in
     the series 'mm: memcg: fix tracking of pending stats updates
     values'

   - In the series 'Implement IOCTL to get and optionally clear info
     about PTEs' Peter Xu has added an ioctl to /proc/<pid>/pagemap
     which permits us to atomically read-then-clear page softdirty
     state. This is mainly used by CRIU

   - Hugh Dickins contributed the series 'shmem,tmpfs: general
     maintenance', a bunch of relatively minor maintenance tweaks to
     this code

   - Matthew Wilcox has increased the use of the VMA lock over
     file-backed page faults in the series 'Handle more faults under the
     VMA lock'. Some rationalizations of the fault path became possible
     as a result

   - In the series 'mm/rmap: convert page_move_anon_rmap() to
     folio_move_anon_rmap()' David Hildenbrand has implemented some
     cleanups and folio conversions

   - In the series 'various improvements to the GUP interface' Lorenzo
     Stoakes has simplified and improved the GUP interface with an eye
     to providing groundwork for future improvements

   - Andrey Konovalov has sent along the series 'kasan: assorted fixes
     and improvements' which does those things

   - Some page allocator maintenance work from Kemeng Shi in the series
     'Two minor cleanups to break_down_buddy_pages'

   - In thes series 'New selftest for mm' Breno Leitao has developed
     another MM self test which tickles a race we had between madvise()
     and page faults

   - In the series 'Add folio_end_read' Matthew Wilcox provides cleanups
     and an optimization to the core pagecache code

   - Nhat Pham has added memcg accounting for hugetlb memory in the
     series 'hugetlb memcg accounting'

   - Cleanups and rationalizations to the pagemap code from Lorenzo
     Stoakes, in the series 'Abstract vma_merge() and split_vma()'

   - Audra Mitchell has fixed issues in the procfs page_owner code's new
     timestamping feature which was causing some misbehaviours. In the
     series 'Fix page_owner's use of free timestamps'

   - Lorenzo Stoakes has fixed the handling of new mappings of sealed
     files in the series 'permit write-sealed memfd read-only shared
     mappings'

   - Mike Kravetz has optimized the hugetlb vmemmap optimization in the
     series 'Batch hugetlb vmemmap modification operations'

   - Some buffer_head folio conversions and cleanups from Matthew Wilcox
     in the series 'Finish the create_empty_buffers() transition'

   - As a page allocator performance optimization Huang Ying has added
     automatic tuning to the allocator's per-cpu-pages feature, in the
     series 'mm: PCP high auto-tuning'

   - Roman Gushchin has contributed the patchset 'mm: improve
     performance of accounted kernel memory allocations' which improves
     their performance by ~30% as measured by a micro-benchmark

   - folio conversions from Kefeng Wang in the series 'mm: convert page
     cpupid functions to folios'

   - Some kmemleak fixups in Liu Shixin's series 'Some bugfix about
     kmemleak'

   - Qi Zheng has improved our handling of memoryless nodes by keeping
     them off the allocation fallback list. This is done in the series
     'handle memoryless nodes more appropriately'

   - khugepaged conversions from Vishal Moola in the series 'Some
     khugepaged folio conversions'"

[ bcachefs conflicts with the dynamically allocated shrinkers have been
  resolved as per Stephen Rothwell in

     https://lore.kernel.org/all/20230913093553.4290421e@canb.auug.org.au/

  with help from Qi Zheng.

  The clone3 test filtering conflict was half-arsed by yours truly ]

* tag 'mm-stable-2023-11-01-14-33' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (406 commits)
  mm/damon/sysfs: update monitoring target regions for online input commit
  mm/damon/sysfs: remove requested targets when online-commit inputs
  selftests: add a sanity check for zswap
  Documentation: maple_tree: fix word spelling error
  mm/vmalloc: fix the unchecked dereference warning in vread_iter()
  zswap: export compression failure stats
  Documentation: ubsan: drop "the" from article title
  mempolicy: migration attempt to match interleave nodes
  mempolicy: mmap_lock is not needed while migrating folios
  mempolicy: alloc_pages_mpol() for NUMA policy without vma
  mm: add page_rmappable_folio() wrapper
  mempolicy: remove confusing MPOL_MF_LAZY dead code
  mempolicy: mpol_shared_policy_init() without pseudo-vma
  mempolicy trivia: use pgoff_t in shared mempolicy tree
  mempolicy trivia: slightly more consistent naming
  mempolicy trivia: delete those ancient pr_debug()s
  mempolicy: fix migrate_pages(2) syscall return nr_failed
  kernfs: drop shared NUMA mempolicy hooks
  hugetlbfs: drop shared NUMA mempolicy pretence
  mm/damon/sysfs-test: add a unit test for damon_sysfs_set_targets()
  ...

1 files changed, 267 insertions, 76 deletions

diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index 85741403948f..733732e7e0ba 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -52,6 +52,7 @@
 #include <linux/psi.h>
 #include <linux/khugepaged.h>
 #include <linux/delayacct.h>
+#include <linux/cacheinfo.h>
 #include <asm/div64.h>
 #include "internal.h"
 #include "shuffle.h"
@@ -1078,6 +1079,7 @@ static __always_inline bool free_pages_prepare(struct page *page,
 	int bad = 0;
 	bool skip_kasan_poison = should_skip_kasan_poison(page, fpi_flags);
 	bool init = want_init_on_free();
+	bool compound = PageCompound(page);
 
 	VM_BUG_ON_PAGE(PageTail(page), page);
 
@@ -1096,16 +1098,15 @@ static __always_inline bool free_pages_prepare(struct page *page,
 		return false;
 	}
 
+	VM_BUG_ON_PAGE(compound && compound_order(page) != order, page);
+
 	/*
 	 * Check tail pages before head page information is cleared to
 	 * avoid checking PageCompound for order-0 pages.
 	 */
 	if (unlikely(order)) {
-		bool compound = PageCompound(page);
 		int i;
 
-		VM_BUG_ON_PAGE(compound && compound_order(page) != order, page);
-
 		if (compound)
 			page[1].flags &= ~PAGE_FLAGS_SECOND;
 		for (i = 1; i < (1 << order); i++) {
@@ -2156,6 +2157,40 @@ static int rmqueue_bulk(struct zone *zone, unsigned int order,
 	return i;
 }
 
+/*
+ * Called from the vmstat counter updater to decay the PCP high.
+ * Return whether there are addition works to do.
+ */
+int decay_pcp_high(struct zone *zone, struct per_cpu_pages *pcp)
+{
+	int high_min, to_drain, batch;
+	int todo = 0;
+
+	high_min = READ_ONCE(pcp->high_min);
+	batch = READ_ONCE(pcp->batch);
+	/*
+	 * Decrease pcp->high periodically to try to free possible
+	 * idle PCP pages.  And, avoid to free too many pages to
+	 * control latency.  This caps pcp->high decrement too.
+	 */
+	if (pcp->high > high_min) {
+		pcp->high = max3(pcp->count - (batch << CONFIG_PCP_BATCH_SCALE_MAX),
+				 pcp->high - (pcp->high >> 3), high_min);
+		if (pcp->high > high_min)
+			todo++;
+	}
+
+	to_drain = pcp->count - pcp->high;
+	if (to_drain > 0) {
+		spin_lock(&pcp->lock);
+		free_pcppages_bulk(zone, to_drain, pcp, 0);
+		spin_unlock(&pcp->lock);
+		todo++;
+	}
+
+	return todo;
+}
+
 #ifdef CONFIG_NUMA
 /*
  * Called from the vmstat counter updater to drain pagesets of this
@@ -2317,14 +2352,13 @@ static bool free_unref_page_prepare(struct page *page, unsigned long pfn,
 	return true;
 }
 
-static int nr_pcp_free(struct per_cpu_pages *pcp, int high, bool free_high)
+static int nr_pcp_free(struct per_cpu_pages *pcp, int batch, int high, bool free_high)
 {
 	int min_nr_free, max_nr_free;
-	int batch = READ_ONCE(pcp->batch);
 
-	/* Free everything if batch freeing high-order pages. */
+	/* Free as much as possible if batch freeing high-order pages. */
 	if (unlikely(free_high))
-		return pcp->count;
+		return min(pcp->count, batch << CONFIG_PCP_BATCH_SCALE_MAX);
 
 	/* Check for PCP disabled or boot pageset */
 	if (unlikely(high < batch))
@@ -2335,59 +2369,107 @@ static int nr_pcp_free(struct per_cpu_pages *pcp, int high, bool free_high)
 	max_nr_free = high - batch;
 
 	/*
-	 * Double the number of pages freed each time there is subsequent
-	 * freeing of pages without any allocation.
+	 * Increase the batch number to the number of the consecutive
+	 * freed pages to reduce zone lock contention.
 	 */
-	batch <<= pcp->free_factor;
-	if (batch < max_nr_free)
-		pcp->free_factor++;
-	batch = clamp(batch, min_nr_free, max_nr_free);
+	batch = clamp_t(int, pcp->free_count, min_nr_free, max_nr_free);
 
 	return batch;
 }
 
 static int nr_pcp_high(struct per_cpu_pages *pcp, struct zone *zone,
-		       bool free_high)
+		       int batch, bool free_high)
 {
-	int high = READ_ONCE(pcp->high);
+	int high, high_min, high_max;
+
+	high_min = READ_ONCE(pcp->high_min);
+	high_max = READ_ONCE(pcp->high_max);
+	high = pcp->high = clamp(pcp->high, high_min, high_max);
 
-	if (unlikely(!high || free_high))
+	if (unlikely(!high))
 		return 0;
 
-	if (!test_bit(ZONE_RECLAIM_ACTIVE, &zone->flags))
-		return high;
+	if (unlikely(free_high)) {
+		pcp->high = max(high - (batch << CONFIG_PCP_BATCH_SCALE_MAX),
+				high_min);
+		return 0;
+	}
 
 	/*
 	 * If reclaim is active, limit the number of pages that can be
 	 * stored on pcp lists
 	 */
-	return min(READ_ONCE(pcp->batch) << 2, high);
+	if (test_bit(ZONE_RECLAIM_ACTIVE, &zone->flags)) {
+		int free_count = max_t(int, pcp->free_count, batch);
+
+		pcp->high = max(high - free_count, high_min);
+		return min(batch << 2, pcp->high);
+	}
+
+	if (high_min == high_max)
+		return high;
+
+	if (test_bit(ZONE_BELOW_HIGH, &zone->flags)) {
+		int free_count = max_t(int, pcp->free_count, batch);
+
+		pcp->high = max(high - free_count, high_min);
+		high = max(pcp->count, high_min);
+	} else if (pcp->count >= high) {
+		int need_high = pcp->free_count + batch;
+
+		/* pcp->high should be large enough to hold batch freed pages */
+		if (pcp->high < need_high)
+			pcp->high = clamp(need_high, high_min, high_max);
+	}
+
+	return high;
 }
 
 static void free_unref_page_commit(struct zone *zone, struct per_cpu_pages *pcp,
 				   struct page *page, int migratetype,
 				   unsigned int order)
 {
-	int high;
+	int high, batch;
 	int pindex;
-	bool free_high;
+	bool free_high = false;
 
+	/*
+	 * On freeing, reduce the number of pages that are batch allocated.
+	 * See nr_pcp_alloc() where alloc_factor is increased for subsequent
+	 * allocations.
+	 */
+	pcp->alloc_factor >>= 1;
 	__count_vm_events(PGFREE, 1 << order);
 	pindex = order_to_pindex(migratetype, order);
 	list_add(&page->pcp_list, &pcp->lists[pindex]);
 	pcp->count += 1 << order;
 
+	batch = READ_ONCE(pcp->batch);
 	/*
 	 * As high-order pages other than THP's stored on PCP can contribute
 	 * to fragmentation, limit the number stored when PCP is heavily
 	 * freeing without allocation. The remainder after bulk freeing
 	 * stops will be drained from vmstat refresh context.
 	 */
-	free_high = (pcp->free_factor && order && order <= PAGE_ALLOC_COSTLY_ORDER);
-
-	high = nr_pcp_high(pcp, zone, free_high);
+	if (order && order <= PAGE_ALLOC_COSTLY_ORDER) {
+		free_high = (pcp->free_count >= batch &&
+			     (pcp->flags & PCPF_PREV_FREE_HIGH_ORDER) &&
+			     (!(pcp->flags & PCPF_FREE_HIGH_BATCH) ||
+			      pcp->count >= READ_ONCE(batch)));
+		pcp->flags |= PCPF_PREV_FREE_HIGH_ORDER;
+	} else if (pcp->flags & PCPF_PREV_FREE_HIGH_ORDER) {
+		pcp->flags &= ~PCPF_PREV_FREE_HIGH_ORDER;
+	}
+	if (pcp->free_count < (batch << CONFIG_PCP_BATCH_SCALE_MAX))
+		pcp->free_count += (1 << order);
+	high = nr_pcp_high(pcp, zone, batch, free_high);
 	if (pcp->count >= high) {
-		free_pcppages_bulk(zone, nr_pcp_free(pcp, high, free_high), pcp, pindex);
+		free_pcppages_bulk(zone, nr_pcp_free(pcp, batch, high, free_high),
+				   pcp, pindex);
+		if (test_bit(ZONE_BELOW_HIGH, &zone->flags) &&
+		    zone_watermark_ok(zone, 0, high_wmark_pages(zone),
+				      ZONE_MOVABLE, 0))
+			clear_bit(ZONE_BELOW_HIGH, &zone->flags);
 	}
 }
 
@@ -2671,6 +2753,56 @@ struct page *rmqueue_buddy(struct zone *preferred_zone, struct zone *zone,
 	return page;
 }
 
+static int nr_pcp_alloc(struct per_cpu_pages *pcp, struct zone *zone, int order)
+{
+	int high, base_batch, batch, max_nr_alloc;
+	int high_max, high_min;
+
+	base_batch = READ_ONCE(pcp->batch);
+	high_min = READ_ONCE(pcp->high_min);
+	high_max = READ_ONCE(pcp->high_max);
+	high = pcp->high = clamp(pcp->high, high_min, high_max);
+
+	/* Check for PCP disabled or boot pageset */
+	if (unlikely(high < base_batch))
+		return 1;
+
+	if (order)
+		batch = base_batch;
+	else
+		batch = (base_batch << pcp->alloc_factor);
+
+	/*
+	 * If we had larger pcp->high, we could avoid to allocate from
+	 * zone.
+	 */
+	if (high_min != high_max && !test_bit(ZONE_BELOW_HIGH, &zone->flags))
+		high = pcp->high = min(high + batch, high_max);
+
+	if (!order) {
+		max_nr_alloc = max(high - pcp->count - base_batch, base_batch);
+		/*
+		 * Double the number of pages allocated each time there is
+		 * subsequent allocation of order-0 pages without any freeing.
+		 */
+		if (batch <= max_nr_alloc &&
+		    pcp->alloc_factor < CONFIG_PCP_BATCH_SCALE_MAX)
+			pcp->alloc_factor++;
+		batch = min(batch, max_nr_alloc);
+	}
+
+	/*
+	 * Scale batch relative to order if batch implies free pages
+	 * can be stored on the PCP. Batch can be 1 for small zones or
+	 * for boot pagesets which should never store free pages as
+	 * the pages may belong to arbitrary zones.
+	 */
+	if (batch > 1)
+		batch = max(batch >> order, 2);
+
+	return batch;
+}
+
 /* Remove page from the per-cpu list, caller must protect the list */
 static inline
 struct page *__rmqueue_pcplist(struct zone *zone, unsigned int order,
@@ -2683,18 +2815,9 @@ struct page *__rmqueue_pcplist(struct zone *zone, unsigned int order,
 
 	do {
 		if (list_empty(list)) {
-			int batch = READ_ONCE(pcp->batch);
+			int batch = nr_pcp_alloc(pcp, zone, order);
 			int alloced;
 
-			/*
-			 * Scale batch relative to order if batch implies
-			 * free pages can be stored on the PCP. Batch can
-			 * be 1 for small zones or for boot pagesets which
-			 * should never store free pages as the pages may
-			 * belong to arbitrary zones.
-			 */
-			if (batch > 1)
-				batch = max(batch >> order, 2);
 			alloced = rmqueue_bulk(zone, order,
 					batch, list,
 					migratetype, alloc_flags);
@@ -2735,7 +2858,7 @@ static struct page *rmqueue_pcplist(struct zone *preferred_zone,
 	 * See nr_pcp_free() where free_factor is increased for subsequent
 	 * frees.
 	 */
-	pcp->free_factor >>= 1;
+	pcp->free_count >>= 1;
 	list = &pcp->lists[order_to_pindex(migratetype, order)];
 	page = __rmqueue_pcplist(zone, order, migratetype, alloc_flags, pcp, list);
 	pcp_spin_unlock(pcp);
@@ -3115,6 +3238,25 @@ retry:
 			}
 		}
 
+		/*
+		 * Detect whether the number of free pages is below high
+		 * watermark.  If so, we will decrease pcp->high and free
+		 * PCP pages in free path to reduce the possibility of
+		 * premature page reclaiming.  Detection is done here to
+		 * avoid to do that in hotter free path.
+		 */
+		if (test_bit(ZONE_BELOW_HIGH, &zone->flags))
+			goto check_alloc_wmark;
+
+		mark = high_wmark_pages(zone);
+		if (zone_watermark_fast(zone, order, mark,
+					ac->highest_zoneidx, alloc_flags,
+					gfp_mask))
+			goto try_this_zone;
+		else
+			set_bit(ZONE_BELOW_HIGH, &zone->flags);
+
+check_alloc_wmark:
 		mark = wmark_pages(zone, alloc_flags & ALLOC_WMARK_MASK);
 		if (!zone_watermark_fast(zone, order, mark,
 				       ac->highest_zoneidx, alloc_flags,
@@ -4456,12 +4598,8 @@ struct folio *__folio_alloc(gfp_t gfp, unsigned int order, int preferred_nid,
 		nodemask_t *nodemask)
 {
 	struct page *page = __alloc_pages(gfp | __GFP_COMP, order,
-			preferred_nid, nodemask);
-	struct folio *folio = (struct folio *)page;
-
-	if (folio && order > 1)
-		folio_prep_large_rmappable(folio);
-	return folio;
+					preferred_nid, nodemask);
+	return page_rmappable_folio(page);
 }
 EXPORT_SYMBOL(__folio_alloc);
 
@@ -4878,8 +5016,11 @@ int find_next_best_node(int node, nodemask_t *used_node_mask)
 	int min_val = INT_MAX;
 	int best_node = NUMA_NO_NODE;
 
-	/* Use the local node if we haven't already */
-	if (!node_isset(node, *used_node_mask)) {
+	/*
+	 * Use the local node if we haven't already, but for memoryless local
+	 * node, we should skip it and fall back to other nodes.
+	 */
+	if (!node_isset(node, *used_node_mask) && node_state(node, N_MEMORY)) {
 		node_set(node, *used_node_mask);
 		return node;
 	}
@@ -5255,14 +5396,15 @@ static int zone_batchsize(struct zone *zone)
 }
 
 static int percpu_pagelist_high_fraction;
-static int zone_highsize(struct zone *zone, int batch, int cpu_online)
+static int zone_highsize(struct zone *zone, int batch, int cpu_online,
+			 int high_fraction)
 {
 #ifdef CONFIG_MMU
 	int high;
 	int nr_split_cpus;
 	unsigned long total_pages;
 
-	if (!percpu_pagelist_high_fraction) {
+	if (!high_fraction) {
 		/*
 		 * By default, the high value of the pcp is based on the zone
 		 * low watermark so that if they are full then background
@@ -5275,15 +5417,15 @@ static int zone_highsize(struct zone *zone, int batch, int cpu_online)
 		 * value is based on a fraction of the managed pages in the
 		 * zone.
 		 */
-		total_pages = zone_managed_pages(zone) / percpu_pagelist_high_fraction;
+		total_pages = zone_managed_pages(zone) / high_fraction;
 	}
 
 	/*
 	 * Split the high value across all online CPUs local to the zone. Note
 	 * that early in boot that CPUs may not be online yet and that during
 	 * CPU hotplug that the cpumask is not yet updated when a CPU is being
-	 * onlined. For memory nodes that have no CPUs, split pcp->high across
-	 * all online CPUs to mitigate the risk that reclaim is triggered
+	 * onlined. For memory nodes that have no CPUs, split the high value
+	 * across all online CPUs to mitigate the risk that reclaim is triggered
 	 * prematurely due to pages stored on pcp lists.
 	 */
 	nr_split_cpus = cpumask_weight(cpumask_of_node(zone_to_nid(zone))) + cpu_online;
@@ -5311,19 +5453,21 @@ static int zone_highsize(struct zone *zone, int batch, int cpu_online)
  * However, guaranteeing these relations at all times would require e.g. write
  * barriers here but also careful usage of read barriers at the read side, and
  * thus be prone to error and bad for performance. Thus the update only prevents
- * store tearing. Any new users of pcp->batch and pcp->high should ensure they
- * can cope with those fields changing asynchronously, and fully trust only the
- * pcp->count field on the local CPU with interrupts disabled.
+ * store tearing. Any new users of pcp->batch, pcp->high_min and pcp->high_max
+ * should ensure they can cope with those fields changing asynchronously, and
+ * fully trust only the pcp->count field on the local CPU with interrupts
+ * disabled.
  *
  * mutex_is_locked(&pcp_batch_high_lock) required when calling this function
  * outside of boot time (or some other assurance that no concurrent updaters
  * exist).
  */
-static void pageset_update(struct per_cpu_pages *pcp, unsigned long high,
-		unsigned long batch)
+static void pageset_update(struct per_cpu_pages *pcp, unsigned long high_min,
+			   unsigned long high_max, unsigned long batch)
 {
 	WRITE_ONCE(pcp->batch, batch);
-	WRITE_ONCE(pcp->high, high);
+	WRITE_ONCE(pcp->high_min, high_min);
+	WRITE_ONCE(pcp->high_max, high_max);
 }
 
 static void per_cpu_pages_init(struct per_cpu_pages *pcp, struct per_cpu_zonestat *pzstats)
@@ -5343,20 +5487,21 @@ static void per_cpu_pages_init(struct per_cpu_pages *pcp, struct per_cpu_zonesta
 	 * need to be as careful as pageset_update() as nobody can access the
 	 * pageset yet.
 	 */
-	pcp->high = BOOT_PAGESET_HIGH;
+	pcp->high_min = BOOT_PAGESET_HIGH;
+	pcp->high_max = BOOT_PAGESET_HIGH;
 	pcp->batch = BOOT_PAGESET_BATCH;
-	pcp->free_factor = 0;
+	pcp->free_count = 0;
 }
 
-static void __zone_set_pageset_high_and_batch(struct zone *zone, unsigned long high,
-		unsigned long batch)
+static void __zone_set_pageset_high_and_batch(struct zone *zone, unsigned long high_min,
+					      unsigned long high_max, unsigned long batch)
 {
 	struct per_cpu_pages *pcp;
 	int cpu;
 
 	for_each_possible_cpu(cpu) {
 		pcp = per_cpu_ptr(zone->per_cpu_pageset, cpu);
-		pageset_update(pcp, high, batch);
+		pageset_update(pcp, high_min, high_max, batch);
 	}
 }
 
@@ -5366,19 +5511,34 @@ static void __zone_set_pageset_high_and_batch(struct zone *zone, unsigned long h
  */
 static void zone_set_pageset_high_and_batch(struct zone *zone, int cpu_online)
 {
-	int new_high, new_batch;
+	int new_high_min, new_high_max, new_batch;
 
 	new_batch = max(1, zone_batchsize(zone));
-	new_high = zone_highsize(zone, new_batch, cpu_online);
+	if (percpu_pagelist_high_fraction) {
+		new_high_min = zone_highsize(zone, new_batch, cpu_online,
+					     percpu_pagelist_high_fraction);
+		/*
+		 * PCP high is tuned manually, disable auto-tuning via
+		 * setting high_min and high_max to the manual value.
+		 */
+		new_high_max = new_high_min;
+	} else {
+		new_high_min = zone_highsize(zone, new_batch, cpu_online, 0);
+		new_high_max = zone_highsize(zone, new_batch, cpu_online,
+					     MIN_PERCPU_PAGELIST_HIGH_FRACTION);
+	}
 
-	if (zone->pageset_high == new_high &&
+	if (zone->pageset_high_min == new_high_min &&
+	    zone->pageset_high_max == new_high_max &&
 	    zone->pageset_batch == new_batch)
 		return;
 
-	zone->pageset_high = new_high;
+	zone->pageset_high_min = new_high_min;
+	zone->pageset_high_max = new_high_max;
 	zone->pageset_batch = new_batch;
 
-	__zone_set_pageset_high_and_batch(zone, new_high, new_batch);
+	__zone_set_pageset_high_and_batch(zone, new_high_min, new_high_max,
+					  new_batch);
 }
 
 void __meminit setup_zone_pageset(struct zone *zone)
@@ -5413,6 +5573,39 @@ static void zone_pcp_update(struct zone *zone, int cpu_online)
 	mutex_unlock(&pcp_batch_high_lock);
 }
 
+static void zone_pcp_update_cacheinfo(struct zone *zone)
+{
+	int cpu;
+	struct per_cpu_pages *pcp;
+	struct cpu_cacheinfo *cci;
+
+	for_each_online_cpu(cpu) {
+		pcp = per_cpu_ptr(zone->per_cpu_pageset, cpu);
+		cci = get_cpu_cacheinfo(cpu);
+		/*
+		 * If data cache slice of CPU is large enough, "pcp->batch"
+		 * pages can be preserved in PCP before draining PCP for
+		 * consecutive high-order pages freeing without allocation.
+		 * This can reduce zone lock contention without hurting
+		 * cache-hot pages sharing.
+		 */
+		spin_lock(&pcp->lock);
+		if ((cci->per_cpu_data_slice_size >> PAGE_SHIFT) > 3 * pcp->batch)
+			pcp->flags |= PCPF_FREE_HIGH_BATCH;
+		else
+			pcp->flags &= ~PCPF_FREE_HIGH_BATCH;
+		spin_unlock(&pcp->lock);
+	}
+}
+
+void setup_pcp_cacheinfo(void)
+{
+	struct zone *zone;
+
+	for_each_populated_zone(zone)
+		zone_pcp_update_cacheinfo(zone);
+}
+
 /*
  * Allocate per cpu pagesets and initialize them.
  * Before this call only boot pagesets were available.
@@ -5454,7 +5647,8 @@ __meminit void zone_pcp_init(struct zone *zone)
 	 */
 	zone->per_cpu_pageset = &boot_pageset;
 	zone->per_cpu_zonestats = &boot_zonestats;
-	zone->pageset_high = BOOT_PAGESET_HIGH;
+	zone->pageset_high_min = BOOT_PAGESET_HIGH;
+	zone->pageset_high_max = BOOT_PAGESET_HIGH;
 	zone->pageset_batch = BOOT_PAGESET_BATCH;
 
 	if (populated_zone(zone))
@@ -6356,13 +6550,14 @@ EXPORT_SYMBOL(free_contig_range);
 void zone_pcp_disable(struct zone *zone)
 {
 	mutex_lock(&pcp_batch_high_lock);
-	__zone_set_pageset_high_and_batch(zone, 0, 1);
+	__zone_set_pageset_high_and_batch(zone, 0, 0, 1);
 	__drain_all_pages(zone, true);
 }
 
 void zone_pcp_enable(struct zone *zone)
 {
-	__zone_set_pageset_high_and_batch(zone, zone->pageset_high, zone->pageset_batch);
+	__zone_set_pageset_high_and_batch(zone, zone->pageset_high_min,
+		zone->pageset_high_max, zone->pageset_batch);
 	mutex_unlock(&pcp_batch_high_lock);
 }
 
@@ -6462,28 +6657,24 @@ static void break_down_buddy_pages(struct zone *zone, struct page *page,
 				   int migratetype)
 {
 	unsigned long size = 1 << high;
-	struct page *current_buddy, *next_page;
+	struct page *current_buddy;
 
 	while (high > low) {
 		high--;
 		size >>= 1;
 
 		if (target >= &page[size]) {
-			next_page = page + size;
 			current_buddy = page;
+			page = page + size;
 		} else {
-			next_page = page;
 			current_buddy = page + size;
 		}
-		page = next_page;
 
 		if (set_page_guard(zone, current_buddy, high, migratetype))
 			continue;
 
-		if (current_buddy != target) {
-			add_to_free_list(current_buddy, zone, high, migratetype);
-			set_buddy_order(current_buddy, high);
-		}
+		add_to_free_list(current_buddy, zone, high, migratetype);
+		set_buddy_order(current_buddy, high);
 	}
 }