+ mm-add-per-order-mthp-anon_swpout-and-anon_swpout_fallback-counters.patch added to mm-unstable branch

[Andrew Morton <akpm@linux-foundation.org>]

The patch titled
     Subject: mm: add per-order mTHP anon_swpout and anon_swpout_fallback counters
has been added to the -mm mm-unstable branch.  Its filename is
     mm-add-per-order-mthp-anon_swpout-and-anon_swpout_fallback-counters.patch

This patch will shortly appear at
     https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/mm-add-per-order-mthp-anon_swpout-and-anon_swpout_fallback-counters.patch

This patch will later appear in the mm-unstable branch at
    git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

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------------------------------------------------------
From: Barry Song <v-songbaohua@oppo.com>
Subject: mm: add per-order mTHP anon_swpout and anon_swpout_fallback counters
Date: Fri, 5 Apr 2024 23:27:04 +1300

This helps to display the fragmentation situation of the swapfile, knowing
the proportion of how much we haven't split large folios.  So far, we only
support non-split swapout for anon memory, with the possibility of
expanding to shmem in the future.  So, we add the "anon" prefix to the
counter names.

Link: https://lkml.kernel.org/r/20240405102704.77559-3-21cnbao@gmail.com
Signed-off-by: Barry Song <v-songbaohua@oppo.com>
Cc: Chris Li <chrisl@kernel.org>
Cc: David Hildenbrand <david@redhat.com>
Cc: Domenico Cerasuolo <cerasuolodomenico@gmail.com>
Cc: Kairui Song <kasong@tencent.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Peter Xu <peterx@redhat.com>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Yosry Ahmed <yosryahmed@google.com>
Cc: Yu Zhao <yuzhao@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 include/linux/huge_mm.h |    2 ++
 mm/huge_memory.c        |    4 ++++
 mm/page_io.c            |    6 +++++-
 mm/vmscan.c             |    3 +++
 4 files changed, 14 insertions(+), 1 deletion(-)

--- a/include/linux/huge_mm.h~mm-add-per-order-mthp-anon_swpout-and-anon_swpout_fallback-counters
+++ a/include/linux/huge_mm.h
@@ -267,6 +267,8 @@ unsigned long thp_vma_allowable_orders(s
 enum mthp_stat_item {
 	MTHP_STAT_ANON_ALLOC,
 	MTHP_STAT_ANON_ALLOC_FALLBACK,
+	MTHP_STAT_ANON_SWPOUT,
+	MTHP_STAT_ANON_SWPOUT_FALLBACK,
 	__MTHP_STAT_COUNT
 };
 
--- a/mm/huge_memory.c~mm-add-per-order-mthp-anon_swpout-and-anon_swpout_fallback-counters
+++ a/mm/huge_memory.c
@@ -554,10 +554,14 @@ static struct kobj_attribute _name##_att
 
 DEFINE_MTHP_STAT_ATTR(anon_alloc, MTHP_STAT_ANON_ALLOC);
 DEFINE_MTHP_STAT_ATTR(anon_alloc_fallback, MTHP_STAT_ANON_ALLOC_FALLBACK);
+DEFINE_MTHP_STAT_ATTR(anon_swpout, MTHP_STAT_ANON_SWPOUT);
+DEFINE_MTHP_STAT_ATTR(anon_swpout_fallback, MTHP_STAT_ANON_SWPOUT_FALLBACK);
 
 static struct attribute *stats_attrs[] = {
 	&anon_alloc_attr.attr,
 	&anon_alloc_fallback_attr.attr,
+	&anon_swpout_attr.attr,
+	&anon_swpout_fallback_attr.attr,
 	NULL,
 };
 
--- a/mm/page_io.c~mm-add-per-order-mthp-anon_swpout-and-anon_swpout_fallback-counters
+++ a/mm/page_io.c
@@ -212,13 +212,17 @@ int swap_writepage(struct page *page, st
 
 static inline void count_swpout_vm_event(struct folio *folio)
 {
+	long nr_pages = folio_nr_pages(folio);
+
 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
 	if (unlikely(folio_test_pmd_mappable(folio))) {
 		count_memcg_folio_events(folio, THP_SWPOUT, 1);
 		count_vm_event(THP_SWPOUT);
 	}
+	if (nr_pages > 0)
+		count_mthp_stat(folio_order(folio), MTHP_STAT_ANON_SWPOUT);
 #endif
-	count_vm_events(PSWPOUT, folio_nr_pages(folio));
+	count_vm_events(PSWPOUT, nr_pages);
 }
 
 #if defined(CONFIG_MEMCG) && defined(CONFIG_BLK_CGROUP)
--- a/mm/vmscan.c~mm-add-per-order-mthp-anon_swpout-and-anon_swpout_fallback-counters
+++ a/mm/vmscan.c
@@ -1230,6 +1230,9 @@ retry:
 						count_vm_event(
 							THP_SWPOUT_FALLBACK);
 					}
+					if (nr_pages > 0)
+						count_mthp_stat(get_order(nr_pages * PAGE_SIZE),
+							MTHP_STAT_ANON_SWPOUT_FALLBACK);
 #endif
 					if (!add_to_swap(folio))
 						goto activate_locked_split;
_

Patches currently in -mm which might be from v-songbaohua@oppo.com are

arm64-mm-swap-support-thp_swap-on-hardware-with-mte.patch
mm-hold-ptl-from-the-first-pte-while-reclaiming-a-large-folio.patch
mm-alloc_anon_folio-avoid-doing-vma_thp_gfp_mask-in-fallback-cases.patch
mm-add-per-order-mthp-anon_alloc-and-anon_alloc_fallback-counters.patch
mm-add-per-order-mthp-anon_swpout-and-anon_swpout_fallback-counters.patch