[PATCH v7 11/12] khugepaged: add per-order mTHP khugepaged stats
From: Nico Pache <npache@redhat.com>
Date: 2025-05-15 03:25:48
Also in:
linux-doc, linux-mm, lkml
Subsystem:
memory management, memory management - thp (transparent huge page), the rest · Maintainers:
Andrew Morton, David Hildenbrand, Lorenzo Stoakes, Linus Torvalds
With mTHP support inplace, let add the per-order mTHP stats for exceeding NONE, SWAP, and SHARED. Signed-off-by: Nico Pache <npache@redhat.com> --- include/linux/huge_mm.h | 3 +++ mm/huge_memory.c | 7 +++++++ mm/khugepaged.c | 15 ++++++++++++--- 3 files changed, 22 insertions(+), 3 deletions(-)
diff --git a/include/linux/huge_mm.h b/include/linux/huge_mm.h
index 0bb65bd4e6dd..e3d15c737008 100644
--- a/include/linux/huge_mm.h
+++ b/include/linux/huge_mm.h@@ -139,6 +139,9 @@ enum mthp_stat_item { MTHP_STAT_SPLIT_DEFERRED, MTHP_STAT_NR_ANON, MTHP_STAT_NR_ANON_PARTIALLY_MAPPED, + MTHP_STAT_COLLAPSE_EXCEED_SWAP, + MTHP_STAT_COLLAPSE_EXCEED_NONE, + MTHP_STAT_COLLAPSE_EXCEED_SHARED, __MTHP_STAT_COUNT };
diff --git a/mm/huge_memory.c b/mm/huge_memory.c
index 177f0a78666a..700988a0d5cf 100644
--- a/mm/huge_memory.c
+++ b/mm/huge_memory.c@@ -633,6 +633,10 @@ DEFINE_MTHP_STAT_ATTR(split_failed, MTHP_STAT_SPLIT_FAILED); DEFINE_MTHP_STAT_ATTR(split_deferred, MTHP_STAT_SPLIT_DEFERRED); DEFINE_MTHP_STAT_ATTR(nr_anon, MTHP_STAT_NR_ANON); DEFINE_MTHP_STAT_ATTR(nr_anon_partially_mapped, MTHP_STAT_NR_ANON_PARTIALLY_MAPPED); +DEFINE_MTHP_STAT_ATTR(collapse_exceed_swap_pte, MTHP_STAT_COLLAPSE_EXCEED_SWAP); +DEFINE_MTHP_STAT_ATTR(collapse_exceed_none_pte, MTHP_STAT_COLLAPSE_EXCEED_NONE); +DEFINE_MTHP_STAT_ATTR(collapse_exceed_shared_pte, MTHP_STAT_COLLAPSE_EXCEED_SHARED); + static struct attribute *anon_stats_attrs[] = { &anon_fault_alloc_attr.attr,
@@ -649,6 +653,9 @@ static struct attribute *anon_stats_attrs[] = { &split_deferred_attr.attr, &nr_anon_attr.attr, &nr_anon_partially_mapped_attr.attr, + &collapse_exceed_swap_pte_attr.attr, + &collapse_exceed_none_pte_attr.attr, + &collapse_exceed_shared_pte_attr.attr, NULL, };
diff --git a/mm/khugepaged.c b/mm/khugepaged.c
index 951c44778f56..0723b184c7a4 100644
--- a/mm/khugepaged.c
+++ b/mm/khugepaged.c@@ -604,7 +604,10 @@ static int __collapse_huge_page_isolate(struct vm_area_struct *vma, continue; } else { result = SCAN_EXCEED_NONE_PTE; - count_vm_event(THP_SCAN_EXCEED_NONE_PTE); + if (order == HPAGE_PMD_ORDER) + count_vm_event(THP_SCAN_EXCEED_NONE_PTE); + else + count_mthp_stat(order, MTHP_STAT_COLLAPSE_EXCEED_NONE); goto out; } }
@@ -633,8 +636,14 @@ static int __collapse_huge_page_isolate(struct vm_area_struct *vma, /* See khugepaged_scan_pmd(). */ if (folio_maybe_mapped_shared(folio)) { ++shared; - if (order != HPAGE_PMD_ORDER || (cc->is_khugepaged && - shared > khugepaged_max_ptes_shared)) { + if (order != HPAGE_PMD_ORDER) { + result = SCAN_EXCEED_SHARED_PTE; + count_mthp_stat(order, MTHP_STAT_COLLAPSE_EXCEED_SHARED); + goto out; + } + + if (cc->is_khugepaged && + shared > khugepaged_max_ptes_shared) { result = SCAN_EXCEED_SHARED_PTE; count_vm_event(THP_SCAN_EXCEED_SHARED_PTE); goto out;
--
2.49.0