Thread (51 messages) 51 messages, 6 authors, 2025-07-25

Lifecycle

  1. Posted Nico Pache <npache@redhat.com>
  2. Reviewed-by Baolin Wang

[PATCH v9 12/14] khugepaged: improve tracepoints for mTHP orders

From: Nico Pache <npache@redhat.com>
Date: 2025-07-14 00:35:35
Also in: linux-doc, linux-mm, lkml
Subsystem: memory management, memory management - thp (transparent huge page), the rest, tracing · Maintainers: Andrew Morton, David Hildenbrand, Lorenzo Stoakes, Linus Torvalds, Steven Rostedt, Masami Hiramatsu

Add the order to the tracepoints to give better insight into what order
is being operated at for khugepaged.

Reviewed-by: Baolin Wang <baolin.wang@linux.alibaba.com>
Signed-off-by: Nico Pache <npache@redhat.com>
---
 include/trace/events/huge_memory.h | 34 +++++++++++++++++++-----------
 mm/khugepaged.c                    | 10 +++++----
 2 files changed, 28 insertions(+), 16 deletions(-)
diff --git a/include/trace/events/huge_memory.h b/include/trace/events/huge_memory.h
index 2305df6cb485..70661bbf676f 100644
--- a/include/trace/events/huge_memory.h
+++ b/include/trace/events/huge_memory.h
@@ -92,34 +92,37 @@ TRACE_EVENT(mm_khugepaged_scan_pmd,
 
 TRACE_EVENT(mm_collapse_huge_page,
 
-	TP_PROTO(struct mm_struct *mm, int isolated, int status),
+	TP_PROTO(struct mm_struct *mm, int isolated, int status, int order),
 
-	TP_ARGS(mm, isolated, status),
+	TP_ARGS(mm, isolated, status, order),
 
 	TP_STRUCT__entry(
 		__field(struct mm_struct *, mm)
 		__field(int, isolated)
 		__field(int, status)
+		__field(int, order)
 	),
 
 	TP_fast_assign(
 		__entry->mm = mm;
 		__entry->isolated = isolated;
 		__entry->status = status;
+		__entry->order = order;
 	),
 
-	TP_printk("mm=%p, isolated=%d, status=%s",
+	TP_printk("mm=%p, isolated=%d, status=%s order=%d",
 		__entry->mm,
 		__entry->isolated,
-		__print_symbolic(__entry->status, SCAN_STATUS))
+		__print_symbolic(__entry->status, SCAN_STATUS),
+		__entry->order)
 );
 
 TRACE_EVENT(mm_collapse_huge_page_isolate,
 
 	TP_PROTO(struct folio *folio, int none_or_zero,
-		 int referenced, bool  writable, int status),
+		 int referenced, bool  writable, int status, int order),
 
-	TP_ARGS(folio, none_or_zero, referenced, writable, status),
+	TP_ARGS(folio, none_or_zero, referenced, writable, status, order),
 
 	TP_STRUCT__entry(
 		__field(unsigned long, pfn)
@@ -127,6 +130,7 @@ TRACE_EVENT(mm_collapse_huge_page_isolate,
 		__field(int, referenced)
 		__field(bool, writable)
 		__field(int, status)
+		__field(int, order)
 	),
 
 	TP_fast_assign(
@@ -135,27 +139,31 @@ TRACE_EVENT(mm_collapse_huge_page_isolate,
 		__entry->referenced = referenced;
 		__entry->writable = writable;
 		__entry->status = status;
+		__entry->order = order;
 	),
 
-	TP_printk("scan_pfn=0x%lx, none_or_zero=%d, referenced=%d, writable=%d, status=%s",
+	TP_printk("scan_pfn=0x%lx, none_or_zero=%d, referenced=%d, writable=%d, status=%s order=%d",
 		__entry->pfn,
 		__entry->none_or_zero,
 		__entry->referenced,
 		__entry->writable,
-		__print_symbolic(__entry->status, SCAN_STATUS))
+		__print_symbolic(__entry->status, SCAN_STATUS),
+		__entry->order)
 );
 
 TRACE_EVENT(mm_collapse_huge_page_swapin,
 
-	TP_PROTO(struct mm_struct *mm, int swapped_in, int referenced, int ret),
+	TP_PROTO(struct mm_struct *mm, int swapped_in, int referenced, int ret,
+			int order),
 
-	TP_ARGS(mm, swapped_in, referenced, ret),
+	TP_ARGS(mm, swapped_in, referenced, ret, order),
 
 	TP_STRUCT__entry(
 		__field(struct mm_struct *, mm)
 		__field(int, swapped_in)
 		__field(int, referenced)
 		__field(int, ret)
+		__field(int, order)
 	),
 
 	TP_fast_assign(
@@ -163,13 +171,15 @@ TRACE_EVENT(mm_collapse_huge_page_swapin,
 		__entry->swapped_in = swapped_in;
 		__entry->referenced = referenced;
 		__entry->ret = ret;
+		__entry->order = order;
 	),
 
-	TP_printk("mm=%p, swapped_in=%d, referenced=%d, ret=%d",
+	TP_printk("mm=%p, swapped_in=%d, referenced=%d, ret=%d, order=%d",
 		__entry->mm,
 		__entry->swapped_in,
 		__entry->referenced,
-		__entry->ret)
+		__entry->ret,
+		__entry->order)
 );
 
 TRACE_EVENT(mm_khugepaged_scan_file,
diff --git a/mm/khugepaged.c b/mm/khugepaged.c
index 65cb8c58bbf8..d0c99b86b304 100644
--- a/mm/khugepaged.c
+++ b/mm/khugepaged.c
@@ -711,13 +711,14 @@ static int __collapse_huge_page_isolate(struct vm_area_struct *vma,
 	} else {
 		result = SCAN_SUCCEED;
 		trace_mm_collapse_huge_page_isolate(folio, none_or_zero,
-						    referenced, writable, result);
+						    referenced, writable, result,
+						    order);
 		return result;
 	}
 out:
 	release_pte_pages(pte, _pte, compound_pagelist);
 	trace_mm_collapse_huge_page_isolate(folio, none_or_zero,
-					    referenced, writable, result);
+					    referenced, writable, result, order);
 	return result;
 }
 
@@ -1097,7 +1098,8 @@ static int __collapse_huge_page_swapin(struct mm_struct *mm,
 
 	result = SCAN_SUCCEED;
 out:
-	trace_mm_collapse_huge_page_swapin(mm, swapped_in, referenced, result);
+	trace_mm_collapse_huge_page_swapin(mm, swapped_in, referenced, result,
+						order);
 	return result;
 }
 
@@ -1322,7 +1324,7 @@ static int collapse_huge_page(struct mm_struct *mm, unsigned long address,
 	*mmap_locked = false;
 	if (folio)
 		folio_put(folio);
-	trace_mm_collapse_huge_page(mm, result == SCAN_SUCCEED, result);
+	trace_mm_collapse_huge_page(mm, result == SCAN_SUCCEED, result, order);
 	return result;
 }
 
-- 
2.50.0
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