mm: shmem: add mTHP counters for anonymous shmem

Add mTHP counters for anonymous shmem.

[[email protected]: update Documentation/admin-guide/mm/transhuge.rst]
  Link: https://lkml.kernel.org/r/[email protected]
Link: https://lkml.kernel.org/r/4fd9e467d49ae4a747e428bcd821c7d13125ae67.1718090413.git.baolin.wang@linux.alibaba.com
Signed-off-by: Baolin Wang <[email protected]>
Reviewed-by: Lance Yang <[email protected]>
Cc: Barry Song <[email protected]>
Cc: Daniel Gomez <[email protected]>
Cc: David Hildenbrand <[email protected]>
Cc: "Huang, Ying" <[email protected]>
Cc: Hugh Dickins <[email protected]>
Cc: Kefeng Wang <[email protected]>
Cc: Pankaj Raghav <[email protected]>
Cc: Ryan Roberts <[email protected]>
Cc: Yang Shi <[email protected]>
Cc: Zi Yan <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>

4 files changed, 37 insertions, 3 deletions

diff --git a/Documentation/admin-guide/mm/transhuge.rst b/Documentation/admin-guide/mm/transhuge.rst
index e7232b46fe14..1f72b00af5d3 100644
--- a/Documentation/admin-guide/mm/transhuge.rst
+++ b/Documentation/admin-guide/mm/transhuge.rst
@@ -501,6 +501,19 @@ swpout_fallback
 	Usually because failed to allocate some continuous swap space
 	for the huge page.
 
+file_alloc
+	is incremented every time a file huge page is successfully
+	allocated.
+
+file_fallback
+	is incremented if a file huge page is attempted to be allocated
+	but fails and instead falls back to using small pages.
+
+file_fallback_charge
+	is incremented if a file huge page cannot be charged and instead
+	falls back to using small pages even though the allocation was
+	successful.
+
 As the system ages, allocating huge pages may be expensive as the
 system uses memory compaction to copy data around memory to free a
 huge page for use. There are some counters in ``/proc/vmstat`` to help
diff --git a/include/linux/huge_mm.h b/include/linux/huge_mm.h
index 53b7a137f460..7ad41de5eaea 100644
--- a/include/linux/huge_mm.h
+++ b/include/linux/huge_mm.h
@@ -281,6 +281,9 @@ enum mthp_stat_item {
 	MTHP_STAT_ANON_FAULT_FALLBACK_CHARGE,
 	MTHP_STAT_SWPOUT,
 	MTHP_STAT_SWPOUT_FALLBACK,
+	MTHP_STAT_FILE_ALLOC,
+	MTHP_STAT_FILE_FALLBACK,
+	MTHP_STAT_FILE_FALLBACK_CHARGE,
 	__MTHP_STAT_COUNT
 };
 
diff --git a/mm/huge_memory.c b/mm/huge_memory.c
index af6f239b0f97..f55362a73e2d 100644
--- a/mm/huge_memory.c
+++ b/mm/huge_memory.c
@@ -556,6 +556,9 @@ DEFINE_MTHP_STAT_ATTR(anon_fault_fallback, MTHP_STAT_ANON_FAULT_FALLBACK);
 DEFINE_MTHP_STAT_ATTR(anon_fault_fallback_charge, MTHP_STAT_ANON_FAULT_FALLBACK_CHARGE);
 DEFINE_MTHP_STAT_ATTR(swpout, MTHP_STAT_SWPOUT);
 DEFINE_MTHP_STAT_ATTR(swpout_fallback, MTHP_STAT_SWPOUT_FALLBACK);
+DEFINE_MTHP_STAT_ATTR(file_alloc, MTHP_STAT_FILE_ALLOC);
+DEFINE_MTHP_STAT_ATTR(file_fallback, MTHP_STAT_FILE_FALLBACK);
+DEFINE_MTHP_STAT_ATTR(file_fallback_charge, MTHP_STAT_FILE_FALLBACK_CHARGE);
 
 static struct attribute *stats_attrs[] = {
 	&anon_fault_alloc_attr.attr,
@@ -563,6 +566,9 @@ static struct attribute *stats_attrs[] = {
 	&anon_fault_fallback_charge_attr.attr,
 	&swpout_attr.attr,
 	&swpout_fallback_attr.attr,
+	&file_alloc_attr.attr,
+	&file_fallback_attr.attr,
+	&file_fallback_charge_attr.attr,
 	NULL,
 };
 
diff --git a/mm/shmem.c b/mm/shmem.c
index 224162aa204b..d09c6bf1f28a 100644
--- a/mm/shmem.c
+++ b/mm/shmem.c
@@ -1772,6 +1772,9 @@ static struct folio *shmem_alloc_and_add_folio(struct vm_fault *vmf,
 
 			if (pages == HPAGE_PMD_NR)
 				count_vm_event(THP_FILE_FALLBACK);
+#ifdef CONFIG_TRANSPARENT_HUGEPAGE
+			count_mthp_stat(order, MTHP_STAT_FILE_FALLBACK);
+#endif
 			order = next_order(&suitable_orders, order);
 		}
 	} else {
@@ -1791,9 +1794,15 @@ allocated:
 		if (xa_find(&mapping->i_pages, &index,
 				index + pages - 1, XA_PRESENT)) {
 			error = -EEXIST;
-		} else if (pages == HPAGE_PMD_NR) {
-			count_vm_event(THP_FILE_FALLBACK);
-			count_vm_event(THP_FILE_FALLBACK_CHARGE);
+		} else if (pages > 1) {
+			if (pages == HPAGE_PMD_NR) {
+				count_vm_event(THP_FILE_FALLBACK);
+				count_vm_event(THP_FILE_FALLBACK_CHARGE);
+			}
+#ifdef CONFIG_TRANSPARENT_HUGEPAGE
+			count_mthp_stat(folio_order(folio), MTHP_STAT_FILE_FALLBACK);
+			count_mthp_stat(folio_order(folio), MTHP_STAT_FILE_FALLBACK_CHARGE);
+#endif
 		}
 		goto unlock;
 	}
@@ -2167,6 +2176,9 @@ repeat:
 		if (!IS_ERR(folio)) {
 			if (folio_test_pmd_mappable(folio))
 				count_vm_event(THP_FILE_ALLOC);
+#ifdef CONFIG_TRANSPARENT_HUGEPAGE
+			count_mthp_stat(folio_order(folio), MTHP_STAT_FILE_ALLOC);
+#endif
 			goto alloced;
 		}
 		if (PTR_ERR(folio) == -EEXIST)