[RFC PATCH 06/16] mm: Define function to create a dir for each page order

From: Juan Yescas

Date: Thu Jul 23 2026 - 03:53:25 EST


This change creates a directory for each page order inside
the zone directory.

Signed-off-by: Juan Yescas <jyescas@xxxxxxxxxx>
---
mm/page_alloc_hogger.c | 28 ++++++++++++++++++++++++++++
1 file changed, 28 insertions(+)

diff --git a/mm/page_alloc_hogger.c b/mm/page_alloc_hogger.c
index 1cec9ec5e35e..de86b8526338 100644
--- a/mm/page_alloc_hogger.c
+++ b/mm/page_alloc_hogger.c
@@ -127,6 +127,28 @@ struct page_alloc {
struct kmem_cache *req_alloc_cache;
struct kmem_cache *page_alloc_cache;

+/**
+ * create_page_orders_subdirs() - Creates a directory for each page order inside
+ * the zone directory. Once that the page order directory is created, it creates
+ * a directory for each migrate type.
+ */
+static inline int create_page_orders_subdirs(struct dentry *zonedir,
+ int node_idx, int zone_idx,
+ struct zone *zone)
+{
+ struct dentry *orderdir;
+ char dirname[12];
+
+ for (int order = 0; order < NR_PAGE_ORDERS; order++) {
+ snprintf(dirname, sizeof(dirname), "order-%d", order);
+ orderdir = debugfs_create_dir(dirname, zonedir);
+ if (IS_ERR(orderdir))
+ return PTR_ERR(orderdir);
+ }
+
+ return 0;
+}
+
/**
* create_zones_subdirs() - Creates a directory for each populated zone in the
* node. Once that the zone directory is created, it creates a directory for
@@ -143,6 +165,7 @@ static inline int create_zones_subdirs(struct dentry *nodedir, int node_idx,
struct zone *node_zones = pgdata->node_zones;
int zone_idx;
char dirname[24];
+ int ret;

for (zone = node_zones, zone_idx = 0; zone - node_zones < MAX_NR_ZONES;
++zone, ++zone_idx) {
@@ -157,6 +180,11 @@ static inline int create_zones_subdirs(struct dentry *nodedir, int node_idx,
zonedir = debugfs_create_dir(dirname, nodedir);
if (IS_ERR(zonedir))
return PTR_ERR(zonedir);
+
+ ret = create_page_orders_subdirs(zonedir, node_idx, zone_idx,
+ zone);
+ if (ret)
+ return ret;
}

return 0;
--
2.55.0.229.g6434b31f56-goog