[RFC PATCH v2 04/16] mm: Define function to create a dir for each online node

[Juan Yescas <jyescas@google.com>]

This change creates a directory for each online node
in the system.

Signed-off-by: Juan Yescas <jyescas@google.com>
---

Changes in v2:
	- Fix comments.
	- Use for_each_node_state(nid, N_MEMORY) instead.

 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 175f479c487b..5765ecc43567 100644
--- a/mm/page_alloc_hogger.c
+++ b/mm/page_alloc_hogger.c
@@ -89,6 +89,7 @@
 #include <linux/gfp_types.h>
 #include <linux/kernel.h>
 #include <linux/module.h>
+#include <linux/nodemask.h>
 #include <linux/printk.h>
 #include <linux/slab.h>
 
@@ -125,6 +126,26 @@ struct page_alloc {
 static struct kmem_cache *req_alloc_cache;
 static struct kmem_cache *page_alloc_cache;
 
+/**
+ * create_nodes_subdirs() - Creates a directory for each node that contains
+ * memory.
+ */
+static inline int create_nodes_subdirs(struct dentry *mmdir)
+{
+	struct dentry *nodedir;
+	int nid;
+	char dirname[12];
+
+	for_each_node_state(nid, N_MEMORY) {
+		snprintf(dirname, sizeof(dirname), "node-%d", nid);
+		nodedir = debugfs_create_dir(dirname, mmdir);
+		if (IS_ERR(nodedir))
+			return PTR_ERR(nodedir);
+	}
+
+	return 0;
+}
+
 static int __init page_alloc_hogger_debugfs_init(void)
 {
 	int ret;
@@ -154,8 +175,15 @@ static int __init page_alloc_hogger_debugfs_init(void)
 		goto clean_page_alloc_cache;
 	}
 
+	ret = create_nodes_subdirs(mmdir);
+	if (ret)
+		goto clean_dir;
+
 	return 0;
 
+clean_dir:
+	debugfs_remove_recursive(mmdir);
+
 clean_page_alloc_cache:
 	kmem_cache_destroy(page_alloc_cache);
 
-- 
2.55.0.629.g250fe7f194-goog