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From:   Yue Hu <zbestahu@gmail.com>
To:     akpm@linux-foundation.org, mhocko@suse.com, rientjes@google.com,
        joe@perches.com
Cc:     linux-mm@kvack.org, linux-kernel@vger.kernel.org, huyue2@yulong.com
Subject: [PATCH] mm/cma_debug: Avoid to use global cma_debugfs_root
Date:   Thu, 21 Feb 2019 12:01:29 +0800
Message-Id: <20190221040130.8940-1-zbestahu@gmail.com>
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

From: Yue Hu <huyue2@yulong.com>

Currently cma_debugfs_root is at global space. That is unnecessary
since it will be only used by next cma_debugfs_add_one(). We can
just pass it to following calling, it will save global space. Also
remove useless idx parameter.

Signed-off-by: Yue Hu <huyue2@yulong.com>
---
 mm/cma_debug.c | 9 ++++-----
 1 file changed, 4 insertions(+), 5 deletions(-)

diff --git a/mm/cma_debug.c b/mm/cma_debug.c
index f234672..2c2c869 100644
--- a/mm/cma_debug.c
+++ b/mm/cma_debug.c
@@ -21,8 +21,6 @@ struct cma_mem {
 	unsigned long n;
 };
 
-static struct dentry *cma_debugfs_root;
-
 static int cma_debugfs_get(void *data, u64 *val)
 {
 	unsigned long *p = data;
@@ -162,7 +160,7 @@ static int cma_alloc_write(void *data, u64 val)
 }
 DEFINE_SIMPLE_ATTRIBUTE(cma_alloc_fops, NULL, cma_alloc_write, "%llu\n");
 
-static void cma_debugfs_add_one(struct cma *cma, int idx)
+static void cma_debugfs_add_one(struct cma *cma, struct dentry *root_dentry)
 {
 	struct dentry *tmp;
 	char name[16];
@@ -170,7 +168,7 @@ static void cma_debugfs_add_one(struct cma *cma, int idx)
 
 	scnprintf(name, sizeof(name), "cma-%s", cma->name);
 
-	tmp = debugfs_create_dir(name, cma_debugfs_root);
+	tmp = debugfs_create_dir(name, root_dentry);
 
 	debugfs_create_file("alloc", 0200, tmp, cma, &cma_alloc_fops);
 	debugfs_create_file("free", 0200, tmp, cma, &cma_free_fops);
@@ -188,6 +186,7 @@ static void cma_debugfs_add_one(struct cma *cma, int idx)
 
 static int __init cma_debugfs_init(void)
 {
+	struct dentry *cma_debugfs_root;
 	int i;
 
 	cma_debugfs_root = debugfs_create_dir("cma", NULL);
@@ -195,7 +194,7 @@ static int __init cma_debugfs_init(void)
 		return -ENOMEM;
 
 	for (i = 0; i < cma_area_count; i++)
-		cma_debugfs_add_one(&cma_areas[i], i);
+		cma_debugfs_add_one(&cma_areas[i], cma_debugfs_root);
 
 	return 0;
 }
-- 
1.9.1