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Diffstat (limited to 'mm/shrinker_debug.c')
-rw-r--r--mm/shrinker_debug.c35
1 files changed, 10 insertions, 25 deletions
diff --git a/mm/shrinker_debug.c b/mm/shrinker_debug.c
index 3ab53fad8876..12ea5486a3e9 100644
--- a/mm/shrinker_debug.c
+++ b/mm/shrinker_debug.c
@@ -6,8 +6,10 @@
#include <linux/shrinker.h>
#include <linux/memcontrol.h>
+#include "internal.h"
+
/* defined in vmscan.c */
-extern struct rw_semaphore shrinker_rwsem;
+extern struct mutex shrinker_mutex;
extern struct list_head shrinker_list;
static DEFINE_IDA(shrinker_debugfs_ida);
@@ -49,17 +51,12 @@ static int shrinker_debugfs_count_show(struct seq_file *m, void *v)
struct mem_cgroup *memcg;
unsigned long total;
bool memcg_aware;
- int ret, nid;
+ int ret = 0, nid;
count_per_node = kcalloc(nr_node_ids, sizeof(unsigned long), GFP_KERNEL);
if (!count_per_node)
return -ENOMEM;
- ret = down_read_killable(&shrinker_rwsem);
- if (ret) {
- kfree(count_per_node);
- return ret;
- }
rcu_read_lock();
memcg_aware = shrinker->flags & SHRINKER_MEMCG_AWARE;
@@ -92,7 +89,6 @@ static int shrinker_debugfs_count_show(struct seq_file *m, void *v)
} while ((memcg = mem_cgroup_iter(NULL, memcg, NULL)) != NULL);
rcu_read_unlock();
- up_read(&shrinker_rwsem);
kfree(count_per_node);
return ret;
@@ -117,7 +113,6 @@ static ssize_t shrinker_debugfs_scan_write(struct file *file,
struct mem_cgroup *memcg = NULL;
int nid;
char kbuf[72];
- ssize_t ret;
read_len = size < (sizeof(kbuf) - 1) ? size : (sizeof(kbuf) - 1);
if (copy_from_user(kbuf, buf, read_len))
@@ -146,12 +141,6 @@ static ssize_t shrinker_debugfs_scan_write(struct file *file,
return -EINVAL;
}
- ret = down_read_killable(&shrinker_rwsem);
- if (ret) {
- mem_cgroup_put(memcg);
- return ret;
- }
-
sc.nid = nid;
sc.memcg = memcg;
sc.nr_to_scan = nr_to_scan;
@@ -159,7 +148,6 @@ static ssize_t shrinker_debugfs_scan_write(struct file *file,
shrinker->scan_objects(shrinker, &sc);
- up_read(&shrinker_rwsem);
mem_cgroup_put(memcg);
return size;
@@ -177,7 +165,7 @@ int shrinker_debugfs_add(struct shrinker *shrinker)
char buf[128];
int id;
- lockdep_assert_held(&shrinker_rwsem);
+ lockdep_assert_held(&shrinker_mutex);
/* debugfs isn't initialized yet, add debugfs entries later. */
if (!shrinker_debugfs_root)
@@ -220,7 +208,7 @@ int shrinker_debugfs_rename(struct shrinker *shrinker, const char *fmt, ...)
if (!new)
return -ENOMEM;
- down_write(&shrinker_rwsem);
+ mutex_lock(&shrinker_mutex);
old = shrinker->name;
shrinker->name = new;
@@ -238,7 +226,7 @@ int shrinker_debugfs_rename(struct shrinker *shrinker, const char *fmt, ...)
shrinker->debugfs_entry = entry;
}
- up_write(&shrinker_rwsem);
+ mutex_unlock(&shrinker_mutex);
kfree_const(old);
@@ -251,10 +239,7 @@ struct dentry *shrinker_debugfs_detach(struct shrinker *shrinker,
{
struct dentry *entry = shrinker->debugfs_entry;
- lockdep_assert_held(&shrinker_rwsem);
-
- kfree_const(shrinker->name);
- shrinker->name = NULL;
+ lockdep_assert_held(&shrinker_mutex);
*debugfs_id = entry ? shrinker->debugfs_id : -1;
shrinker->debugfs_entry = NULL;
@@ -280,14 +265,14 @@ static int __init shrinker_debugfs_init(void)
shrinker_debugfs_root = dentry;
/* Create debugfs entries for shrinkers registered at boot */
- down_write(&shrinker_rwsem);
+ mutex_lock(&shrinker_mutex);
list_for_each_entry(shrinker, &shrinker_list, list)
if (!shrinker->debugfs_entry) {
ret = shrinker_debugfs_add(shrinker);
if (ret)
break;
}
- up_write(&shrinker_rwsem);
+ mutex_unlock(&shrinker_mutex);
return ret;
}