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Diffstat (limited to 'mm/shrinker_debug.c')
-rw-r--r--mm/shrinker_debug.c54
1 files changed, 34 insertions, 20 deletions
diff --git a/mm/shrinker_debug.c b/mm/shrinker_debug.c
index 3f83b10c5031..3ab53fad8876 100644
--- a/mm/shrinker_debug.c
+++ b/mm/shrinker_debug.c
@@ -5,12 +5,10 @@
#include <linux/seq_file.h>
#include <linux/shrinker.h>
#include <linux/memcontrol.h>
-#include <linux/srcu.h>
/* defined in vmscan.c */
-extern struct mutex shrinker_mutex;
+extern struct rw_semaphore shrinker_rwsem;
extern struct list_head shrinker_list;
-extern struct srcu_struct shrinker_srcu;
static DEFINE_IDA(shrinker_debugfs_ida);
static struct dentry *shrinker_debugfs_root;
@@ -51,13 +49,18 @@ static int shrinker_debugfs_count_show(struct seq_file *m, void *v)
struct mem_cgroup *memcg;
unsigned long total;
bool memcg_aware;
- int ret = 0, nid, srcu_idx;
+ int ret, nid;
count_per_node = kcalloc(nr_node_ids, sizeof(unsigned long), GFP_KERNEL);
if (!count_per_node)
return -ENOMEM;
- srcu_idx = srcu_read_lock(&shrinker_srcu);
+ ret = down_read_killable(&shrinker_rwsem);
+ if (ret) {
+ kfree(count_per_node);
+ return ret;
+ }
+ rcu_read_lock();
memcg_aware = shrinker->flags & SHRINKER_MEMCG_AWARE;
@@ -88,7 +91,8 @@ static int shrinker_debugfs_count_show(struct seq_file *m, void *v)
}
} while ((memcg = mem_cgroup_iter(NULL, memcg, NULL)) != NULL);
- srcu_read_unlock(&shrinker_srcu, srcu_idx);
+ rcu_read_unlock();
+ up_read(&shrinker_rwsem);
kfree(count_per_node);
return ret;
@@ -111,8 +115,9 @@ static ssize_t shrinker_debugfs_scan_write(struct file *file,
.gfp_mask = GFP_KERNEL,
};
struct mem_cgroup *memcg = NULL;
- int nid, srcu_idx;
+ 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))
@@ -141,7 +146,11 @@ static ssize_t shrinker_debugfs_scan_write(struct file *file,
return -EINVAL;
}
- srcu_idx = srcu_read_lock(&shrinker_srcu);
+ ret = down_read_killable(&shrinker_rwsem);
+ if (ret) {
+ mem_cgroup_put(memcg);
+ return ret;
+ }
sc.nid = nid;
sc.memcg = memcg;
@@ -150,7 +159,7 @@ static ssize_t shrinker_debugfs_scan_write(struct file *file,
shrinker->scan_objects(shrinker, &sc);
- srcu_read_unlock(&shrinker_srcu, srcu_idx);
+ up_read(&shrinker_rwsem);
mem_cgroup_put(memcg);
return size;
@@ -168,7 +177,7 @@ int shrinker_debugfs_add(struct shrinker *shrinker)
char buf[128];
int id;
- lockdep_assert_held(&shrinker_mutex);
+ lockdep_assert_held(&shrinker_rwsem);
/* debugfs isn't initialized yet, add debugfs entries later. */
if (!shrinker_debugfs_root)
@@ -211,7 +220,7 @@ int shrinker_debugfs_rename(struct shrinker *shrinker, const char *fmt, ...)
if (!new)
return -ENOMEM;
- mutex_lock(&shrinker_mutex);
+ down_write(&shrinker_rwsem);
old = shrinker->name;
shrinker->name = new;
@@ -229,7 +238,7 @@ int shrinker_debugfs_rename(struct shrinker *shrinker, const char *fmt, ...)
shrinker->debugfs_entry = entry;
}
- mutex_unlock(&shrinker_mutex);
+ up_write(&shrinker_rwsem);
kfree_const(old);
@@ -237,23 +246,28 @@ int shrinker_debugfs_rename(struct shrinker *shrinker, const char *fmt, ...)
}
EXPORT_SYMBOL(shrinker_debugfs_rename);
-struct dentry *shrinker_debugfs_remove(struct shrinker *shrinker)
+struct dentry *shrinker_debugfs_detach(struct shrinker *shrinker,
+ int *debugfs_id)
{
struct dentry *entry = shrinker->debugfs_entry;
- lockdep_assert_held(&shrinker_mutex);
+ lockdep_assert_held(&shrinker_rwsem);
kfree_const(shrinker->name);
shrinker->name = NULL;
- if (entry) {
- ida_free(&shrinker_debugfs_ida, shrinker->debugfs_id);
- shrinker->debugfs_entry = NULL;
- }
+ *debugfs_id = entry ? shrinker->debugfs_id : -1;
+ shrinker->debugfs_entry = NULL;
return entry;
}
+void shrinker_debugfs_remove(struct dentry *debugfs_entry, int debugfs_id)
+{
+ debugfs_remove_recursive(debugfs_entry);
+ ida_free(&shrinker_debugfs_ida, debugfs_id);
+}
+
static int __init shrinker_debugfs_init(void)
{
struct shrinker *shrinker;
@@ -266,14 +280,14 @@ static int __init shrinker_debugfs_init(void)
shrinker_debugfs_root = dentry;
/* Create debugfs entries for shrinkers registered at boot */
- mutex_lock(&shrinker_mutex);
+ down_write(&shrinker_rwsem);
list_for_each_entry(shrinker, &shrinker_list, list)
if (!shrinker->debugfs_entry) {
ret = shrinker_debugfs_add(shrinker);
if (ret)
break;
}
- mutex_unlock(&shrinker_mutex);
+ up_write(&shrinker_rwsem);
return ret;
}