diff options
Diffstat (limited to 'mm/shrinker_debug.c')
| -rw-r--r-- | mm/shrinker_debug.c | 61 |
1 files changed, 19 insertions, 42 deletions
diff --git a/mm/shrinker_debug.c b/mm/shrinker_debug.c index 3ab53fad8876..20eaee3e97f7 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; @@ -117,9 +113,8 @@ 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); + read_len = min(size, sizeof(kbuf) - 1); if (copy_from_user(kbuf, buf, read_len)) return -EFAULT; kbuf[read_len] = '\0'; @@ -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) @@ -207,8 +195,6 @@ int shrinker_debugfs_add(struct shrinker *shrinker) int shrinker_debugfs_rename(struct shrinker *shrinker, const char *fmt, ...) { - struct dentry *entry; - char buf[128]; const char *new, *old; va_list ap; int ret = 0; @@ -220,27 +206,21 @@ 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; - if (shrinker->debugfs_entry) { - snprintf(buf, sizeof(buf), "%s-%d", shrinker->name, - shrinker->debugfs_id); - - entry = debugfs_rename(shrinker_debugfs_root, - shrinker->debugfs_entry, - shrinker_debugfs_root, buf); - if (IS_ERR(entry)) - ret = PTR_ERR(entry); - else - shrinker->debugfs_entry = entry; - } - - up_write(&shrinker_rwsem); + ret = debugfs_change_name(shrinker->debugfs_entry, "%s-%d", + shrinker->name, shrinker->debugfs_id); - kfree_const(old); + if (ret) { + shrinker->name = old; + kfree_const(new); + } else { + kfree_const(old); + } + mutex_unlock(&shrinker_mutex); return ret; } @@ -251,10 +231,7 @@ 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 +257,14 @@ 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; } |