CGroup API files: use cgroup map for memcontrol stats file

Remove the seq_file boilerplate used to construct the memcontrol stats map,
and instead use the new map representation for cgroup control files

Signed-off-by: Paul Menage <menage@google.com>
Cc: "Li Zefan" <lizf@cn.fujitsu.com>
Cc: Balbir Singh <balbir@in.ibm.com>
Cc: Paul Jackson <pj@sgi.com>
Cc: Pavel Emelyanov <xemul@openvz.org>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: "YAMAMOTO Takashi" <yamamoto@valinux.co.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 6 insertions, 22 deletions

diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index e227d7c5989f..496ab700e0a4 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -899,9 +899,9 @@ static const struct mem_cgroup_stat_desc {
         [MEM_CGROUP_STAT_RSS] = { "rss", PAGE_SIZE, },
 };
 
-static int mem_control_stat_show(struct seq_file *m, void *arg)
+static int mem_control_stat_show(struct cgroup *cont, struct cftype *cft,
+                                 struct cgroup_map_cb *cb)
 {
-        struct cgroup *cont = m->private;
         struct mem_cgroup *mem_cont = mem_cgroup_from_cont(cont);
         struct mem_cgroup_stat *stat = &mem_cont->stat;
         int i;
@@ -911,8 +911,7 @@ static int mem_control_stat_show(struct seq_file *m, void *arg)
 
                 val = mem_cgroup_read_stat(stat, i);
                 val *= mem_cgroup_stat_desc[i].unit;
-                seq_printf(m, "%s %lld\n", mem_cgroup_stat_desc[i].msg,
-                                (long long)val);
+                cb->fill(cb, mem_cgroup_stat_desc[i].msg, val);
         }
         /* showing # of active pages */
         {
@@ -922,27 +921,12 @@ static int mem_control_stat_show(struct seq_file *m, void *arg)
                                                 MEM_CGROUP_ZSTAT_INACTIVE);
                 active = mem_cgroup_get_all_zonestat(mem_cont,
                                                 MEM_CGROUP_ZSTAT_ACTIVE);
-                seq_printf(m, "active %ld\n", (active) * PAGE_SIZE);
-                seq_printf(m, "inactive %ld\n", (inactive) * PAGE_SIZE);
+                cb->fill(cb, "active", (active) * PAGE_SIZE);
+                cb->fill(cb, "inactive", (inactive) * PAGE_SIZE);
         }
         return 0;
 }
 
-static const struct file_operations mem_control_stat_file_operations = {
-        .read = seq_read,
-        .llseek = seq_lseek,
-        .release = single_release,
-};
-
-static int mem_control_stat_open(struct inode *unused, struct file *file)
-{
-        /* XXX __d_cont */
-        struct cgroup *cont = file->f_dentry->d_parent->d_fsdata;
-
-        file->f_op = &mem_control_stat_file_operations;
-        return single_open(file, mem_control_stat_show, cont);
-}
-
 static struct cftype mem_cgroup_files[] = {
         {
                 .name = "usage_in_bytes",
@@ -967,7 +951,7 @@ static struct cftype mem_cgroup_files[] = {
         },
         {
                 .name = "stat",
-                .open = mem_control_stat_open,
+                .read_map = mem_control_stat_show,
         },
 };