CGroup API files: add res_counter_read_u64()

Adds a function for returning the value of a resource counter member, in a
form suitable for use in a cgroup read_u64 control file method.

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, 5 insertions, 0 deletions

diff --git a/kernel/res_counter.c b/kernel/res_counter.c
index a508c2769463..70587657dda3 100644
--- a/kernel/res_counter.c
+++ b/kernel/res_counter.c
@@ -93,6 +93,11 @@ ssize_t res_counter_read(struct res_counter *counter, int member,
                         pos, buf, s - buf);
 }
 
+u64 res_counter_read_u64(struct res_counter *counter, int member)
+{
+        return *res_counter_member(counter, member);
+}
+
 ssize_t res_counter_write(struct res_counter *counter, int member,
                 const char __user *userbuf, size_t nbytes, loff_t *pos,
                 int (*write_strategy)(char *st_buf, unsigned long long *val))