From 12b9804419cfb1c1bdac413f6c373af3b88d154b Mon Sep 17 00:00:00 2001
From: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Date: Fri, 25 Jul 2008 01:47:19 -0700
Subject: [PATCH] res_counter: limit change support ebusy
Add an interface to set limit. This is necessary to memory resource
controller because it shrinks usage at set limit.
Other controllers may not need this interface to shrink usage because
shrinking is not necessary or impossible.
Acked-by: Balbir Singh <balbir@linux.vnet.ibm.com>
Acked-by: Pavel Emelyanov <xemul@openvz.org>
Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Paul Menage <menage@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
---
include/linux/res_counter.h | 16 ++++++++++++++++
1 file changed, 16 insertions(+)
diff --git a/include/linux/res_counter.h b/include/linux/res_counter.h
index 290205dfe094..fdeadd9740dc 100644
--- a/include/linux/res_counter.h
+++ b/include/linux/res_counter.h
@@ -158,4 +158,20 @@ static inline void res_counter_reset_failcnt(struct res_counter *cnt)
cnt->failcnt = 0;
spin_unlock_irqrestore(&cnt->lock, flags);
}
+
+static inline int res_counter_set_limit(struct res_counter *cnt,
+ unsigned long long limit)
+{
+ unsigned long flags;
+ int ret = -EBUSY;
+
+ spin_lock_irqsave(&cnt->lock, flags);
+ if (cnt->usage < limit) {
+ cnt->limit = limit;
+ ret = 0;
+ }
+ spin_unlock_irqrestore(&cnt->lock, flags);
+ return ret;
+}
+
#endif
--
2.20.1