Add an interface to set limit. This is necessary to memory resource controller
because it shrinks usage at set limit.
(*) Other controller may not need this interface to shrink usage because
shrinking is not necessary or impossible.
This is an enhancement.
named as res_counter-limit-change-ebusy.patch
Changelog:
- fixed white space bug.
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>
include/linux/res_counter.h | 15 +++++++++++++++
1 file changed, 15 insertions(+)
Index: linux-2.6.26-rc8-mm1/include/linux/res_counter.h
===================================================================
--- linux-2.6.26-rc8-mm1.orig/include/linux/res_counter.h
+++ linux-2.6.26-rc8-mm1/include/linux/res_counter.h
@@ -176,4 +176,19 @@ static inline bool res_counter_can_add(s
return ret;
}
+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
--
