Changelog v1
1. Split cgroup_disable into cgroup_disable and cgroup_enable

2. Remove cgroup_toggle
Due to the overhead of the memory controller. The

memory controller is now disabled by default. This patch adds cgroup_enable.
If everyone agrees on this approach and likes it, should we push this

into 2.6.25?
Signed-off-by: Balbir Singh <balbir@linux.vnet.ibm.com>

---
 Documentation/kernel-parameters.txt |    3 +++

 kernel/cgroup.c                     |   28 ++++++++++++++++++++++++++--

 mm/memcontrol.c                     |    1 +

 3 files changed, 30 insertions(+), 2 deletions(-)
diff -puN kernel/cgroup.c~memory-controller-default-option-off kernel/cgroup.c

--- linux-2.6.25-rc8/kernel/cgroup.c~memory-controller-default-option-off	2008-04-07 16:24:28.000000000 +0530

+++ linux-2.6.25-rc8-balbir/kernel/cgroup.c	2008-04-07 18:30:31.000000000 +0530

@@ -3077,8 +3077,8 @@ static int __init cgroup_disable(char *s
 			if (!strcmp(token, ss->name)) {

 				ss->disabled = 1;

-				printk(KERN_INFO "Disabling %s control group"

-					" subsystem\n", ss->name);

+				printk(KERN_INFO "%s control group "

+						"is disabled\n", ss->name);

 				break;

 			}

 		}

@@ -3086,3 +3086,27 @@ static int __init cgroup_disable(char *s

 	return 1;

 }

 __setup("cgroup_disable=", cgroup_disable);

+

+static int __init cgroup_enable(char *str)

+{

+	int i;

+	char *token;

+

+	while ((token = strsep(&str, ",")) != NULL) {

+		if (!*token)

+			continue;

+

+		for (i = 0; i < CGROUP_SUBSYS_COUNT; i++) {

+			struct cgroup_subsys *ss = subsys[i];

+

+			if (!strcmp(token, ss->name)) {

+				ss->disabled = 0;

+				printk(KERN_INFO "%s control group "

+						"is enabled\n", ss->name);

+				break;

+			}

+		}

+	}

+	return 1;

+}

+__setup("cgroup_enable=", cgroup_enable);

diff -puN mm/memcontrol.c~memory-controller-default-option-off mm/memcontrol.c

--- linux-2.6.25-rc8/mm/memcontrol.c~memory-controller-default-option-off	2008-04-07 16:24:28.000000000 +0530...
[ message continues ]

On Mon, 07 Apr 2008 18:32:15 +0530

BTW, how the user can know which controllers are on/off at default ?

All controllers are off ?
Thanks,

-Kame
--

/proc/cgroups has an enabled field (fourth one). That should show what is

enabled/disabled. I've also documented it in

Documentation/kernel-parameters.txt. I intend to enable the memory controller

again, once we bring down the overhead.
--

	Warm Regards,

	Balbir Singh

	Linux Technology Center

	IBM, ISTL

--

Good idea - but you could just use the same handler function for both

of these (with a one-line wrapper for each to pass disabled=1 or

disabled=0)
Paul

--

Acked-by: KOSAKI Motohiro<kosaki.motohiro@jp.fujitsu.com>

--