We don't want memory cgroup support to be enabled by default, due to the run-time overhead. Below is a patch that allows the code to be included but disabled by default. However, memory cgroup support still has some run-time cost when included but disabled, which we need to evaluate before making this change.
Ben.
diff --git a/init/Kconfig b/init/Kconfig
index eb4b337..47b2dcf 100644
--- a/init/Kconfig
+++ b/init/Kconfig
@@ -579,6 +579,14 @@ config CGROUP_MEM_RES_CTLR
This config option also selects MM_OWNER config option, which
could in turn add some fork/exit overhead.
+config CGROUP_MEM_RES_CTLR_DISABLED
+ bool "Memory Resource Controller disabled by default"
+ depends on CGROUP_MEM_RES_CTLR
+ default n
+ help
+ Disable the memory group resource controller unless explicitly
+ enabled using the kernel parameter "cgroup_enable=memory".
+
config CGROUP_MEM_RES_CTLR_SWAP
bool "Memory Resource Controller Swap Extension(EXPERIMENTAL)"
depends on CGROUP_MEM_RES_CTLR && SWAP && EXPERIMENTAL
diff --git a/kernel/cgroup.c b/kernel/cgroup.c
index 1fbcc74..4f6be6c 100644
--- a/kernel/cgroup.c
+++ b/kernel/cgroup.c
@@ -3791,7 +3791,7 @@ static void cgroup_release_agent(struct work_struct *work)
mutex_unlock(&cgroup_mutex);
}
-static int __init cgroup_disable(char *str)
+static int __init cgroup_set_disabled(char *str, int value)
{
int i;
char *token;
@@ -3804,17 +3804,29 @@ static int __init cgroup_disable(char *str)
struct cgroup_subsys *ss = subsys[i];
if (!strcmp(token, ss->name)) {
- ss->disabled = 1;
- printk(KERN_INFO "Disabling %s control group"
- " subsystem\n", ss->name);
+ ss->disabled = value;
+ printk(KERN_INFO
+ "%sabling %s control group subsystem\n",
+ value ? "Dis" : "En", ss->name);
break;
}
}
}
return 1;
}
+
+static int __init cgroup_disable(char *str)
+{
+ cgroup_set_disabled(str, 1);
+}
__setup("cgroup_disable=", cgroup_disable);
+static int __init cgroup_enable(char *str)
+{
+ cgroup_set_disabled(str, 0);
+}
+__setup("cgroup_enable=", cgroup_enable);
+
/*
* Functons for CSS ID.
*/
diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index 66035bf..58897ce 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -3184,6 +3184,9 @@ static void mem_cgroup_move_task(struct cgroup_subsys *ss,
struct cgroup_subsys mem_cgroup_subsys = {
.name = "memory",
+#ifdef CONFIG_CGROUP_MEM_RES_CTLR_DISABLED
+ .disabled = 1,
+#endif
.subsys_id = mem_cgroup_subsys_id,
.create = mem_cgroup_create,
.pre_destroy = mem_cgroup_pre_destroy,
--- END ---
--
Ben Hutchings
If you seem to know what you are doing, you'll be given more to do.
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